• Title/Summary/Keyword: Growth condition

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Studies on the Early Development of the Mouse Embryo Transplanted in the Anterior Chamber of the Eye (眼前房내에 이식한 생쥐배의 초기발생에 관한 연구)

  • Cho, Wan Kyoo;Kim, Moon Kyoo
    • The Korean Journal of Zoology
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    • v.15 no.1
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    • pp.25-33
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    • 1972
  • Two-Cell mouse embryos were incubated in the anterior chamber of the rat eye, which has been known as the best place among other animals' for the mouse ovum maturation, in order to observe the capability of their early development. Within 120 hours after incubation, 71.0% of two-cell embryos have developed to the blastocysts in the male rat eye, while only 38.5% in the eye of the same mouse as donated two-cell embryos. Thus, the rat eye chamber provides more favourable environment to the embryos than the mouse itself. The results are consistent with those of the previous studies comparing the maturation of the mouse follicular oocytes in the mouse and the rat eye chamber. Although the aqueous humor which is filled in the anterior chamber of the eye is characterized by its specific properties, being of higher osmolarity, higher concentrations of ascorbic acid, pyruvate and lactate, but lower of proteins and lower temperature than those in blood or lymph serum, The embryos are able to under-take their cleavage as normal as in vivo or in vitro. Concerning with a number of studies in vitro on the development of the mouse embryos which are requiring a very limited condition, the fact that they are able to manage their further development under very different enviroment from our knowledges would provide us a moment to understand their behavior during the early development. The difference of the proportion of the developed blastocysts between in the mouse eye chamber and in the rat can possibly be resulted from the species specific difference in the physicochemical properties between their eye chambers. This assumption is based upon the findings by many investigators who chmpared the nature of the eye chamber of various animals. As a consequence, the rat eye chamber might consist of better properties for the embryonal growth than the mouse eye chamber. The mouse embryos cleaved with a delayed period. In normal development they complete almost the cleavage within 94 hours after fertilization. However, in the present studies, 81.1% of two-cell embryos developed to the blastocysts and the morula in 120 hours in the eye chamber, assumed to be about 154 hours after fertilization. Such delay in development would be caused mainly by the low temperature of the eye chamber. At present we can make two assumptions to explain the capability of the emtryonal development in the eye chambers. One is that the embryos would possess an ability to adapt themselves to the environment which provides unfavourable conditions. The other is that the embryos might remain for a certain duration in the eye chamber, which is filled with a new body fluid produced immediately after the loss of the aqueous humor and the fluid of which becomes similar to blood serum in component. The first assumption is highly reliable since the embryonal cells are mostly at the undifferentiated state and so they probably engage a simple metabolism during their early period. The second assumption is induced by the fact that the rabbit eye chamber produces a plasmoid humor which has mostly similar components to blood serum after loss of aqueous humor through cornea by puncturing. However, the plasmoid humor is substituted by the initial aqueous humor in eight hours. Even though this finding, production of the new fluid, could be applied to the rat eye, it is hardly reliabel that the plasmoid humor remains for such a long period as 120 hours. Consequently, the development of the embryos is more likely due to their adaptability to the new environment during their early developmental stages.

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A Study on Factors Affecting BigData Acceptance Intention of Agricultural Enterprises (농업 관련 기업의 빅데이터 수용 의도에 미치는 영향요인 연구)

  • Ryu, GaHyun;Heo, Chul-Moo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.1
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    • pp.157-175
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    • 2022
  • At this moment, a paradigm shift is taking place across all sectors of society for the transition movements to the digital economy. Various movements are taking place in the global agricultural industry to achieve innovative growth using big data which is a key resource of the 4th industrial revolution. Although the government is making various attempts to promote the use of big data, the movement of the agricultural industry as a key player in the use of big data, is still insufficient. Therefore, in this study, effects of performance expectations, effort expectations, social impact, facilitation conditions, based on the Unified Theory of Acceptance and Use of Technology(UTAUT), and innovation tendencies on the acceptance intention of big data were analyzed using the economic and practical benefits that can be obtained from the use of big data for agricultural-related companies as moderating variables. 333 questionnaires collected from agricultural-related companies were used for empirical analysis. The analysis results using SPSS v22.0 and Process macro v3.4 were found to have a significant positive (+) effect on the intention to accept big data by effort expectations, social impact, facilitation conditions, and innovation tendencies. However, it was found that the effect of performance expectations on acceptance intention was insignificant, with social impact having the greatest influence on acceptance intention and innovation tendency the least. Moderating effects of economic benefit and practical benefit between effort expectation and acceptance intention, moderating effect of practical benefit between social impact and acceptance intention, and moderating effect of economic benefit and practical benefit between facilitation condition and acceptance intention were found to be significant. On the other hand, it was found that economic benefits and practical benefits did not moderate the magnitude of the influence of performance expectations and innovation tendency on acceptance intention. These results suggest the following implications. First, in order to promote the use of big data by companies, the government needs to establish a policy to support the use of big data tailored to companies. Significant results can only be achieved when corporate members form a correct understanding and consensus on the use of big data. Second, it is necessary to establish and implement a platform specialized for agricultural data which can support standardized linkage between diverse agricultural big data, and support for a unified path for data access. Building such a platform will be able to advance the industry by forming an independent cooperative relationship between companies. Finally, the limitations of this study and follow-up tasks are presented.

Analytical Psychology in Psychiatric Clinics (진료현장에서의 분석심리학 : 정신건강의학과 진료실에서 접하는 문제들의 분석심리학적 접근 경험)

  • Sang-Hag Park
    • Sim-seong Yeon-gu
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    • v.35 no.2
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    • pp.85-112
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    • 2020
  • How does analytical psychology help understand patients at general psychiatric clinics? It's necessary to think about how knowledge of analytical psychology can help young psychiatrists who are in training. Patients who come to us bring symptoms(problems). Symptoms can be compared to tickets to a movie theater. Symptoms accompanied by complaints of pain are not only pathological phenomena to be eliminated, but an important pathway to access the patients' inner problems. In terms of seeing the whole, the point of view in analytical psychology is to see the unconscious as well as the consciousness, even the elements the patients do not speak or know of. When determining indications and contra-indications during the initial process of treating a patient, it is more important to acknowledge the therapist's capabilities and limitations than the patient's condition or limitations The approach to complaints of the same symptoms may differ depending on whether the patient is in the first half or the second half of one's life. Analytical psychology is empirical psychology that experiences and it adheres to a phenomenological position that recognizes the phenomenon as true in itself, not logically right or wrong. The analytical psychological view of understanding mental phenomena asks the causal perspective of why the symptoms occurred. At the same time, the therapist, along with the patient, must seek answers to the question of why now and for what purpose. A therapist is a person who experiences the patient's personal development process together. In analytical psychotherapy, the therapist's attitude is more emphasized than the treatment method or technique; it is regarded as of the utmost importance. In this regard, analytical psychology is a practical and useful therapeutic tool, and is a field of study that can be widely used in actual psychiatric clinics. In addition to understanding the patient, it is also the most important discipline for the therapists, especially for the education and growth of those who want to become a treatment tool themselves.

Studies on the Germination Characteristics of Sesame (Sesamum indicum L.) (참깨의 발아특성(發芽特性)에 관(關)한 연구(硏究))

  • Kim, Choong Soo
    • Korean Journal of Agricultural Science
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    • v.10 no.1
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    • pp.28-60
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    • 1983
  • This study was carried out to define the effects of external factors including temperature, moisture, oxygen and light quality on the germination of sesame seeds and to investigate the change of major chemical constituents of seeds during germination. The results obtained are summarized as follows: 1. The average germination ratio was from 95.8% to 97.2% when it was tested every $5^{\circ}C$ intervals from $20^{\circ}C$ to $35^{\circ}C$ and no significant difference in germination ratio was found within $20^{\circ}C$ to $35^{\circ}C$. But the germination ratio dropped rapidly to 32.2% when seeds were germinated at $15^{\circ}C$ and the coefficient of variation become greater(77%) 2. The days required for germination ranged from 1.16 to 1. 64 at the temperatures of $35^{\circ}C$ to $25^{\circ}C$ and they were 3.07 and 10.4 at the temperatures of $20^{\circ}C$ and $15^{\circ}C$, respectively. 3. Considering the germination ratio and days needed, $15^{\circ}C$ was assumed to be the minimum temperature for germination practically and this temperature is recommended for testing low temperature tolerance of seed germination of sesame cultivars. 4. The varieties shown the highest low temperature tolerance were Shirogoma and Turkey. The next varieties shown some degree of low temperature germination were Suweon #29, Naebok and IS 58. The varieties with 70 to 80% of germination ratio were Maepo, Suweon #14, Kimpo, Moondeok, and Haenam. Among the 90 varieties tested, the varieties with comparatively high degree of low temperature tolerance were about 10%, and 70% of the low temperature tolerant varieties were domestic varieties. 5. At $12^{\circ}C$ the Shirogoma was the only variety which showed over 50% of germination ratio, 71.4% of the varieties showed less than 20% of germination ratio. When the temperature was raised to $27^{\circ}C$ 18 days after placement at $12^{\circ}C$ all the varieties showed over 90% of germination ratio within 2days. 6. The amounts of water imbibition needed for seed germination were 0.48 to 0.62 times of the seed dry weight at $25^{\circ}C$ and were significantly different among sesame cultivars. About 63% of water required for germination was imbibed in 2 hours after placement of seeds under the germination condition. 7. Under saturated moisture condition the average germination ratio was 0.42%. In the soil of which water potential was -0.4bar 64.8% of the seeds germinated and the most adequate soil water potential for sesame seed germination was about -0.4 to -5.5 bar. The germination ratio decreased as the soil water potential declined below -5.5 bar. 8. Six out of 10 varieties were not influenced by 5% of oxygen in air germination chamber, while varieties such as Yecheon, PI 158073, IS 103 and Euisangcheon showed 64 to 91% of germination under the 5% oxygen content. Under anaerobic condition, cotyledones were not emerged but only hypocotyl was emerged and elongated. The germination ratio of IS 103 decreased significantly under anaerobic condition. 9. When the seeds were dried for 24 hours after 12 hours imbibition of water, the seeds of Cheongsong did not lose their germination ability and 27.5% was germinated but Suweon #9 and Early Russian failed to germinate. However, the germination ratio of IS 103 decreased when the seed were dried 24 hours after 4 hours imbibition of water and the germination ability of IS 103 was maintained even though the seeds were dried for 24 hours after 24 hours imbibition of water. 10. During germination, sugar content of sesame seed increased rapidly and activity of ${\alpha}$-amylase increased gradually while starch content decreased significantly. The rates of increase in sugar content and enzyme activity and decrease in starch content were significantly lower at $15^{\circ}C$ compared with those at $25^{\circ}C$. 11. During germination of sesame seeds, lipid content in the seeds dropped rapidly and the activity of alkaline lipase increased significantly at early stage of germination. The rate of decrease in lipid content and increase in emzyme activity was lower at $15^{\circ}C$ than at $25^{\circ}C$. 12. Four out of 6 varieties were not affected in germination by light wave length. But Suweon #8 was inhibited in germination by 600-650nm. and IS 103 by 600 to 650nm and 500 to 550nm of light wave length. Suweon #8 showed high germination ratio under 650 to 760 nm and 500 to 560nm, and IS 103 under 400 to 470nm and complete darkness. 13. The germination ratios increased significantly in the seeds of which 1000 grain weight is heavier. When the seeds were placed at soil 4cm deep, Cheongsong and Early Russian failed to emerge their cotyledones, but Suweon #9 and IS 103 showed 32.5 and 50% cotyledone emergence, respectively. The extracts from sesame plant and soil where the sesame was cultivated previously did not affect in the-germination of sesame seeds. 14. The covering by black or transparent polyethylene films increased germination ratio compared with uncovered seeds. The covering was effective in shortening the days needed for germination and in improving the early seedling growth, number of capsules per plant and grain yield. Difference was not so seizable between the two polyethylene films but the transparent film appeared somewhat more effective than the black one. 15. Simcheon, Cheongsong. Suweon #9. PI 158073 and IS 103 showed lower rate of water absorbtion by seed during germination and Suweon #8, Suweon #26, Orotall and Euisangcheon showed high increase in seed weight after water absorbtion by seed.

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Ecological Studies on the Transition of Sheath Blight of Rice in Korea (한국(韓國)에서의 벼 잎집무늬마름병 발생변동(發生變動)에 관(關)한 생태학적(生態學的) 연구(硏究))

  • Yu, Seung-hun
    • Korean Journal of Agricultural Science
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    • v.4 no.2
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    • pp.283-316
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    • 1977
  • In an attempt to obtain a basic information to develop an effective integrated system of controlling sheath blight of rice in Korea, the transition of this disease, the variation of cultural characters and pathogenicity of the pathogen, environmental conditions affecting the disease outbreak and varietal resistance have been investigated. 1. Rice sheath blight which has been minor disease in the past was widely spread, especially since 1971. This disease has promptly spread all over the country and infected 65.2% of total rice growing area in 1976. Various factors are considered to be related to such transition of this disease. Above all, increace of application of nitrogenous fertilizer, early season and earlier cultivation of rice, introduction of more susceptible "Tongil" varieties etc. must be important factors influencing the outbreak of this disease. 2. Great variations in cultural characteristics-such as mycelial growth rate, color of the medium, amount of the aerial mycelium, shape and color of the sclerotia- and in the pathogenicity of isolates of the pathogen, Thanatephorus cucumeris Dank were observed. The optimum temperature for mycelial growth also varied with isolates, from $25^{\circ}C$ to $30^{\circ}C$. There were not necessarily any correlation between curtural characteristics and pathogenicity of isolates of Thanatephorus cucumens. 3. Mycelial grow th of isolates of Thanatephorus cucumens on the PDA medium were correlated with the air temperatures of the region where the isolates were collected. The isolates from the regions with high temperature grew well on PDA medium at $35^{\circ}C$ than those from the region with low temperature, on the other hand, the isolates from the regions with the low temperature grew well on the same medium at $12^{\circ}C$ than those from the regions with high temperature. 4. Pectin polygalacturonase (PG) and cellulase (Cx) were most active on the 3rd day after inoculation on the leaves of rice plant with Thanatephorus cucumeris, whereas pectin methylestrase (PE) was most active on the 4th day after inoculation. Relationship between the activities of PE of isolates and the strength of pathogenicity of isolates was obtained, but PG and cellulase activities were not correlated with pathogenicity of isolates. 5. The tolerence of sclerotia from in-vitro culture to low temperature varied with their water content, the dried cultural sclerotia were more tolerent than wet ones, Dried cultural sclerotia maintained almost 100% germinability for 45 days at $-20^{\circ}C$, whereas wet sclerotia lost viability at $-5^{\circ}C$. The germination ratio of the sclerotia after overwintering changed from 18% to 70% according to the water content of the test paddy fields and the ratio was low in wet paddy condition. 6. To investigate the host range of this fungi in and near paddy field, 17 weeds were inoculated with fungi. The lesions of sheath blight disease was obserbed on Sagittaria trifolia L., Echinochloa crusgalli P. Beauv., Monochoria vaginal is Presl, Polygonum Hydropiper L., Eclipta prostrata L., Digitaria sanguinalis Scapoli. 7. When the level of nitrogen applied was doubled over standard level, total nitrogen content in rice sheath increased, ami when silicate was applied, starch content in rice sheath decreased, inducing the rice plants more susceptible to sheath blight disease. Increased dressing of potash ferilizer reduced the incidence of sheat blight disease. 8. The percentage of infected stems in the early period increased more in the narrow hill plot than in the wide hill plot, but in the late period this tendency was inversed; the percentage of infected stems as well as severity in the wide hill plot increased more compared to the narrow hill plot, and the disease severity in the one plant per hill plot was also low. The number of stems in the wide hill plot was more than the number of stems in the narrow hill plot. This indicates that the microclimate, such as the relative humidity, in the narrow hill plot was more favorable for the development of this disease. 9. There was a high negative correlation between the disease severity of varieties to the sheath blight and the maturity of the varieties, that is, the early varieties were more susceptible than the late ones, and much-tillering varieties usually showed more infection than less tillering varieties. 10. No relationship was obtained between the percentage of infected stems in the early period and the severity after heading, whereas a distinct relationship was obtained between former and latter after Aug. 10.

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Studies on the Pulping Characteristics of Larchwood (Larix leptolepis Gordon) by Alkaline Process with Additives (첨가제(添加劑) 알칼리 법(法)에 의한 일본 잎갈 나무의 펄프화(化) 특성(特性)에 관(關)한 연구(硏究))

  • Lim, Kie-Pyo;Shin, Dong-Sho
    • Journal of the Korean Wood Science and Technology
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    • v.7 no.2
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    • pp.3-30
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    • 1979
  • Larch ($\underline{Larix}$ $\underline{leptolepis}$ GORDON), one of the major afforestation species in Korea in view of its growing stock and rate of growth, is not favored as a raw material for pulp due to its low yield of pulp and difficulties with bleaching arising from the high content of extractives in wood, and the high heartwood ratio and the active phenolics, respectively. The purpose of this study is to investigate the characteristics of firstly pulping with various additives of cellulose protector for the yield of pulp, and secondly bleaching with oxygen for chlotination-alkali extraction of five stage-sequence to reduce chlorine compounds in bleaching effluents. The kraft cooking liquor for five age groups of larchwood was 18 percent active alkali with 25 percent sulfidity and 5 : 1 liquor-to-wood ratio, and each soda liquor for sap-and heart-wood of the 15-year-old larchwood was 18 percent alkali having one of the following cellulose protectors as the additive; magnesium sulfate ($MgSO_4$, 2.5%), zinc sulfate ($ZnSO_4$, 2.5%), aluminium sulfate ($Al_2(SO_4)_3$, 2.5%), potasium iodide (KI, 2.5%), hydroquinone (HQ, 2.5%), anthraquinone (AQ, 0.1%) and ethylene diamine (EDA, 2.5%). Then each anthraquinone-soda liquor for the determination of suitable cooking condition was the active alkali level of 15, 17 and 19 percent with 1.0, 0.5 and 0.1 percent anthraquinone, respectively. The cooking procedure for the pulps was scheduled to heat to 170$^{\circ}C$ in 90 minutes and to cook 90 minutes at the maximum temperature. The anthraquinone-soda pulps from both heartwood and sapwood of 15-year-old larchwood prepared with 0.5 percent anthraquinone and 18 percent active alkali were bleached in a four-stage sequency of OCED. (O: oxygen bleaching, D: chlorine dioxide bleaching and E: alkali extraction). In the first stage oxygen in atmospheric pressure was applied to a 30 percent consistency of pulp with 0.1 percent magnesium oxide (MgO) and 3, 6, and 9 percent sodium hydroxide on oven dry base, and the bleached results were compared pulps bleached under the conventional CEDED (C: chlorination). The results in the study were summarized as follows: 1. The screened yield of larch kraft pulp did not differ from particular ages to age group, but heartwood ratio, basic density, fiber length and water-extractives contents of wood and the tear factor of the pulp increased with increasing the tree age. The total yield of the pulp decreased. 2. The yield of soda pulp with various chemicals for cellulose protection of the 15-year-old larchwood increased slightly more than that of pure soda pulp and was slightly lower than that of kraft pulp. The influence of cellulose protectors was similar to the yield of pulps from both sapwood and heartwood. The effective protectors among seven additives were KI, $MgSO_4$ and AQ, for which the yields of screened pulp was as high as that of kraft pulp. Considering the additive level of protector, the AQ was the most effective in improving the yield and the quality of pulp. 3. When the amount of AQ increased in soda cooking, the yield and the quality of the pulp increased but rejects in total yield increased with decreasing the amount of active alkali from 19 to 15 percent. The best proportion of the AQ seemed to be 0.5 percent at 17 percent active alkali in anthraquinone-soda pulping. 4. On the bleaching of the AQ-soda pulp at 30 percent consistency with oxygen of atomospheric pressure in the first stage of the ODED sequence, the more caustic soda added, the brighter bleached pulp was obtained, but more lignin-selective bleaching reagent in proportion to the oxygen was necessary to maintain the increased yield with the addition of anthraquinone. 5. In conclusion, the suitable pulping condition for larchwood to improve the yield and quality of the chemical pulp to the level for kraft pulp from conventional process seemed to be. A) the selection of young larchwood to prevent decreasing in yield and quality due to the accumulation extractives in old wood, B) the application of 0.5 percent anthraquinone to the conventional soda cooking of 18 percent active alkali, and followed, C) the bleaching of oxygen in atmospheric pressure on high consistency (30%) with 0.1 percent magnesium oxide in the first stage of the ODED sequence to reduce the content of chlorine compounds in effluent.

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Methodology for Identifying Issues of User Reviews from the Perspective of Evaluation Criteria: Focus on a Hotel Information Site (사용자 리뷰의 평가기준 별 이슈 식별 방법론: 호텔 리뷰 사이트를 중심으로)

  • Byun, Sungho;Lee, Donghoon;Kim, Namgyu
    • Journal of Intelligence and Information Systems
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    • v.22 no.3
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    • pp.23-43
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    • 2016
  • As a result of the growth of Internet data and the rapid development of Internet technology, "big data" analysis has gained prominence as a major approach for evaluating and mining enormous data for various purposes. Especially, in recent years, people tend to share their experiences related to their leisure activities while also reviewing others' inputs concerning their activities. Therefore, by referring to others' leisure activity-related experiences, they are able to gather information that might guarantee them better leisure activities in the future. This phenomenon has appeared throughout many aspects of leisure activities such as movies, traveling, accommodation, and dining. Apart from blogs and social networking sites, many other websites provide a wealth of information related to leisure activities. Most of these websites provide information of each product in various formats depending on different purposes and perspectives. Generally, most of the websites provide the average ratings and detailed reviews of users who actually used products/services, and these ratings and reviews can actually support the decision of potential customers in purchasing the same products/services. However, the existing websites offering information on leisure activities only provide the rating and review based on one stage of a set of evaluation criteria. Therefore, to identify the main issue for each evaluation criterion as well as the characteristics of specific elements comprising each criterion, users have to read a large number of reviews. In particular, as most of the users search for the characteristics of the detailed elements for one or more specific evaluation criteria based on their priorities, they must spend a great deal of time and effort to obtain the desired information by reading more reviews and understanding the contents of such reviews. Although some websites break down the evaluation criteria and direct the user to input their reviews according to different levels of criteria, there exist excessive amounts of input sections that make the whole process inconvenient for the users. Further, problems may arise if a user does not follow the instructions for the input sections or fill in the wrong input sections. Finally, treating the evaluation criteria breakdown as a realistic alternative is difficult, because identifying all the detailed criteria for each evaluation criterion is a challenging task. For example, if a review about a certain hotel has been written, people tend to only write one-stage reviews for various components such as accessibility, rooms, services, or food. These might be the reviews for most frequently asked questions, such as distance between the nearest subway station or condition of the bathroom, but they still lack detailed information for these questions. In addition, in case a breakdown of the evaluation criteria was provided along with various input sections, the user might only fill in the evaluation criterion for accessibility or fill in the wrong information such as information regarding rooms in the evaluation criteria for accessibility. Thus, the reliability of the segmented review will be greatly reduced. In this study, we propose an approach to overcome the limitations of the existing leisure activity information websites, namely, (1) the reliability of reviews for each evaluation criteria and (2) the difficulty of identifying the detailed contents that make up the evaluation criteria. In our proposed methodology, we first identify the review content and construct the lexicon for each evaluation criterion by using the terms that are frequently used for each criterion. Next, the sentences in the review documents containing the terms in the constructed lexicon are decomposed into review units, which are then reconstructed by using the evaluation criteria. Finally, the issues of the constructed review units by evaluation criteria are derived and the summary results are provided. Apart from the derived issues, the review units are also provided. Therefore, this approach aims to help users save on time and effort, because they will only be reading the relevant information they need for each evaluation criterion rather than go through the entire text of review. Our proposed methodology is based on the topic modeling, which is being actively used in text analysis. The review is decomposed into sentence units rather than considering the whole review as a document unit. After being decomposed into individual review units, the review units are reorganized according to each evaluation criterion and then used in the subsequent analysis. This work largely differs from the existing topic modeling-based studies. In this paper, we collected 423 reviews from hotel information websites and decomposed these reviews into 4,860 review units. We then reorganized the review units according to six different evaluation criteria. By applying these review units in our methodology, the analysis results can be introduced, and the utility of proposed methodology can be demonstrated.

No-tillage Agriculture of Korean-Type on Recycled Ridge I. Changes in Physical Properties : Soil Crack, Penetration Resistance, Drainage, and Capacity to Retain Water at Plastic Film Greenhouse Soil by Different Tillage System (두둑을 재활용한 한국형 무경운 농업 I. 경운방법에 따른 시설재배 토양의 물리적 특성: 균열, 관입저항, 배수, 보수력 변화)

  • Yang, Seung-Koo;Jung, Woo-Jin
    • Korean Journal of Organic Agriculture
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    • v.24 no.4
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    • pp.699-717
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    • 2016
  • This study was carried out to investigate the effect of no-tillage on sequential cropping supported from recycling of first crop ridge on the growth of pepper plant and physical properties of soil under green house condition. 1. Degree of crack on soil by tillage and no-tillage Soil cracks found in ridge and not found in row. At five months of tillage, crack number and crack length in length ridge were 3 and 37~51 cm in tillage. Maximum width and maximum depth in length ridge were 30 mm and 15.3cm in tillage. Crack number and crack length in width ridge were 7.5 and 7~28 cm in tillage. Maximum width and maximum depth in width ridge were 29 mm and 15.3 cm in tillage. At a year of no-tillage, crack number and crack length in length ridge were 1.0 and 140~200 cm in tillage. Maximum width and maximum depth in length ridge were 18 mm and 30 cm in a year of no-tillage. Crack number and crack length in width ridge were 11 and 6~22 cm in a year of no-tillage. Maximum width and maximum depth in width ridge were 22 mm and 18.5 cm in a year of no-tillage. Soil crack was not found at 2 years of no-tillage in sandy Jungdong series (jd) soil. Soil crack was found at 7 years of no-tillage in clayish Jisan series (ji) soil. 2. Penetration resistance on soil Penetration resistance was increased significantly at no-tillage in Jungdong series (jd). Depth of cultivation layer was extended at no-tillage soil compared with tillage soil. Penetration resistance of plow pan was decreased at 1 year of no-tillage compared with than tillage soil. Penetration resistance was linearly increased with increasing soil depth at tillage in Jisan series (ji). Penetration resistance on top soil was remarkably increased and then maintained continuously at no-tillage soil. 3. Drainage and moisture content of soil Moisture content of ridge in top soil was not significant difference at both tillage and no-tillage. Moisture content of ridge in 20 cm soil was 14% at no-tillage soil and 25% at tillage soil. 4. Change of capacity to retain water in soil Capacity to retain water in top soil was not significant difference at 1 bar both tillage and no-tillage. Capacity to retain water in soil was slightly higher tendency in 1 year and 2 years of no-tillage soil than tillage soil. Capacity to retain water in soil was increased at 15 bar both tillage and no-tillage. Capacity to retain water in subsoil was slightly higher tendency at 1 bar and 3 bar in 2 years of no-tillage than tillage soil and a year of no-tillage soil.

Future Changes in Global Terrestrial Carbon Cycle under RCP Scenarios (RCP 시나리오에 따른 미래 전지구 육상탄소순환 변화 전망)

  • Lee, Cheol;Boo, Kyung-On;Hong, Jinkyu;Seong, Hyunmin;Heo, Tae-kyung;Seol, Kyung-Hee;Lee, Johan;Cho, ChunHo
    • Atmosphere
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    • v.24 no.3
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    • pp.303-315
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    • 2014
  • Terrestrial ecosystem plays the important role as carbon sink in the global carbon cycle. Understanding of interactions of terrestrial carbon cycle with climate is important for better prediction of future climate change. In this paper, terrestrial carbon cycle is investigated by Hadley Centre Global Environmental Model, version 2, Carbon Cycle (HadGEM2-CC) that considers vegetation dynamics and an interactive carbon cycle with climate. The simulation for future projection is based on the three (8.5/4.5/2.6) representative concentration pathways (RCPs) from 2006 to 2100 and compared with historical land carbon uptake from 1979 to 2005. Projected changes in ecological features such as production, respiration, net ecosystem exchange and climate condition show similar pattern in three RCPs, while the response amplitude in each RCPs are different. For all RCP scenarios, temperature and precipitation increase with rising of the atmospheric $CO_2$. Such climate conditions are favorable for vegetation growth and extension, causing future increase of terrestrial carbon uptakes in all RCPs. At the end of 21st century, the global average of gross and net primary productions and respiration increase in all RCPs and terrestrial ecosystem remains as carbon sink. This enhancement of land $CO_2$ uptake is attributed by the vegetated area expansion, increasing LAI, and early onset of growing season. After mid-21st century, temperature rising leads to excessive increase of soil respiration than net primary production and thus the terrestrial carbon uptake begins to fall since that time. Regionally the NEE average value of East-Asia ($90^{\circ}E-140^{\circ}E$, $20^{\circ}N{\sim}60^{\circ}N$) area is bigger than that of the same latitude band. In the end-$21^{st}$ the NEE mean values in East-Asia area are $-2.09PgC\;yr^{-1}$, $-1.12PgC\;yr^{-1}$, $-0.47PgC\;yr^{-1}$ and zonal mean NEEs of the same latitude region are $-1.12PgC\;yr^{-1}$, $-0.55PgC\;yr^{-1}$, $-0.17PgC\;yr^{-1}$ for RCP 8.5, 4.5, 2.6.

Developmental Plans and Research on Private Security in Korea (한국 민간경비 실태 및 발전방안)

  • Kim, Tea-Hwan;Park, Ok-Cheol
    • Korean Security Journal
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    • no.9
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    • pp.69-98
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    • 2005
  • The security industry for civilians (Private Security), was first introduced to Korea via the US army's security system in the early 1960's. Shortly after then, official police laws were enforced in 1973, and private security finally started to develop with the passing of the 'service security industry' law in 1976. Korea's Private Security industry grew rapidly in the 1980's with the support of foreign funds and products, and now there are thought to be approximately 2000 private security enterprises currently running in Korea. However, nowadays the majority of these enterprises are experiencing difficulties such as lack of funds, insufficient management, and lack of control over employees, as a result, it seems difficult for some enterprises to avoid the low production output and bankruptcy. As a result of this these enterprises often settle these matters illegally, such as excessive dumping or avoiding problems by hiring inappropriate employees who don't have the right skills or qualifications for the jobs. The main problem with the establishment of this kind of security service is that it is so easy to make inroads into this private service market. All these hindering factors inhibit the market growth and impede qualitative development. Based on these main reasons, I researched this area, and will analyze and criticize the present condition of Korea's private security. I will present a possible development plan for the private security of Korea by referring to cases from the US and Japan. My method of researching was to investigate any related documentary records and articles and to interview people for necessary evidence. The theoretical study, involves investigation books and dissertations which are published from inside and outside of the country, and studying the complete collection of laws and regulations, internet data, various study reports, and the documentary records and the statistical data of many institutions such as the National Police Office, judicial training institute, and the enterprises of private security. Also, in addition, the contents of professionals who are in charge of practical affairs on the spot in order to overcomes the critical points of documentary records when investigating dissertation. I tried to get a firm grasp of the problems and difficulties which people in these work enterprises experience, this I thought would be most effective by interviewing the workers, for example: how they feel in the work places and what are the elements which inpede development? And I also interviewed policemen who are in charge of supervising the private escort enterprises, in an effort to figure out the problems and differences in opinion between domestic private security service and the police. From this investigation and research I will try to pin point the major problems of the private security and present a developmental plan. Firstly-Companies should unify the private police law and private security service law. Secondly-It is essential to introduce the 'specialty certificate' system for the quality improvement of private security service. Thirdly-must open up a new private security market by improving old system. Fourth-must build up the competitive power of the security service enterprises which is based on an efficient management. Fifth-needs special marketing strategy to hold customers Sixth-needs positive research based on theoretical studies. Seventh-needs the consistent and even training according to effective market demand. Eighth-Must maintain interrelationship with the police department. Ninth-must reinforce the system of Korean private security service association. Tenth-must establish private security laboratory. Based on these suggestions there should be improvement of private security service.

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