• Title/Summary/Keyword: Work Factor

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Comparison of Treatment Planning System(TPS) and actual Measurement on the surface under the electron beam therapy with bolus (전자선 치료 시 Bolus를 적용한 경우 표면선량의 Treatment Planning System(TPS) 계산 값과 실제 측정값의 비교)

  • Kim, Byeong Soo;Park, Ju Young;Park, Byoung Suk;Song, Yong Min;Park, Byung Soo;Song, Ki Weon
    • The Journal of Korean Society for Radiation Therapy
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    • v.26 no.2
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    • pp.163-170
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    • 2014
  • Purpose : If electron, chosen for superficial oncotherapy, was applied with bolus, it could work as an important factor to a therapy result by showing a drastic change in surface dose. Hence the calculation value and the actual measurement value of surface dose of Treatment Planning System (TPS) according to four variables influencing surface dose when using bolus on an electron therapy were compared and analyzed in this paper. Materials and Methods : Four variables which frequently occur during the actual therapies (A: bolus thickness - 3, 5, 10 mm, B: field size - $6{\time}6$, $10{\time}10$, $15{\time}15cm2$, C: energy - 6, 9, 12 MeV, D: gantry angle - $0^{\circ}$, $15^{\circ}$) were set to compare the actual measurement value with TPS(Pinnacle 9.2, philips, USA). A computed tomography (lightspeed ultra 16, General Electric, USA) was performed using 16 cm-thick solid water phantom without bolus and total 54 beams where A, B, C, and D were combined after creating 3, 5 and 10 mm bolus on TPS were planned for a therapy. At this moment SSD 100 cm, 300 MU was investigated and measured twice repeatedly by placing it on iso-center by using EBT3 film(International Specialty Products, NJ, USA) to compare and analyze the actual measurement value and TPS. Measured film was analyzed with each average value and standard deviation value using digital flat bed scanner (Expression 10000XL, EPSON, USA) and dose density analyzing system (Complete Version 6.1, RIT, USA). Results : For the values according to the thickness of bolus, the actual measured values for 3, 5 and 10 mm were 101.41%, 99.58% and 101.28% higher respectively than the calculation values of TPS and the standard deviations were 0.0219, 0.0115 and 0.0190 respectively. The actual values according to the field size were $6{\time}6$, $10{\time}10$ and $15{\time}15cm2$ which were 99.63%, 101.40% and 101.24% higher respectively than the calculation values and the standard deviations were 0.0138, 0.0176 and 0.0220. The values according to energy were 6, 9, and 12 MeV which were 99.72%, 100.60% and 101.96% higher respectively and the standard deviations were 0.0200, 0.0160 and 0.0164. The actual measurement value according to beam angle were measured 100.45% and 101.07% higher at $0^{\circ}$ and $15^{\circ}$ respectively and standard deviations were 0.0199 and 0.0190 so they were measured 0.62% higher at $15^{\circ}$ than $0^{\circ}$. Conclusion : As a result of analyzing the calculation value of TPS and measurement value according to the used variables in this paper, the values calculated with TPS on 5 mm bolus, $6{\time}6cm2$ field size and low-energy electron at $0^{\circ}$ gantry angle were closer to the measured values, however, it showed a modest difference within the error bound of maximum 2%. If it was beyond the bounds of variables selected in this paper using electron and bolus simultaneously, the actual measurement value could differ from TPS according to each variable, therefore QA for the accurate surface dose would have to be performed.

Social division of labor in the traditional industry district - foursed on Damyang bamboo ware industry of Damyang and Yeoju pottery industry of Yeoju, South Korea (우리나라 재래공업 산지의 사회적 분업 - 담양죽제품과 여주 도자기 산지를 사례로 -)

  • ;;;Park, Yang-Choon;Lee, Chul-Woo;Park, Soon-Ho
    • Journal of the Korean Geographical Society
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    • v.30 no.3
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    • pp.269-295
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    • 1995
  • This research is concerned with the social division of labor within the traditional industry district: Damyang bamboo ware industry district and Yeoju pottery industry district in South Korea, Damyang bamboo ware and Yeoju pottery are well known of the Korean traditional industry. The social division of labor in an industry district is considered as an important factor. The social division of labor helps the traditional industry to survive today. This summary shows five significant points from the major findings. First, Damyang bamoo ware industry and Yoeju pottery industry have experienced the growth stages until 1945, the stagnation in the 1960s, and the business recovery in the 1980s. Most Korean traditional industries had been radically declined under the Japanese colonization; while, Damyang bamboo ware industry and Yeoju pottery industry district have been developed during above all stages. The extended market to Japan helped the local government to establish a training center, and to provide financial aids and technical aids to crafts men. During the 1960s and 1970s, mass production of substitute goods on factory system resulted in the decrease of demand of bamboo ware and pettery. During the 1980s, these industries have slowly recovered as a result of the increased income per capita. The high rate of economic growth in the 1960s and 1970s was playing an important role in the emerging the incleased demand of the bamboo ware and pottery. Second the production-and-marketing system in a traditional industry district became diversified to adjust the demand of products. In Damyang bamboo ware industry district, the level of social division of labor was low until the high economic development period. Bamboo ware were made by a farmer in a small domestic system, The bamboo goods were mainly sold in the periodic market of bamboo ware in Damyang. In the recession period in the 1960s and 1970s, the production-and-marketing system were diversified; a manufacturing-wholesale type business and small-factory type business became established; and the wholesale business and the export traders in the district appeared. In the recovery period in the 1980s, the production-and-marketing systems were more diversified; a small-factory type business started to depend On subcontractors for a part of process of production; and a wholesale business in the district engaged in production of bamboo ware. In Yeoju pottery industry district, the social division of labor was limited until the early 1970s. A pottery was made by a crafts man in a small-business of domestic system and sold by a middle man out of Yeoju. Since the late 1970s, production-and-marketing system become being diversified as a result of the increased demand in Japan and South Korea. In the 1970s, Korean traditional craft pottery was highiy demanded in Japan. The demand encouraged people in Yoeju to become craftsmen and/or to work in the pottery related occupation. In South Korea, the rapid economic growth resulted in incline to pottery due to the development of stainless and plastic bowls and dishes. The production facilities were modernized to provide pottery at the reasonable price. A small-busineas of domestic system was transformed into a small-factory type business. The social division of labor was intensified in the pottery production-and-maketing system. The manufacturing kaoline began to be seperated from the production process of pottery. Within the district, a pottery wholesale business and a retail business started to be established in the 1980s. Third the traditional industry district was divided into "completed one" and "not-completed one" according to whether or not the district firms led the function of the social division of labor. The Damyang bamboo ware industry district is "completed one": the firm within the district is in charge of the supply of raw material, the production and the marketing. In the Damyang bamboo ware district, the social division of labor w and reorganized labor system to improve the external economics effect through intensifying the social division of labor. Lastly, the social division of labor was playing an important role in the development of traditional industry districts. The subdivision of production process and the diversification of business reduced the production cost and overcame the labor shortage through hiring low-waged workers such as family members, the old people and housewives. An enterpriser with small amount of capital easily joined into the business. The risk from business recession were dispersed. The accumulated know-how in the production and maketing provided flexiblility to produce various goods and to extend the life-cycly of a product.d the life-cycly of a product.

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Measuring Intracellular Mycobacterial Killing Using a Human Whole Blood Assay (인체 전혈 모델을 이용한 세포내 결핵균 살균력에 관한 연구)

  • Cheon, Seon-Hee;Song, Ho-Yeon;Lee, Eun-Hee;Oh, Hee-Jung;Kang, In-Sook;Cho, Ji-Yoon;Hong, Young-Sun
    • Tuberculosis and Respiratory Diseases
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    • v.53 no.5
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    • pp.497-509
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    • 2002
  • Background : The mechanisms through which cellular activation results in intracellular mycobacterial killing is only partially understood. However, in vitro studies of human immunity to Mycobacterium tuberculosis have been largely modeled on the work reported by Crowle, which is complicated by several factors. The whole blood culture is simple and allows the simultaneous analysis of the relationship between bacterial killing and the effect of effector cells and humoral factors. In this study, we attempted to determine the extent to which M. tuberculosis is killed in a human whole blood culture and to explore the role of the host and microbial factor in this process. Methods : The PPD positive subject were compared to the umbilical cord blood and patients with tuberculosis, diabetes and lung cancer. The culture is performed using heparinized whole blood diluted with a culture medium and infected with a low number of M. avium or M. tuberculosis $H_{37}Ra$ for 4 days by rotating the culture in a $37^{\circ}C$, 5% $CO_2$ incubator. In some experiments, methlprednisolone- or pentoxifyline were used to inhibit the immune response. To assess the role of the T-cell subsets, CD4+, CD8+ T-cells or both were removed from the blood using magnetic beads. The ${\Delta}$ log killing ratio was defined using a CFU assay as the difference in the log number of viable organisms in the completed culture compared to the inoculum. Results : 1. A trend was noted toward the improved killing of mycobacteria in PPD+ subjects comparing to the umbilical cord blood but there was no specific difference in the patients with tuberculosis, diabetes and lung cancer. 2. Methylprednisolone and pentoxifyline adversely affected the killing in the PPD+ subjects umbilical cord blood and patients with tuberculosis. 3. The deletion of CD4+ or CD8+ T-lymphocytes adversely affected the killing of M. avium and M. tuberculosis $H_{37}Ra$ by PPD+ subjects. Deletion of both cell types had an additive effect, particularly in M. tuberculosis $H_{37}Ra$. 4. A significantly improved mycobacterial killing was noted after chemotherapy in patients with tuberculosis and the ${\Delta}$ logKR continuously decreased in a 3 and 4 days of whole blood culture. Conclusion : The in vitro bactericidal assay by human whole blood culture model was settled using a CFU assay. However, the host immunity to M. tuberculosis was not apparent in the human whole blood culture bactericidal assay, and patients with tuberculosis showed markedly improved bacterial killing after anti-tuberculous chemotherapy compared to before. The simplicity of a whole blood culture facilitates its inclusion in a clinical trial and it may have a potential role as a surrogate marker in a TB vaccine trial.

Relationship between Stress and Eating Habits of Adults in Ulsan (울산지역 성인 남녀의 스트레스와 식습관)

  • Kim, Hye-Kyung;Kim, Jin-Hee
    • Journal of Nutrition and Health
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    • v.42 no.6
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    • pp.536-546
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    • 2009
  • This study was done to investigate the effect of stress on appetite and eating habits, and other health-related behaviors. The subjects of this study consisted of 188 males and 224 females in Ulsan area. The results were as follows: When stressed, 56% (n = 231) of the subjects experienced a change in appetite and of these, 32% (n = 132) experienced an increased appetite. Stress-induced eating may be one factor contributing to the development of obesity. There was a gender-specific response to stress in which women are more likely to use food to deal with stress, whereas men are more likely to use alcohol consumption or smoking. It was found that types of stressors were individual (52.9%), social (50.7%), family relations (34.5%), work demands (34.2%) and physical environment (32.3%). Stress-induced symptoms of the subjects were anxiety (38.3%), headache (36.7%) and neck or shoulder aches (36.2%), and females experienced those symptoms more than males. Those older than 50 years had a higher eating habit score and lower stress score compared with younger subjects. There were significant differences between sex, age, occupation, family type, BMI, exercise, sleeping hours and eating habits or stress level. This study may be helpful in advancing findings in this area to better provide health professionals with appropriate counseling tools to improve the health of all individuals.

Performance and Carcass Ratio of Large-type Female Broiler at Different Stocking Densities (다양한 사육밀도에서 대형 육계 수컷의 생산성과 도체수율)

  • Na, Jae-Cheon;HwangBoa, Jong;Kim, Ji-Hyuk;Kang, Hwan-Gu;Kim, Min-Ji;Kim, Dong-Wook;Choi, Hee-Cheol;Hong, Eui-Chul
    • Korean Journal of Poultry Science
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    • v.39 no.4
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    • pp.305-310
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    • 2012
  • This work was carried out to investigate performance and carcass yield of large-type broilers at different stocking densities. Treatments were T1 (9.1 birds/$m^2$), T2 (10.3 birds/$m^2$) and T3 (11.5 birds/$m^2$) by the stocking density. Four hundred eight 1-day-old Arbor Acre broiler chicks were used for six weeks (starter, 0~1 wks; earlier, 1~3 wks; finisher, 3~6 wks) and divided into 3 treatments (4 replications/treatment, 30, 34 or 38 birds/replication). Research indexes were rearing viability ratio, body weight, body weight gain, feed intake, feed conversion ratio, production efficiency factor and carcass ratio. Rearing viability ratio (%) was 89% or more for all treatments and there was no significant difference on weekly rearing viability ratio (%). Body weight of T2 was the greatest and that of T3 was the lowest at 1 weeks old (P<0.05). Body weight gain of T2 was the greatest and that of T3 was the lowest at 0~1 weeks old (P<0.05). However, body weight gain of T3 was the greatest and that of T1 was the lowest at 1~2 weeks old (P<0.05). Body weight gain of T2 was the greatest as 3,031 g among treatments at 0~6 weeks old (P<0.05). Feed intakes of T1, T2 and T3 were 1,417 g, 1,265 g and 1,355 g, respectively, and that of T1 was the greatest among treatments (P<0.05). There was no significant difference on body weight, body weight gain and feed intake. Feed conversion ratio of T1 was the greatest among treatments at 1~2 wks, 3~4 wks and 0~6 wks old (P<0.05). Production efficiency factors of T1, T2 and T3 were 363.5, 388.3 and 358.3, respectively, and there was no significant difference among treatments. Wing meat ratio of T1 was the higher compared to other treatments at the age of 4 wk (P<0.05). There was no significant difference on carcass ratio and partial meat ratio among treatments. Neck meat ratio of T2 was the lowest among treatments (P<0.05). This result may provide the standard data of different stocking densities for large-type broiler and the further research is needed.

Effects of Market Orientation and Relationship Orientation with Suppliers on Business Performance in Animal Clinic Industry: Moderating Effects of Entrepreneur's Characteristics and Clinic Location (동물병원의 시장지향성과 공급업체와의 관계지향성이 동물병원 성과에 미치는 영향: 경영자의 특성과 동물병원 입지에 따른 조절효과)

  • Yoo, Dong-Keun;Suh, Seung-Won;Lee, Yong-Ki
    • Journal of Global Scholars of Marketing Science
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    • v.18 no.2
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    • pp.189-222
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    • 2008
  • This study developed a model to empirically investigate the effects of market orientation and relationship orientation with suppliers on business performance and examine the moderating effects of entrepreneur's characteristics (working tenure) and clinic's location. The data was collected from 200 animal clinics which belong to Korean Animal Hospital Association (KAHA)'s national conference in April, 2007. Descriptive statistic, factor analysis, reliability analysis, and regression analysis were conducted to analyze the data using SPSS/PC+ 12.0. The findings are as follows. First, the market orientation of animal clinics influences significantly both financial and non-financial performance. When the moderating effect of entrepreneur's working tenure is considered, market orientation has significant effect on animal clinic's financial and non-financial performance. However, when the moderating effect of animal clinic's location is considered, market orientation has not significant effect on animal clinic's financial and non-financial performance. Second, animal clinic's relationship orientation with suppliers mostly affects the financial and non-financial performance significantly. When entrepreneur's working tenure in the clinic is longer (above 4 years group), relationship orientation with suppliers significantly affects both financial and non-financial performance. Meanwhile, when the entrepreneur's working tenure in the clinic is shorter (less than 3 years group), relationship orientation with suppliers doesn't affect clinic's financial performance but affect non-financial performance partially. In other words, when entrepreneur's working tenure is shorter (less than 3 years group), market orientation more influences on clinic's financial and non-financial performance while relationship orientation with suppliers does less. It is thought that their relation with suppliers and relationship orientation activities with suppliers are less strongly established and maintained yet. So, they primarily focus on market orientation strategy when entrepreneur's working tenure is shorter. Third, when animal clinics are located in non-metropolitan area, relationship orientation with suppliers significantly affects financial and non-financial performance. However, when animal clinics are located in metropolitan area, it doesn't affect financial and non-financial performance either. It is thought that animal clinics which are located in non-metropolitan area need stronger relationship with suppliers and need support more from them as most of suppliers actively work in metropolitan area not in the non-metropolitan area and animal clinics in metropolitan area can easily get better market information than animal clinics in non-metropolitan area. Lastly, while the effect of the market orientation significantly influences animal clinic's business performance continuously, the effect of the relationship orientation differently influences business performance as it is moderated by entrepreneur's working tenure and animal clinic's location. So, relationship orientation with suppliers can be selectively applied to improve the clinic's financial and no-financial performance. In summary, both of animal clinic's marketing orientation and animal clinic's relationship orientation with suppliers positively influence their business performance. However, entrepreneur's working tenure and animal clinic location moderate the relationship between market orientation and relationship orientation and their business performance differently. This study is quite meaningful to empirically investigate the effects of both of market orientation and relationship orientation with suppliers on business performance and examine the moderating effects of entrepreneur's characteristics (working tenure) and clinic's location. And, as this kind of study has been very few in the context of animal clinic industry, it helps practically understand the effects of market orientation and relationship orientation with suppliers on the financial and non-financial performance in animal clinic industry. Furthermore, as the market conditions in animal clinic industry have been in difficulty for a few years, this study can help improve animal clinic's financial and non-financial business performance together with their suppliers as business partners. Lastly, this study can help find mid-term and long-term cooperation between animal clinics and their suppliers. This study has some limitations. So, care should be taken when generalizing the results of the study. First, our samples were collected from only the animal clinics industry. However, a comparison of the results presented here with those form other marketing contexts (e.g., general hospitals) would be worthwhile. Future comparative research will enhance the generality of our contingency theory cross industry context. Second, this study found that market orientation and relationship orientation affect business performance. However, there may be other antecedents, such as internal market orientation and relationship orientation with customers. Also, this research did not consider other moderators, such as overall market conditions, competitive situations, and power/conflict between suppliers and buyers in the relationship between market and relationship orientation and business performance.

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A Folksonomy Ranking Framework: A Semantic Graph-based Approach (폭소노미 사이트를 위한 랭킹 프레임워크 설계: 시맨틱 그래프기반 접근)

  • Park, Hyun-Jung;Rho, Sang-Kyu
    • Asia pacific journal of information systems
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    • v.21 no.2
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    • pp.89-116
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    • 2011
  • In collaborative tagging systems such as Delicious.com and Flickr.com, users assign keywords or tags to their uploaded resources, such as bookmarks and pictures, for their future use or sharing purposes. The collection of resources and tags generated by a user is called a personomy, and the collection of all personomies constitutes the folksonomy. The most significant need of the folksonomy users Is to efficiently find useful resources or experts on specific topics. An excellent ranking algorithm would assign higher ranking to more useful resources or experts. What resources are considered useful In a folksonomic system? Does a standard superior to frequency or freshness exist? The resource recommended by more users with mere expertise should be worthy of attention. This ranking paradigm can be implemented through a graph-based ranking algorithm. Two well-known representatives of such a paradigm are Page Rank by Google and HITS(Hypertext Induced Topic Selection) by Kleinberg. Both Page Rank and HITS assign a higher evaluation score to pages linked to more higher-scored pages. HITS differs from PageRank in that it utilizes two kinds of scores: authority and hub scores. The ranking objects of these pages are limited to Web pages, whereas the ranking objects of a folksonomic system are somewhat heterogeneous(i.e., users, resources, and tags). Therefore, uniform application of the voting notion of PageRank and HITS based on the links to a folksonomy would be unreasonable, In a folksonomic system, each link corresponding to a property can have an opposite direction, depending on whether the property is an active or a passive voice. The current research stems from the Idea that a graph-based ranking algorithm could be applied to the folksonomic system using the concept of mutual Interactions between entitles, rather than the voting notion of PageRank or HITS. The concept of mutual interactions, proposed for ranking the Semantic Web resources, enables the calculation of importance scores of various resources unaffected by link directions. The weights of a property representing the mutual interaction between classes are assigned depending on the relative significance of the property to the resource importance of each class. This class-oriented approach is based on the fact that, in the Semantic Web, there are many heterogeneous classes; thus, applying a different appraisal standard for each class is more reasonable. This is similar to the evaluation method of humans, where different items are assigned specific weights, which are then summed up to determine the weighted average. We can check for missing properties more easily with this approach than with other predicate-oriented approaches. A user of a tagging system usually assigns more than one tags to the same resource, and there can be more than one tags with the same subjectivity and objectivity. In the case that many users assign similar tags to the same resource, grading the users differently depending on the assignment order becomes necessary. This idea comes from the studies in psychology wherein expertise involves the ability to select the most relevant information for achieving a goal. An expert should be someone who not only has a large collection of documents annotated with a particular tag, but also tends to add documents of high quality to his/her collections. Such documents are identified by the number, as well as the expertise, of users who have the same documents in their collections. In other words, there is a relationship of mutual reinforcement between the expertise of a user and the quality of a document. In addition, there is a need to rank entities related more closely to a certain entity. Considering the property of social media that ensures the popularity of a topic is temporary, recent data should have more weight than old data. We propose a comprehensive folksonomy ranking framework in which all these considerations are dealt with and that can be easily customized to each folksonomy site for ranking purposes. To examine the validity of our ranking algorithm and show the mechanism of adjusting property, time, and expertise weights, we first use a dataset designed for analyzing the effect of each ranking factor independently. We then show the ranking results of a real folksonomy site, with the ranking factors combined. Because the ground truth of a given dataset is not known when it comes to ranking, we inject simulated data whose ranking results can be predicted into the real dataset and compare the ranking results of our algorithm with that of a previous HITS-based algorithm. Our semantic ranking algorithm based on the concept of mutual interaction seems to be preferable to the HITS-based algorithm as a flexible folksonomy ranking framework. Some concrete points of difference are as follows. First, with the time concept applied to the property weights, our algorithm shows superior performance in lowering the scores of older data and raising the scores of newer data. Second, applying the time concept to the expertise weights, as well as to the property weights, our algorithm controls the conflicting influence of expertise weights and enhances overall consistency of time-valued ranking. The expertise weights of the previous study can act as an obstacle to the time-valued ranking because the number of followers increases as time goes on. Third, many new properties and classes can be included in our framework. The previous HITS-based algorithm, based on the voting notion, loses ground in the situation where the domain consists of more than two classes, or where other important properties, such as "sent through twitter" or "registered as a friend," are added to the domain. Forth, there is a big difference in the calculation time and memory use between the two kinds of algorithms. While the matrix multiplication of two matrices, has to be executed twice for the previous HITS-based algorithm, this is unnecessary with our algorithm. In our ranking framework, various folksonomy ranking policies can be expressed with the ranking factors combined and our approach can work, even if the folksonomy site is not implemented with Semantic Web languages. Above all, the time weight proposed in this paper will be applicable to various domains, including social media, where time value is considered important.

Mechanical and Operational Factors Affecting the Efficiency of Rice Polishing Machines (정미기의 능률에 미치는 기계적 요인및 작동조건에 관한 연구)

  • No, Sang-Ha
    • Journal of Biosystems Engineering
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    • v.1 no.1
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    • pp.15-15
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    • 1976
  • In analyzing the operational characteristics of a rice whitening machine, the internal radial pressure of the machine was measured using strain gage equipment. Changes in cylinder and feed screw configurations, screen type, cylinder speed and counter-pressure levels were examined to determine their impact on the quality and quantity of milled rice and the performance of the machine. The results are summarized as follows: 1. The internal radial pressure in the whitening chamber varied with the surface condition of the grain being processed. During the first or second pass through the machine, pressure was relatively low, reached a maximum after two to three passes with combinations I and II, three to six with combination III and then began to fall. 2. The pitch of the feed screw and the size of the feed gate opening which determine the rate of entry of grain into the whitening chamber, appeared to be the most important factor aff-::cting the degree of radial pressure, quality and quantity of milled rice and the efficiency of the machine. Using a feed screw with a wide pitch (4.8cm), radial pressure was relatively high and head rice recovery ratio \vere quite low. In this case capacity and machine effic?iency were much higher than obtained when using a feed screw with a narrow pitch (2.3cm). Very significant responses in radial pressure, head rice recovery rates and machine capacity were observed with changes in cylinder speed and counter-pressure levels when using the wide pitch feed screw. 3. The characteristics of the screen which surrounds the whitening chamber had an important effect on whitening efficiency. The existence of small protuberances on the original screen resulted in significant increases in both machine capacity and efficiency but without a significant decrease in head rice recovery or development of excessive radial pressure. Further work is required to determine the effects of screen surface conditions and the shape of the cylinderical steel roller on the rate of bran removal, machine efficiency and recovery rates. The size of the slotted perforations 0:1 the screen affects total milled rice recovery. The opening size on the original screen was fabricated to accommodate the round shape of Japonica rice varieties but was not suitable for the more slender Indica type. Milling Indica varieties with this screen resulted in a reduction in total milled rice recovery. 4. An increase in cylinder speed from 380 to 820 rpm produced a positive effect on head rice recovery for all machine combinations at every level of counter-pressure used in the tests. Head rice recovery was considerably lower at 380rpm using a wide screw pitch when compared to the results obtained at speeds from 600 to 820 r.p.m. The effects of cylinder speed On radial pressure, capacity and machine efficiency showed contrasting results, depending on the width of the feed screw pitch. With a narrow feed screw pitch (2.3cm), a direct proportional relationship was observed bet?ween cylinder speed and both radial pressure and machine efficiency. In contrast, using a 4.8 centimeter pitch feed roller produced a series of inverse relationships between the above variables. Based on the results of this study it is recommended when milling Indica type long grain rice varieties that the cylinder speed of the original machine be increased from 500-600 rmp up to a minimum of 800 rpm to obtain a greater abrasive effect between the grain and the screen. The pitch of the feed screw should be also reduced to decr?ease the level of internal radial pressure and to obtain higher machine efficiency and increased quality of milled rice with increased cylinder speeds. Further study on the interaction between cylinder speed and feed screw pitch is recommended. 5. An increase in the counter pressure level produced a negative effect On the head rice recovery with an increase in radial pressure, capacity, and machine efficiency over all combinations and at every level of cylinder speed. 6. Head rice recovery rates were conditioned primarily by the pressure inside the whitening chamber. According to the empirical cha racteristics curve developed in this study, the relationships of head rice recovery ($Y_h$) and machine capacity ($Y_c$/TEX>) to internal radial pressure ($X_p$) followed an inverse quadratic function and a linear function respectively: $$Y_h^\Delta=\frac{1}{{1.4383-0.2951X_p^\ast+0.1425X_p^{\ast\ast}}^2} , (R^2=0.98)$$$$Y_c^\Delta=-305.83+374.37X_p^{\ast\ast}, (R^2=0.88)$$The correlation between capacity and power consumption per unit of brown rice expressed in the following exponential function: $$Y_c^\Delta=1.63Y_c^{-0.7786^\{\ast\ast}, (R^2=0.94)$$These relationships indicate that when radial pressure increases above a certain range (1. 6 to 2.0 kg/$cm^2$ based On the results of the experiment) head ricerecovery decrea?ses in a quadratic relation with a inear increase in capacity but without any decrease in power consump tion per unit of brown rice. On the other hand, if radial pressure is below the range shown above, power consumption increases dramatically with a lin?ear decrease in capacity but without significant increases in head rice recovery. During the operation of a given whitening machine, the optimum radial pressure range or the correct capacity range should be selected by controlling the feed rate and/or counter-pressure keeping in mind the condition of the grain, particulary the hardness. It was observed that the total number of passes is related to radial pessure level, feed rate and counter-pressure level. The higher theradial pressure the fewer num?ber of pass required but with decreased head rice recovery. In particular, when using high feed rates, the total number of passes should be increased to more than three by reducing the counter-pressure level to avoid decreaseases in head rice recovery (less than 65 percent head rice recovery on the basis of brown rice) at every cylinder speed. 7. A rapid rise in grain temperature seemed to have a close relationship with the pressure generated inside the whitening chamber and, subsequently with head rice reco?very rates. The higher the rate of increase, the lower were the resulting head rice recoveries.

Mechanical and Operational Factors Affecting the Efficiency of Rice Polishing Machines (정미기의 능률에 미치는 기계적 요인및 작동조건에 관한 연구)

  • 노상하;최재갑
    • Journal of Biosystems Engineering
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    • v.1 no.1
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    • pp.17-48
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    • 1976
  • In analyzing the operational characteristics of a rice whitening machine, the internal radial pressure of the machine was measured using strain gage equipment. Changes in cylinder and feed screw configurations, screen type, cylinder speed and counter-pressure levels were examined to determine their impact on the quality and quantity of milled rice and the performance of the machine. The results are summarized as follows: 1. The internal radial pressure in the whitening chamber varied with the surface condition of the grain being processed. During the first or second pass through the machine, pressure was relatively low, reached a maximum after two to three passes with combinations I and II, three to six with combination III and then began to fall. 2. The pitch of the feed screw and the size of the feed gate opening which determine the rate of entry of grain into the whitening chamber, appeared to be the most important factor aff-::cting the degree of radial pressure, quality and quantity of milled rice and the efficiency of the machine. Using a feed screw with a wide pitch (4.8cm), radial pressure was relatively high and head rice recovery ratio \vere quite low. In this case capacity and machine effic\ulcorneriency were much higher than obtained when using a feed screw with a narrow pitch (2.3cm). Very significant responses in radial pressure, head rice recovery rates and machine capacity were observed with changes in cylinder speed and counter-pressure levels when using the wide pitch feed screw. 3. The characteristics of the screen which surrounds the whitening chamber had an important effect on whitening efficiency. The existence of small protuberances on the original screen resulted in significant increases in both machine capacity and efficiency but without a significant decrease in head rice recovery or development of excessive radial pressure. Further work is required to determine the effects of screen surface conditions and the shape of the cylinderical steel roller on the rate of bran removal, machine efficiency and recovery rates. The size of the slotted perforations 0:1 the screen affects total milled rice recovery. The opening size on the original screen was fabricated to accommodate the round shape of Japonica rice varieties but was not suitable for the more slender Indica type. Milling Indica varieties with this screen resulted in a reduction in total milled rice recovery. 4. An increase in cylinder speed from 380 to 820 rpm produced a positive effect on head rice recovery for all machine combinations at every level of counter-pressure used in the tests. Head rice recovery was considerably lower at 380rpm using a wide screw pitch when compared to the results obtained at speeds from 600 to 820 r.p.m. The effects of cylinder speed On radial pressure, capacity and machine efficiency showed contrasting results, depending on the width of the feed screw pitch. With a narrow feed screw pitch (2.3cm), a direct proportional relationship was observed bet\ulcornerween cylinder speed and both radial pressure and machine efficiency. In contrast, using a 4.8 centimeter pitch feed roller produced a series of inverse relationships between the above variables. Based on the results of this study it is recommended when milling Indica type long grain rice varieties that the cylinder speed of the original machine be increased from 500-600 rmp up to a minimum of 800 rpm to obtain a greater abrasive effect between the grain and the screen. The pitch of the feed screw should be also reduced to decr\ulcornerease the level of internal radial pressure and to obtain higher machine efficiency and increased quality of milled rice with increased cylinder speeds. Further study on the interaction between cylinder speed and feed screw pitch is recommended. 5. An increase in the counter pressure level produced a negative effect On the head rice recovery with an increase in radial pressure, capacity, and machine efficiency over all combinations and at every level of cylinder speed. 6. Head rice recovery rates were conditioned primarily by the pressure inside the whitening chamber. According to the empirical cha racteristics curve developed in this study, the relationships of head rice recovery ($Y_h$) and machine capacity ($Y_c$/TEX>) to internal radial pressure ($X_p$) followed an inverse quadratic function and a linear function respectively: $$Y_h^\Delta=\frac{1}{{1.4383-0.2951X_p^\ast+0.1425X_p^{\ast\ast}}^2} , (R^2=0.98)$$ $$Y_c^\Delta=-305.83+374.37X_p^{\ast\ast}, (R^2=0.88)$$ The correlation between capacity and power consumption per unit of brown rice expressed in the following exponential function: $$Y_c^\Delta=1.63Y_c^{-0.7786^\{\ast\ast}, (R^2=0.94)$$ These relationships indicate that when radial pressure increases above a certain range (1. 6 to 2.0 kg/$cm^2$ based On the results of the experiment) head ricerecovery decrea\ulcornerses in a quadratic relation with a inear increase in capacity but without any decrease in power consump tion per unit of brown rice. On the other hand, if radial pressure is below the range shown above, power consumption increases dramatically with a lin\ulcornerear decrease in capacity but without significant increases in head rice recovery. During the operation of a given whitening machine, the optimum radial pressure range or the correct capacity range should be selected by controlling the feed rate and/or counter-pressure keeping in mind the condition of the grain, particulary the hardness. It was observed that the total number of passes is related to radial pessure level, feed rate and counter-pressure level. The higher theradial pressure the fewer num\ulcornerber of pass required but with decreased head rice recovery. In particular, when using high feed rates, the total number of passes should be increased to more than three by reducing the counter-pressure level to avoid decreaseases in head rice recovery (less than 65 percent head rice recovery on the basis of brown rice) at every cylinder speed. 7. A rapid rise in grain temperature seemed to have a close relationship with the pressure generated inside the whitening chamber and, subsequently with head rice reco\ulcornervery rates. The higher the rate of increase, the lower were the resulting head rice recoveries.

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A Study on the Various Attributes of E-Sport Influencing Flow and Identification (e-스포츠의 다양한 속성이 유동(flow)과 동일시에 미치는 영향에 관한 연구)

  • Suh, Mun-Shik;Ahn, Jin-Woo;Kim, Eun-Young;Um, Seong-Won
    • Journal of Global Scholars of Marketing Science
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    • v.18 no.1
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    • pp.59-80
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    • 2008
  • Recently, e-sports are growing with potentiality as a new industry with conspicuous profit model. But studies that dealing with e-sports are not enough. Hence, proposes of this paper are both to establish basic model that is for the design of e-sport marketing strategy and to contribute toward future studies which are related to e-sports. Recently, the researches to explain sports-sponsorship through the identification theory have been discovered. Many researches say that somewhat proper identification is a requirement for most sponsors to improve the their images which is essential to sponsorship activity. Consequently, the research for sponsorship associated with identification in the e-sports, not in the physical sports is the core sector of this study. We extracted the variables from online's major characteristics and existing sport sponsorship researches. First, because e-sports mean the tournaments or leagues in the use of online game, the main event of the game is likely to call it online game. Online media's attributes are distinguished from those of offline. Especially, interactivity, anonymity, and expandibility as a e-sport game attributes are able to be mentioned. So, these inherent online attributes are examined on the relationship with flow. Second, in physical sports games, Fisher(1998) revealed that team similarity and team attractivity were positively related to team identification. Wann(1996) said that the result of former game influenced the evaluation of the next game, then in turn has an effect on the identification of team supporters. Considering these results in the e-sports side, e-sports gamer' attractivity, similarity, and match result seem to be important precedent variables of the identification with a gamer. So, these e-sport gamer attributes are examined on the relationship with both flow and identification with a gamer. Csikszentmihalyi(1988) defined the term flow as feeling status for him to be making current positive experience optimally. Hoffman and Novak(1996) also said that if a user experienced the flow he would visit a website without any reward. Therefore flow might be positively associated with user's identification with a gamer. And, Swanson(2003) disclosed that team identification influenced the positive results of sponsorship, which included attitude toward sponsors, sponsor patronage, and satisfaction with sponsors. That is, identification with a gamer expect to be connected with corporation identification significantly. According to the above, we can design the following research model. All variables used in this study(interactivity, anonymity, expandibility, attractivity, similarity, match result, flow, identification with a gamer, and identification with a sponsor) definitely were defined operationally underlying precedent researches. Sample collection was carried out to the person who has an experience to have enjoyed e-sports during June 2006. Much portion of samples is men because much more men than women enjoy e-sports in general. Two-step approach was used to test the hypotheses. First, confirmatory factor analysis was committed to guarantee the validity and reliability of variables. The results showed that all variables had not only intensive and discriminant validity, but also reliability. Then, research model was examined with fully structural equation using LISREL 8.3 version. The fitness of the suggested model mostly was at the acceptable level. Shortly speaking about the results, first of all, in e-sports game attributes, only interactivity which is called a basic feature in online situation affected flow positively. Secondly, in e-sports gamer's attributes, similarity with a gamer and match result influenced flow positively, but there was no significant effect in the relationship between the attractivity of a gamer and flow. And as expected, similarity had an effect on identification with a gamer significantly. But unexpectedly attractivity and match result did not influence identification with a gamer significantly. Just the same as the fact verified in the many precedent researches, flow greatly influenced identification with a gamer, and identification with a gamer continually had an influence on the identification with a sponsor significantly. There are some implications in these results. If the sponsor of e-sports supports the pro-game player who absolutely should have the superior ability to others and is similar to the user enjoying e-sports, many amateur gamers will feel much of the flow and identification with a pro-gamer, and then after all, feel the identification with a sponsor. Such identification with a sponsor leads people enjoying e-sports to have purchasing intention for products produced by the sponsor and to make a positive word-of-mouth for those products or the sponsor. For the future studies, we recommend a few ideas. Based on the results of this study, it is necessary to find new variables relating to the e-sports, which is not mentioned in this study. For this work to be possible, qualitative research seems to be needed to consider the inherent e-sport attributes. Finally, to generalize the results related to e-sports, a wide range of generations not a specific generation should be researched.

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