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The Effect of Common Features on Consumer Preference for a No-Choice Option: The Moderating Role of Regulatory Focus (재몰유선택적정황하공동특성대우고객희호적영향(在没有选择的情况下共同特性对于顾客喜好的影响): 조절초점적조절작용(调节焦点的调节作用))

  • Park, Jong-Chul;Kim, Kyung-Jin
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.1
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    • pp.89-97
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    • 2010
  • This study researches the effects of common features on a no-choice option with respect to regulatory focus theory. The primary interest is in three factors and their interrelationship: common features, no-choice option, and regulatory focus. Prior studies have compiled vast body of research in these areas. First, the "common features effect" has been observed bymany noted marketing researchers. Tversky (1972) proposed the seminal theory, the EBA model: elimination by aspect. According to this theory, consumers are prone to focus only on unique features during comparison processing, thereby dismissing any common features as redundant information. Recently, however, more provocative ideas have attacked the EBA model by asserting that common features really do affect consumer judgment. Chernev (1997) first reported that adding common features mitigates the choice gap because of the increasing perception of similarity among alternatives. Later, however, Chernev (2001) published a critically developed study against his prior perspective with the proposition that common features may be a cognitive load to consumers, and thus consumers are possible that they are prone to prefer the heuristic processing to the systematic processing. This tends to bring one question to the forefront: Do "common features" affect consumer choice? If so, what are the concrete effects? This study tries to answer the question with respect to the "no-choice" option and regulatory focus. Second, some researchers hold that the no-choice option is another best alternative of consumers, who are likely to avoid having to choose in the context of knotty trade-off settings or mental conflicts. Hope for the future also may increase the no-choice option in the context of optimism or the expectancy of a more satisfactory alternative appearing later. Other issues reported in this domain are time pressure, consumer confidence, and alternative numbers (Dhar and Nowlis 1999; Lin and Wu 2005; Zakay and Tsal 1993). This study casts the no-choice option in yet another perspective: the interactive effects between common features and regulatory focus. Third, "regulatory focus theory" is a very popular theme in recent marketing research. It suggests that consumers have two focal goals facing each other: promotion vs. prevention. A promotion focus deals with the concepts of hope, inspiration, achievement, or gain, whereas prevention focus involves duty, responsibility, safety, or loss-aversion. Thus, while consumers with a promotion focus tend to take risks for gain, the same does not hold true for a prevention focus. Regulatory focus theory predicts consumers' emotions, creativity, attitudes, memory, performance, and judgment, as documented in a vast field of marketing and psychology articles. The perspective of the current study in exploring consumer choice and common features is a somewhat creative viewpoint in the area of regulatory focus. These reviews inspire this study of the interaction possibility between regulatory focus and common features with a no-choice option. Specifically, adding common features rather than omitting them may increase the no-choice option ratio in the choice setting only to prevention-focused consumers, but vice versa to promotion-focused consumers. The reasoning is that when prevention-focused consumers come in contact with common features, they may perceive higher similarity among the alternatives. This conflict among similar options would increase the no-choice ratio. Promotion-focused consumers, however, are possible that they perceive common features as a cue of confirmation bias. And thus their confirmation processing would make their prior preference more robust, then the no-choice ratio may shrink. This logic is verified in two experiments. The first is a $2{\times}2$ between-subject design (whether common features or not X regulatory focus) using a digital cameras as the relevant stimulus-a product very familiar to young subjects. Specifically, the regulatory focus variable is median split through a measure of eleven items. Common features included zoom, weight, memory, and battery, whereas the other two attributes (pixel and price) were unique features. Results supported our hypothesis that adding common features enhanced the no-choice ratio only to prevention-focus consumers, not to those with a promotion focus. These results confirm our hypothesis - the interactive effects between a regulatory focus and the common features. Prior research had suggested that including common features had a effect on consumer choice, but this study shows that common features affect choice by consumer segmentation. The second experiment was used to replicate the results of the first experiment. This experimental study is equal to the prior except only two - priming manipulation and another stimulus. For the promotion focus condition, subjects had to write an essay using words such as profit, inspiration, pleasure, achievement, development, hedonic, change, pursuit, etc. For prevention, however, they had to use the words persistence, safety, protection, aversion, loss, responsibility, stability etc. The room for rent had common features (sunshine, facility, ventilation) and unique features (distance time and building state). These attributes implied various levels and valence for replication of the prior experiment. Our hypothesis was supported repeatedly in the results, and the interaction effects were significant between regulatory focus and common features. Thus, these studies showed the dual effects of common features on consumer choice for a no-choice option. Adding common features may enhance or mitigate no-choice, contradictory as it may sound. Under a prevention focus, adding common features is likely to enhance the no-choice ratio because of increasing mental conflict; under the promotion focus, it is prone to shrink the ratio perhaps because of a "confirmation bias." The research has practical and theoretical implications for marketers, who may need to consider common features carefully in a practical display context according to consumer segmentation (i.e., promotion vs. prevention focus.) Theoretically, the results suggest some meaningful moderator variable between common features and no-choice in that the effect on no-choice option is partly dependent on a regulatory focus. This variable corresponds not only to a chronic perspective but also a situational perspective in our hypothesis domain. Finally, in light of some shortcomings in the research, such as overlooked attribute importance, low ratio of no-choice, or the external validity issue, we hope it influences future studies to explore the little-known world of the "no-choice option."

The Effect of PL Leadership and Characteristics of Project on Project Participants' Satisfaction and Performance (PL 리더십 성향과 프로젝트 특성요인이 프로젝트 참여 만족 및 성과에 미치는 영향)

  • Yang, Hee-Dong;Kim, Myung-Jin;Kang, So-Ra
    • Asia pacific journal of information systems
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    • v.20 no.4
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    • pp.53-79
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    • 2010
  • The study was originated from recognition that project participants' satisfaction should be Improved to raise project performance and to make progress of a successful project since the above dissatisfaction was operated as a danger factor of the project. The study selected one large-scale sample project and attempted measuring characteristics of the project, participants' satisfaction and project performance with the whole project participants. The study analyzed correlations between individual level (team members) and group level (development team), and examined what effect a sub project manager under complicated hierarchical organization of the large-scale project, namely PL (project leader)'s leadership style had on each individual project participant's satisfaction and what effect project uncertainty in organization/technology environment had on project participants' satisfaction and project performance. The study verified that development team (group) had an effect on team member (individual)-level project participants' satisfaction by disclosing that there was a significant dispersion among groups within project participants' satisfaction by each individual. It is analyzed that it is necessary to make improvement through approach by each pertinent team to raise individual-level project participants' satisfaction. The study also verified PL's ideal leadership under strict methodology and hierarchical control of the large-scale project. Based on the verification of the hypotheses, the results of the analysis were produced as follows. First, the development team affects the satisfaction level that an individual has when he/she participates in a project. This suggests that the satisfaction with project participation should be improved at the team level. In addition, the project management style and leadership orientation of the manager of a sub project who is mostly affected by the team proved to have a direct influence on the satisfaction with project participation and project performances. Second, both the performance-oriented leadership and the relationship-oriented leadership of the PL of the development team were verified to have a significant effect on the satisfaction of the team members associated with project participation. In other words, when the team members recognize that the PL of the development team shows both the performance-oriented leadership and the relationship-oriented leadership, their satisfaction with project participation increases accordingly. Third, it was verified that the uncertainty of the organizational environment significantly affects the satisfaction level when the PL of the development team exerts a relationship-oriented and performance-oriented leadership. The higher the uncertainty of the organizational environment is, the more the satisfaction with project participation decreases whereas the relationship-oriented leadership has a more positive effect on the satisfaction than the performance-oriented leadership style. Fourth, when the PL of the development team exerts the relationship-related and performance-related leadership, the uncertainty of the technological environment has a significant influence on the satisfaction level. The higher the uncertainty of the technological environment is, the more the satisfaction with project participation decreases whereas the performance-oriented leadership has a more positive effect on the satisfaction than the relationship-oriented leadership style. The result of the research on the uncertainty of the project environment suggests that when the development team leader exerts a relationship-oriented and performance-oriented leadership style, the uncertainty of the organizational environment has a significant effect on the satisfaction with project participation; the higher the uncertainty of the organizational environment, the more the satisfaction level decreases, and the relationship-oriented leadership style affects the satisfaction level more positively than the performance-oriented leadership style. In addition, when the development team leader displays a relationship-oriented and performance-oriented leadership style, the uncertainty of the technological environment has a significant effect on the satisfaction with project participation; the higher the uncertainty of the technological environment. the more the satisfaction level decreases. The performance-oriented leadership style as well affects the satisfaction level more positively than the relationship-oriented leadership style. Based on the above results, the research provides the following implications when handling multiple concurrent projects. First, the satisfaction with the participation in the multiple concurrent projects needs to be enhanced at the team (group) level. Second. the manager of the project team, particularly the middle managers should have both a performance-oriented and relationship (task and human)-oriented attitude and exert a consolidated leadership in order to improve the satisfaction of team members with project participation and their performances. Third, as the uncertainty factor of the technological and organizational environment among the characteristics factors of the project has room for methodological improvement depending on one's effort even though there are some complications, we need to continuously prevent and control the risks resulting from the uncertainties of the technological and organizational environment of the project in order to enhance the satisfaction of project participation and project performances. Fourth, the performance (task)-oriented leadership is required when there is uncertainty in a technological environment while the relationship (human)-oriented leadership is required when there is uncertainty in an organizational environment. This research has the following limitations. First, this research intended to select one large-sized sample project and measure the project characteristics, the satisfaction of all the participants associated with project participation, and their performances. Therefore, it is inappropriate to generalize and apply the result of this result onto other numerous projects. Second, as this case study entailed a survey to measure the characteristics factors and performance of the project, since the result value was based on the perception of project team members, the data may have insufficient objectivity. Third, though this research targeted on all the project participants, some development teams did not provide sufficient data and questionnaires were collected from some specific development teams among the 23 development teams, causing a significant deviation in the response rate among the development teams. Therefore, we need to continuously conduct the follow-up researches making comparisons among the multiple projects, and centering on the characteristics factors of the project and its satisfaction level.

A STUDY ON THE TEMPERATURE CHANGES OF BONE TISSUES DURING IMPLANT SITE PREPARATION (임플랜트 식립부위 형성시 골조직의 온도변화에 관한 연구)

  • Kim Pyung-Il;Kim Yung-Soo;Jang Kyung-Soo;Kim Chang-Whe
    • The Journal of Korean Academy of Prosthodontics
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    • v.40 no.1
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    • pp.1-17
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    • 2002
  • The purpose of this study is to examine the possibility of thermal injury to bone tissues during an implant site preparation under the same condition as a typical clinical practice of $Br{\aa}nemark$ implant system. All the burs for $Br{\aa}nemark$ implant system were studied except the round bur The experiments involved 880 drilling cases : 50 cases for each of the 5 steps of NP, 5 steps of RP, and 7 steps of WP, all including srew tap, and 30 cases of 2mm twist drill. For precision drilling, a precision handpiece restraining system was developed (Eungyong Machinery Co., Korea). The system kept the drill parallel to the drilling path and allowed horizontal adjustment of the drill with as little as $1{\mu}m$ increment. The thermocouple insertion hole. that is 0.9mm in diameter and 8mm in depth, was prepared 0.2mm away from the tapping bur the last drilling step. The temperatures due to countersink, pilot drill, and other drills were measured at the surface of the bone, at the depths of 4mm and 8mm respectively. Countersink drilling temperature was measured by attaching the tip of a thermocouple at the rim of the countersink. To assure temperature measurement at the desired depths, 'bent-thermocouples' with their tips of 4 and 8mm bent at $120^{\circ}$ were used. The profiles of temperature variation were recorded continuously at one second interval using a thermometer with memory function (Fluke Co. U.S.A.) and 0.7mm thermocouples (Omega Co., U.S.A.). To simulate typical clinical conditions, 35mm square samples of bovine scapular bone were utilized. The samples were approximately 20mm thick with the cortical thickness on the drilling side ranging from 1 to 2mm. A sample was placed in a container of saline solution so that its lower half is submerged into the solution and the upper half exposed to the room air, which averaged $24.9^{\circ}C$. The temperature of the saline solution was maintained at $36.5^{\circ}C$ using an electric heater (J. O Tech Co., Korea). This experimental condition was similar to that of a patient s opened mouth. The study revealed that a 2mm twist drill required greatest attention. As a guide drill, a twist drill is required to bore through a 'virgin bone,' rather than merely enlarging an already drilled hole as is the case with other drills. This typically generates greater amount of heat. Furthermore, one tends to apply a greater pressure to overcome drilling difficulty, thus producing even greater amount heat. 150 experiments were conducted for 2mm twist drill. For 140 cases, drill pressure of 750g was sufficient, and 10 cases required additional 500 or 100g of drilling pressure. In case of the former. 3 of the 140 cases produced the temperature greater than $47^{\circ}C$, the threshold temperature of degeneration of bone tissue (1983. Eriksson et al.) which is also the reference temperature in this study. In each of the 10 cases requiring extra pressure, the temperature exceeded the reference temperature. More significantly, a surge of heat was observed in each of these cases This observations led to addtional 20 drilling experiments on dense bones. For 10 of these cases, the pressure of 1,250g was applied. For the other 10, 1.750g were applied. In each of these cases, it was also observed that the temperature rose abruptly far above the thresh old temperature of $47^{\circ}C$, sometimes even to 70 or $80^{\circ}C$. It was also observed that the increased drilling pressure influenced the shortening of drilling time more than the rise of drilling temperature. This suggests the desirability of clinically reconsidering application of extra pressures to prevent possible injury to bone tissues. An analysis of these two extra pressure groups of 1,250g and 1,750g revealed that the t-statistics for reduced amount of drilling time due to extra pressure and increased peak temperature due to the same were 10.80 and 2.08 respectively suggesting that drilling time was more influenced than temperature. All the subsequent drillings after the drilling with a 2mm twist drill did not produce excessive heat, i.e. the heat generation is at the same or below the body temperature level. Some of screw tap, pilot, and countersink showed negative correlation coefficients between the generated heat and the drilling time. indicating the more the drilling time, the lower the temperature. The study also revealed that the drilling time was increased as a function of frequency of the use of the drill. Under the drilling pressure of 750g, it was revealed that the drilling time for an old twist drill that has already drilled 40 times was 4.5 times longer than a new drill The measurement was taken for the first 10 drillings of a new drill and 10 drillings of an old drill that has already been used for 40 drillings. 'Test Statistics' of small samples t-test was 3.49, confirming that the used twist drills require longer drilling time than new ones. On the other hand, it was revealed that there was no significant difference in drilling temperature between the new drill and the old twist drill. Finally, the following conclusions were reached from this study : 1 Used drilling bur causes almost no change in drilling temperature but increase in drilling time through 50 drillings under the manufacturer-recommended cooling conditions and the drilling pressure of 750g. 2. The heat that is generated through drilling mattered only in the case of 2mm twist drills, the first drill to be used in bone drilling process for all the other drills there is no significant problem. 3. If the drilling pressure is increased when a 2mm twist drill reaches a dense bone, the temperature rises abruptly even under the manufacturer-recommended cooling conditions. 4. Drilling heat was the highest at the final moment of the drilling process.

Study on the production of porous CuO/MnO2 using the mix proportioning method and their properties (반응몰비에 따른 다공성 CuO/MnO2의 제조 및 특성 연구)

  • Kim, W.G.;Woo, D.S.;Cho, N.J.;Kim, Y.O.;Lee, H.S.
    • Analytical Science and Technology
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    • v.28 no.3
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    • pp.182-186
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    • 2015
  • In this study, the porous CuO/MnO2 catalyst was prepared through the co-precipitation process from an aqueous solution of potassium permanganate (KMnO4), manganese(II) acetate (Mn(CH3COO)2·4H2O) and copper(II) acetate (Cu(CH3COO)2·H2O). The phase change in MnO2 was analyzed according to the reaction molar ratio of KMnO4 to Mn(CH3COO)2. The reaction mole ratio of KMnO4 to Mn(CH3COO)2·4H2O was varied at 0.3:1, 0.6:1, and 1:1. The aqueous solution of Cu(CH3COO)2 was injected into a mixed solution of KMnO4 and Mn(CH3COO)2 to 10~75 wt% relative to MnO2. The Cu ion co-precipitates as CuO with MnO2 in a highly dispersed state on MnO2. The physicochemical property of the prepared CuO/MnO2 was analyzed by using the TGA, DSC, XRD, SEM, and BET. The different phase types of MnO2 were prepared according to the reaction mole ratio of KMnO4 to Mn(CH3COO)2·4H2O. The results confirmed that the porous CuO/MnO2 catalyst with γ-phase MnO2 was produced in the reaction mole ratio of KMnO4 to Mn(CH3COO)2 as 0.6:1 at room temperature.

Analysis of the Issues received by Quality Improvement Department and their Management in a Medical Center (일 의료원의 통합 고충처리센터 접수 내용과 이에 대한 해결방안 분석)

  • Tark, Kwan-Chul;Park, Hyun-Ju;Chun, Ja-Hae;Kang, Eun-Sook;Moon, Ju-Young;Choi, Mi-Young;Kim, Hyun-Ju;Kang, Jin-Kyung
    • Quality Improvement in Health Care
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    • v.7 no.1
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    • pp.118-131
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    • 2000
  • Background : A continuous healthcare quality improvement is needed to provide high quality healthcare service as well as to maintain trust in terms of satisfying the needs of the patients. Recently it also became an essential issue. in hospital management, recognized for it's competitive potentiality among healthcare organization groups. This study was conducted to analyze patient complaints and issues received by the Quality Improvement Department. Its purpose is to improve healthcare qualities within the hospital, as well as establish policies and appropriate strategies in hospital management. Method : From July 1st to September 30th of the year 1999, we analyzed all complaints and issues made by various patients and their families, which were received through 24 hour phone consultation, numerous suggestion boxes, letters and E-mails, The issues were classified into 16 different categories based on a Patient Satisfaction Assessment Tool. All data were segregated according to the departmental frequencies and their contents. To come up with for environmental and patient satisfaction improvement, all complaints or issues were communicated with hospital administrators, medical and nursing staff and employees. Comprehensive customer satisfaction activities including improving phone etiquette were discussed in Customer Satisfaction Team, CQI Team and each Department. All opportunities for improvement were implemented. Feedback actions were discussed. Results : A total of 317 cases were collected. Issues regarding parking and other accommodation facilities were most common complaints that were 14.5% of total. Issues regarding admission rooms (10.7%), admission procedures (10.7%), waiting room environment (8.8%), nurses and nurse assistants (7.6%), physicians (6.6%) and others (23%) followed. Thirteen of 45 departments received more than 8 complaints. The Nursing Department had the most complaint, receiving 9.8% of total complaints. Complaints regarding the Nursing Department were predominantly related to the environment of patient rooms. The Department of Psychiatry for phone etiquette (4.7%), Department of Otolaryngology for the nursing staff's attitude and phone etiquette (4.4%), and the Admission Department followed. As a part of efforts to improve patient satisfaction, a new parking structure was built and reallocation of the parking space was done. Renovation of other accommodation facilities were carried out by hospital administration, Monthly phone call and answering attitude survey was done by QI Department. Based on this survey we made a phone etiquette manual and distributed throughout the hospital. Compare to the last year, Patient Satisfaction Index measured by Korea Productivity Center using National Customer Satisfaction Index was improved 7 points. According to our organization's own study, we confirmed the phone etiquette was improved 11% than last year. Conclusions : Issues related to parking and other accommodation facilities ranked first followed by complaints made regarding the patient care area, the admission and cashier process, and nurses' and doctors' attitude. The Nursing and Psychiatry Departments need improvement regarding phone etiquette. Results were shared and played a vital role in policymaking and strategic planning of the hospital. It is imperative that we keep our database updated by listening to and solving the needs of each patient. The CQI activities can be achieved only by full commitment of the hospital top management supported by related personal.

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Physicochemical Quality Characteristics and Antioxidant Activity of Wasabi (Wasabia japonica) Leaf and Petiole Extracts (고추냉이 잎, 엽병 추출물의 이화학적 특성과 항산화 활성)

  • Sung, Eun Hee;Shin, Se Mi;Kang, Yoon-Han
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.3
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    • pp.335-342
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    • 2017
  • In this study, we investigated the physicochemical quality characteristics and antioxidant activities of water extracts ($20^{\circ}C$ and $95^{\circ}C$) against different parts (leaf and petiole) from Wasabia japonica (wasabi). Water extracts were divided into six types of wasabi powders: leaf hot air dried (LD), petiole hot air dried (PD), whole (leaf+petiole) hot air dried (WD), leaf steamed and hot air dried (LSD), petiole steamed and hot air dried (PSD), and whole steamed and hot air dried (WSD). Turbidity was higher in wasabi $20^{\circ}C$ water extracts than in $95^{\circ}C$ hot water extracts. Browning degree was higher in wasabi leaf extracts than in petiole extracts. The pH of hot water extraction was lower than that of room temperature extraction. Wasabi extracts did not show much difference in Hunter's color values according to extraction temperature, expected that b value of yellowness was significantly higher in leaf extracts than in petiole extracts. Carbazole pectin contents of leaf extracts were significantly higher than in petiole extracts, however water soluble pectin was higher in petiole extracts. The total polyphenol contents of LD20 and LD95 were 1,561.43 mg gallic acid equivalent (GAE)/100 g and 1,163.02 mg GAE/100 g, respectively, and total polyphenols decreased during hot water extraction. Extracts from different parts of wasabi showed a significant difference in total flavonoid contents. Total flavonoid contents of LD20, LD95, PD20, and PD95 were 554.44 mg/100 g, 396.65 mg/100 g, 55.42 mg/100 g, and 47.68 mg/100 g, respectively. In the sensory evaluation, LD95 extract showed significantly higher values than other samples in terms of color, flavor, taste, mouth feeling, and overall acceptability. In the analysis of sourness, saltiness, umami, sweetness, and bitterness taste by an electronic tongue, the sourness values of LD20 and PSD95, saltiness values of WSD20 and WSD95, and umami values of PD20 and PD95 were significantly higher than other extracts. The results of this study suggest that wasabi leaf and petiole extracts enhance qualities and antioxidant activities when used different parts together.

A Study on the Environmental Condition and Safety in Dental Radiographic Room (치과 방사선 촬영실의 촬영실태와 방사선 안전관리 실태에 관한 조사 연구)

  • Kang, Eun-Ju;Lee, Kyung-Hee;Ju, On-Ju
    • Journal of dental hygiene science
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    • v.5 no.2
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    • pp.83-88
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    • 2005
  • In spite of relatively low level of radiation dose used at dental clinics, long term exposure may be harmful, so radiation workers at dental clinics must be well aware of its danger. This study was radiation safety management by dental hygienists in order to take preventive measures for dental hygienists and suggest ideas to develop radiation safety training programs. For this, we contacted dental hygienists working at the local dental clinics for 4 months from December of 2003 to march of 2004 and obtained the following findings. 1. Regarding the intraoral radiographic method, the average daily photographing frequency of standard films stood at one to five pieces (47.5%), and the average weekly photographing frequency of digital radiation medicine stood at less than one piece (69.8%), and the average weekly photographing frequency of bitewing films stood at less than one piece (67.7%), and and the average weekly photographing frequency of occlusal films stood at less than one piece (95.5%), and the dentistries whose average weekly photographing frequency of pediatric films stood at one to five pieces accounted for 47.1 percent. 2. Regarding the extraoral radiographic method, the average weekly photographing frequency of panorama film stood at one to five pieces (63.7%), and less than one piece (20.9%), the average weekly photographing frequency of cephalometric film stood at less than one piece (72.3%), and one to five pieces (20.1%). 3. Concerning the radiation safety management training program, only 18.7% of total 278 surveyed attended the training progra., Attendance tendency of the training program by general characteristics showed statistically significant difference according to age (p<0.01), working experience (p<0.001), and marital status (p<0.01). 4. When asked about the protective equipments against radiation exposure, 40.6% of them said "modest", and 71.1% appeared equipped with led apron as a protective tool.

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Ecological Evolution by Competitive Exclusion / An Experimental Approach with Cellular Slime Mold , Polysphondylium pallidum (경쟁배타에 의한 생태적 진화: 세포성 점균 Polysphondylium pallidum에 대한 실험적 접근)

  • ;Robert M. Eisenberg
    • The Korean Journal of Ecology
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    • v.17 no.3
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    • pp.299-310
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    • 1994
  • Intraspecific clonal interactions have important influences on a population structure of the cellular slime mold (CSM). This study was to investigate whether or not evolutionary change in a population could be induced by clonal competition, and to elucidate how various clones in a population evolve in a homogeneous environment of laboratory culture. The characteristic clones of Polysphondylium pallidum which had different resource consumption rates (RCR) and mating types I and II were selected for study. Investigation was conducted for 4 experimental time interval $(T_0-T_4)$; one experimental time interval took almost 10-14 days from inoculation to havest of fruiting bodies. Two sets of 50 clones were cultured from 50 clones at To, and RCR variations of the population were compared between $(T_0\;and\;T_4)$ for each set of clones. Each clone of the CSM had a diverse resource consumption rate, or growth rate, in a homogeneous and limited Cerophyl agar plate despite the passage of 48-56 generations from the beginning of the experiment. Diverse clones with different growth rate could coexist in one site of the homogeneous agar plate as well as heterogeneous soil microenvironment. When there was high clonal diversity of RCR, a clone in a population had high chances to encounter other clones with resultant increased clonal competition. In one set, 26 of 37 clones of mating type I were changed to mating type Il for the 4 experimental time intervals, which indicated that the rate of competitive exclusion among clones during total experiment from $(T_0\;to\;T_4)$ was 0.703. In another set, 31 of 37 clones of mating type I were changed to mating type II , having the rate of competitive exclusion 0.838. The frequency of each of mat~ng types changed by 0.93-1.29% in each successive generation. The competitive exclusion among clones occurred by 1.26-1.75% when approximately $2.6{\times}10^8$ bacterial cells were provided as food and thereafter one generation of myxamoebae of CSM elapsed at room temperature. This finding implicated that in the vegetative state of P, pallidurn there was 1.26-1.75% probabil~ty of evolutionary change per generation changing from one clone to another clone.

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An in vitro study of a few crystal growth solutions on the bracket shear bond strength (수종의 실험 결정형성용액에 의한 브라켓 전단결합강도의 비교)

  • Jeon, Yun-Ok;Lee, Ki-Soo
    • The korean journal of orthodontics
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    • v.29 no.5 s.76
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    • pp.613-625
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    • 1999
  • The purpose of this study was to compare the bracket shear bond strengths of the crystal growth solutions with those of the $37\%$ phosphric acid etch technique. The 4 crystal growth solutions were made experimentally in the lab, that is, (1) $30\%$ polyacrylic acid solution containing 0.3 M sulfuric acid (ES 1), (2) $30\%$ polyacrylic acid solution containing 0.6M sulfuric acid (ES 2), (3) $30\%$ polyacrylic acid solution containing 0.3 M sulfuric acid and 0.6 M lithium sulfate(ES 3), and (4) $30\%$ polyacrlic acid solution containing 0.3 M sulfuric acid and $5\%$ phosphoric acid(ES4). The $37\%$ phosphoric acid solution used as a control. Bovine lower incisor tooth enamel was treated by the above solutions for 60 sec, washed out for 20 sec with slow water stream, and bonded lower anterior edgewise bracket with the light curing orthodontic composite resin adhesives. The teeth bonded brackets were stored in the distilled water at room temperature for 24 h, and followed to test the bracket shear bond strength. The acid etch technque showed 177.6 kg/$cm^2$ of mean shear bond strength which was the highest among the enamel treatment solutions. ES 1 shown 58.4 kg/$cm^2$ of mean shear bond strength and that of ES 4 showed 66.5 kg/$cm^2$. There was no significant difference between the two(p>0.05). ES2 showed 110.6kg/$cm^2$ of mean shear bond strength which was $62.3\%$ of that of acid etch technique. ES 3 showed 131.1 kg/$cm^2$ of mean shear bond strength which was the highest among experimental crystal growth solutions and which was $74\%$ of that of acid etch technique. The shear bond strengths of the crystal growth solutions were significantly lower that that of acid etch technique(p<0.05). The results sugest that although bracket shear bond strength of $30\%$ polyacrylic acid solution containing 0.3M sulfuric acid and 0.6 M lithium sulfate were showed the highest, it is low for the clinical application of this solution.

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A Study on the Elements of Interior Design in Victorian Style (빅토리안 스타일 주택 실내 디자인에 관한 연구)

  • Kim, Jung-Keun
    • Archives of design research
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    • v.18 no.4 s.62
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    • pp.25-34
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    • 2005
  • The purpose of the present study is to investigate the characteristics of the current Victorian-style interior by reviewing the basic Victorian-style house in the past. this research was analyzed various prior studies and literatures, and found the following results: First, the Victorian-style house and interior space showed various historical trends and adopted every style from Gothic to rococo, and sometimes more than one style influenced a single place. Its formality was applied depending on the function and standard of each room. Second, the interior had many decorative things with free, irregular or other patterns, influenced by Romanticism and Naturalism. The several environmental factors such as air pollution and hygienic matter were also related with its trend. the dramatic changes in the kitchen and sanitary facilities were appeared based on the technical development, and affluent design styles were also used. All these reflected the characteristics of the Victorian age. In conclusion, the characteristics of Victorian-style were influenced by many factors including: (a) the trend of Romanticism and Naturalism, (b) consideration of family convenience based on the technical development, (c) the Socio-Environmental factors like air pollution and the social norm, and (d) reflection of the individual value in accordance with frequent contacts with foreign cultures. In this respect, it is necessary to reevaluate the Victorian-style after paying due regard to such factors.

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