• Title/Summary/Keyword: study design

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The Study on the Effect of Density and Moisture Content on Shear Strength of Soils (흙의 밀도(密度)와 함수비(含水比)가 전단강도(剪斷强度)에 미치는 영향(影響))

  • Cho, Seung-Seup;Kang, Sin-Up;Kang, Yea-Mook;Kim, Seung-Wan;Kim, Soung-Rai
    • Korean Journal of Agricultural Science
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    • v.5 no.1
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    • pp.15-28
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    • 1978
  • It has been known that the shear strength of soil is an important design parameter for the foundation of structures, the retaining walls, the slope failures and so forth. In this study, the shear test was performed by using the direct shear apparatus under various degree of the moisture content and the density of the sample soils. The results of the study were summarized as follows; 1. The shear strength of soil increased with increase in the dry density of soil, and at the same level of density of the sample the shear strength of soil showed large values on a good grading of the sample. 2. The cohesion of the soil varied directly with the dry density of it, however the internal friction angle of soil was not affected by the dry density of tile sample. 3. The shear strength of sample varied inversly with the moisture content of it, and this phenomenon was apparent on a good grad ing of sample. 4. The cohesion of soil showed maximum value when the moisture content of the soil reached optimum level and the internal friction angle decreased with increase in the moisture content of it. These phenomena were very obvious on a good grading sample, SDC-1. 5. The cohesion of the soil decreased with increase in void ratio of the sample, but the internal friction angle of the sample didn't show such tendency.

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A Study on the Influence of Consumer Type on the Choice of Next-Generation Eco-Friendly Vehicle and Consumer Purchase Intention - Comparative Study on Japan and Korea - (소비자 유형이 차세대 친환경자동차선택속성과 소비자 구매의도에 미치는 영향에 관한 연구 - 한국 일본 비교연구 -)

  • Yim, Ki-Heung;Chong, Min-Young
    • Journal of Digital Convergence
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    • v.15 no.11
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    • pp.133-146
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    • 2017
  • In recent years, the development and market participation of major makers of next-generation eco-green vehicles has been accelerating. Consumer interest has also increased. Consumer characteristics, consumption type, characteristics of next-generation eco-friendly vehicles, and government policies on next eco-green vehicles. The results of this study are as follows. In Korea, there was no significant difference by gender, age, monthly average income, and consumer type. However, there was no significant difference in purchase intention by gender, age, and monthly income, Respectively. In the case of Japan, there was no significant difference by gender, age, monthly income, and consumer type. In Korea, on the other hand, images such as brand, color, and design have positive effects on eco-friendly vehicles. In the case of Japan, image and stability have a positive effect on consumers' purchasing behavior. Therefore, it is important for Japanese consumers to consider not only the image of purchasing an eco-friendly vehicles, but also the safety of the vehicles body, appear. In the case of Korea, the socio-environmental value-seeking type has a significant relationship with the purchasing intention. In the case of socio-environmental value-seeking type, the government's support policy such as carbon dioxide tax, direct support from the national or local governments, gasoline tax, Carbon tax and fuel related tax relief showed positive effects. In the case of Japan, the price-seeking type and the socio-environmental value-seeking type were found to have a significant relationship with the purchasing intention. Both the price-seeking type and the socio-environmental value-seeking type showed that the carbon dioxide tax, Direct support, gasoline tax, gasoline tax, and carbon tax, etc. have positive effects.

The Comparative Studies on the Urban and Rural Landscape for the Plant Diversity Improvement in Pond Wetland (농촌과 도시지역 비교를 통한 연못형습지의 식생다양성 증진방안 연구)

  • Son, Jin-Kwan;Kong, Min-Jae;Kang, Dong-Hyeon;Nam, Hong-Shik;Kim, Nam-Choon
    • Journal of Wetlands Research
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    • v.17 no.1
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    • pp.62-74
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    • 2015
  • Urban areas are variously under threat including deterioration of ecological functions. Many pond wetland types have been created as part of an effort to improve and restore this urban environment. This study was arranged to examine improvement plans of wetlands in urban areas by analyzing semi-natural wetlands in farm areas. As for environment for water quality, it suggested the inflow of natural water neighboring rivers or the direct inflow of rain as the improvement plans. The result which analyzed soil pH, OM, and T-N content of the soil environment mentioned that urban areas supplied artificial sluices, removed apoptotic bodies, and used artificial soil and waterproofing materials and use of natural materials in design and construction, the sluice state of the natural form, and negligence of autumn plants were suggested as the improvement plans. Florae appeared in the subject sites of the study have found that there are 35 families 69 species in urban areas and 53 families 142 species in rural areas. As the average has found that there are 18.5 families 29.3 species in 4 urban areas and 26.3 families 53.5 species in 4 rural areas, the big difference between them was analyzed. As the cause has found that there are differences in yearly plants in farming areas when compared to urban areas, creation of various basic environments including soil and water quality was suggested to make yearly plants settle down widely. Naturalized plants have found that there are no big differences between urban areas and rural areas. However, the average of the naturalized ratio in urban areas is 17.4% as the naturalized plants are about 1/4 of the appeared plants. As it was analyzed to be higher than 7.7%, the average of the naturalized ratio in farming areas as the big difference, creation of various inhabiting environments was suggested to make more yearly plants appear like the analyzed result of the life type. Consideration of placement, materials, and inhabiting environments was suggested to make creation of wetlands well appreciated to improve functions of wetlands in urban areas. It is expected that the above results of the study will be utilized in creation and improvement of the pond wetlands which can play a huge role in increase and improvement of biological diversity in urban areas.

Effect of Shift Interval for the Clinical Nurse on the Circadian Rhythm (임상 간호사의 교대근무 기간이 circadian rhythm 변화에 미치는 영향)

  • 황애란;정현숙;임영신;이혜원;김조자
    • Journal of Korean Academy of Nursing
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    • v.21 no.2
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    • pp.129-149
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    • 1991
  • Circadian rhythm is entrained in the 24-hour time interval by periodic factors in the environment, known as zeitgeber. But most rotating work schedules are outside the range of the entrainment of the pacemaker timing the human circadian sleep - wake cycle. It has been postulated that physiological and emotional disturbances occur in most human functions when the circadian rhythm is disturbed. So application of circadian principles to the design of shift schedules can aid in maintaining the temporal integrity of the circadian system and thereby minimize for the shift worker any detrimental consequences of circadian disruption. This study was a quasi-experimental study to test the effect of shift intervals for the clinical nurse on the circadian rhythm. Twenty nurses newly employed in general units of two hospitals were selected as an experimental group and twelve college nursing students as a control group. Both groups were selected according to an established criteria using a purposive sampling technique. Ten subjects were assigned to a weekly shift group and another ten to a biweekly shift group engaged in a semi -continuous shift schedule(sunday off) with a backward direction, that is, morning -evening - night shift. The control group worked a morning shift for 42 days. Oral temperature rhythm, waking tim, sleep - wake cycle, fatigue, and mental performance were measured during the experimental period. The data collection period was from April 30, 1990 to June 10, 1990. MANOVA, paired t-test, ANOVA, and Student Newman Keuls method were used for statistical analysis. The results are summarized as follows. 1. Phase delay in the acrophase of temperature rhythm was shown according to the backward rotating shift. A complete adaptation to work on the night shift was achieved between the sixth and ninth day of the night shift. 2. There was no difference in either waking time or sleep- wake cycle according to the duration of the working day for every shift group. Significant difference was found in the waking time and the sleep -wake cycle for subjects on the morning, evening, and night shift in both of the shift groups(weekly shift group : λ=0.121, p<0.01, λ=0.112, p<0.01, biweekly shift group : λ=0.116, p<0.01, λ=0.084, p<0.01). 3. There was no difference in fatigue between the first working day and the last working day for the control group and for the biweekly shift group. In the weekly shift group, physical fatigue was significantly different for the first day and the sixth day of the night shift(t=-2.28, p<0.05). Physical fatigue and total fatigue on the first day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F=5.79, p<0.01, F=4.56, p<0.05). There was a significant difference between the shift groups and the control group(p<0.05), Physical fatigue, neurosensory fatigue and total fatigue on the last day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F=12.65, p<0.01, F=7.77, p<0.01, F=9.68, p<0.01). There was a significant difference between the shift groups and the control group(p<0.05). 4. No difference in mental performance was seen between the first day and the last day of work in each case. An arithmatic test on the first day of the night shift revealed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F=3.79, p<0.05). There was a significant difference between the shift groups and the control group(p<0.05) . The digital symbol substitution test and the arithmetic test on the last day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F=3.68, p<0.05, F=5.55, p<0.01), and both showed a significant difference between the shift groups and the control group(p<0.05). Accordingly, this study showed that during night duty, the waking time, sleep- wake cycle, and fatigue increased and mental performance decreased compared with morning and evening duty. It was also found that the weekly shift group had a higher fatigue score on the sixth day of night duty as compared to the -first day, but the waking time, sleep- wake cycle, and mental performance revealed no difference for the duration of the night duty or between shift groups, and complete adaptation of temperature rhythm was achieved between the sixth and ninth day of night duty. It is possible to conclude from these results that for intermediate circadian type in a healthy young woman, a biweekly shift system is more compatible with the circadian timing system than weekly shift system.

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Development of cardiopulmonary resuscitation nursing education program of web-based instruction (웹 기반의 심폐소생술 간호교육 프로그램 개발)

  • Sin, Hae-Won;Hong, Hae-Sook
    • Journal of Korean Biological Nursing Science
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    • v.4 no.1
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    • pp.25-39
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    • 2002
  • The purpose of this study is to develop and evaluate a web-based instruction Program(WBI) to help nurses improving their knowledge and skill of cardiopulmonary resuscitation. Using the model of web-based instruction(WBI) program designed by Rhu(1999), this study was carried out during February-April 2002 in five different steps; analysis, design, data collection and reconstruction, programming and publishing, and evaluation. The results of the study were as follows; 1) The goal of this program was focused on improving accuracy of knowledge and skills of cardiopulmonary resuscitation. The program texts consists of the concepts and importances of cardiopulmonary resuscitation(CPR), basic life support(BLS), advanced cardiac life support(ACLS), treatment of CPR, nursing care after CPR treatment. And in the file making step, photographs, drawings and image files were collected and edited by web-editor(Namo), scanner and Adobe photoshop program. Then, the files were modified and posted on the web by file transfer protocol(FTP). Finally, the program was demonstrated and once again revised by the result, and then completed. 2) For the evaluation of the program, 36 nurses who in K university hospital located in D city, and related questionnaire were distributed to them as well. Higher scores were given by the nurses in its learning contents with $4.2{\pm}.67$, and in its structuring and interaction of the program with $4.0{\pm}.79$, and also in its satisfactory of the program with $4.2{\pm}.58$ respectively. In conclusion, if the contents of this WBI educational program upgrade further based upon analysis and applying of the results the program evaluation, it is considered as an effective tool to implement for continuing education as life-long educational system for nurse.

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A PHOTOELASTIC STUDY ON THE INITIAL STRESS DISTRIBUTION OF 3 TYPES TMA MULTI-VERTICAL LOOP ARCH WIRE (TMA wire로 제작된 3종류의 MVLAW(Multi-Vertical Loop Arch Wire)의 초기응력분포에 관한 광탄성학적 연구)

  • Lee, Hyeong-Chul;Chun, Youn-Sic
    • The korean journal of orthodontics
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    • v.25 no.1 s.48
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    • pp.73-85
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    • 1995
  • Multi-Vertical Loop Arch Wire(MVLAW) is a kind of appliance for uprighting the mesially inclined posterior teeth axes simultaneously. In this study MVLAW was classified as 3 types by modifing the vertical loop design and named type A, B and C. Each MVLAW was fabricated from .017'x.025' TMA wire and preactivated at the distal end of the open vertical loop with 10 degree tip-back bend(type B has an electric welding stop at the distal end of each loop and type C has no electric welding stop). Type A MVLAW was preactivated at the apex of each open vertical loop with 10 degree tip-back bend(the electric welding stop of type A is positionod at the mesial side of each loop). The aim of the present study was to identify when and which MVLAW is more effective to correct the buccal segment axes simultaneously. The Photoelastic overview of the upper and lower right quadrant showed that stress concentrations were observed in its photoelastic model. The obtained results were as follows : 1. Higher level compression can be seen clearly at the distal curvature of the lower 1st and 2nd molar when A type MVLAW was applied without short class m elastic, but mild compression cannot be seen at the distal curvature of lower anterior teeth using the class m elastic. 2. Higher concentration was presented at the mesial curvature from the lower 1st premolar to the 2nd molar than the anterior teeth when B type MVLAW without short class III elastic was applied, but using the short class III elastic, higher concentration of compression was presented in the anterior teeth area. 3. Areas of higher compression and tension were not observed at the mesial and distal curvature of the entire 1ower teeth except lower central and lateral incisors in C type MVLAW without short class III elastic, but using the short class III elastic, higher concentration was seen at the mesial curvature of the lower 1st premolar and 1ower anterior teeth.

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Suggestion on the Optimal Length of Long Tunnels Considering Traffic Safety Characteristics (교통안전 특성을 고려한 장대터널 적정길이 제시)

  • Kim, Joong-Hyo;Lee, Jeong-Hwan;Kwon, Sung Dae;Ha, Dong Ik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.1
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    • pp.203-211
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    • 2014
  • Tunnel reduces travel time as and it is essential facilities for the eco-friendly road construction. In recent years, It has been accelerating the tunnel construction to provide a higher level of traffic service but a driver driving in the narrow and dark tunnel takes characteristically psychological anxiety and the restriction of the sight. Moreover, A driver passing through more than 1,000m long tunnel, as to pass inside the monotonous form of the tunnel for a long time can cause drowsiness and increase the driver load. This driver load can degrade road-holding of the inside of the long tunnel highly and pose a high risk of accidents. Accordingly, In this study is to present the proper length of the Tunnel, considering the characteristics of traffic accident. For this, this study is that the long tunnel that affects traffic safety traffic safety variables are selected and classified. Traffic safety variables are classified in detail as a variable of the traffic accident and velocity one, the applicable variables the number of the traffic accident, the ratio of the traffic accident, driving velocity, the individual vehicle velocity etc. Traffic safety variables are categorized as more than a pole length of the tunnel in order to examine its impact on correlation analysis. The results indicate significant results in traffic accidents in accordance with traffic accidents, traffic safety, selects the variable was Variable depending on the length of the tunnel traffic safety point of significantly increasing the possibility of an accident can be seen as a high point. And the point of the Distribution of selected variables in order to create a traffic safety was a significant increase in traffic safety variables was set at critical intervals. Before reaching the critical point and the corresponding length of the long tunnel was set at the proper length. In this study, the optimum length of the proposed long tunnel through the long tunnel that occur in the future to contribute to reducing traffic accidents would be able to be determined.

A Proposal for a Global Market Entry Strategy into the Korean Apparel Industry based on the Italian Fashion Industry - Use of Foreign Exhibitions and Showrooms - (이태리 패션산업을 근거로 본 한국 의류산업 해외진출을 위한 제언 - 박람회 및 쇼룸 활용 -)

  • Kim, Yong-Ju;Lee, Jin-Hee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.32 no.12
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    • pp.1903-1914
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    • 2008
  • The purpose of this study was to propose an efficient and feasible global market entry strategy for the Korean apparel industry by analyzing the Italian fashion industry. In particular, the study investigated the role of foreign exhibitions and showrooms supported and organized by Italian fashion organizations. The methodology for this study was to analyze industrial reports, review previous studies and conduct in-depth interviews with 23 industry experts in Italy, Korea and LA. The results indicated that the most prominent factor in the Italian fashion industry was the fashion cluster, which is a strong and organic network of diverse fashion related areas No matter the size of the enterprise, firms can get practical, prompt and efficient support from diverse associations. The network operated by the associations provides strong support to each firm by organizing collections and exhibitions, and providing promotional activities. Showrooms and agents are another supportive "gate keeper", directly related to an enterprise's sales. However, Korean fashion firms did not have enough information or knowledge for foreign exhibitions, nor did they make aggressive promotional efforts in the global market. Despite the many fashion-related associations exist in Korea, their programs are too focused on visible accomplishments and are too oriented on "big company" and "big voice", rather than many "small firms". In conclusion, the Korean fashion industry-particularly the fashion industry in Seoul-has strong potential to become the center of the global fashion market in the future. However, the fashion support system that can act as the channel to promote firms and to meet global buyers needs to be supplemented. To feasibly create this system, government or industry associations should develop a strong and generous support system and network, and they must recognize the need for small firms to exist.

Expression of Serotonin(5-HT) Receptor Isotypes in Reproductive Organs of Male Rat (수컷 흰쥐 생식기관에서의 세로토닌 수용체 아형 유전자 발현)

  • 이성호
    • Development and Reproduction
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    • v.6 no.2
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    • pp.111-115
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    • 2002
  • 5-Hydroxytryptamine(5-HT; serotonin) system has been implicated in the modulation of male sexual behaviors and the secretion of reproductive hormones. In human males, selective serotonin re-uptake inhibitors(SSRIs) are known to improve the major male sexual dysfunction, premature ejaculation, through the central nervous system-mediated pathways. As numerous hormone and local factors, 5-HT may have peripheral role in the regulation of male sexual function. The expression of 5-HT receptor subtypes in the target tissue, however, has not been explored yet. The present study was undertaken to test whether the 5-HT receptor subtypes are expressed in the reproductive tissues of male rat, especially in ejaculatory machinery such as seminal vesicle and vas deferens. To do this, reverse transcription-polymerase chain reaction(RT-PCR) and Southern blot analysis were employed. The transcripts for the 1A, 1B and 2C subtypes of 5-HT receptor were amplified in all the tested tissues. The present study demonstrated the expression of 5-HT receptor in the rat ejaculatory machinery, suggesting that 5-HT may play a pivotal role in the male sexual function via not only central pathway but also peripheral route. Further study on the receptor subtype-specific effect and their harmonized mode of action will be needed to establish the understanding of ejaculation mechanism and drug design.

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Comparison of Color Quality, Winter Color, and Spring Green-up among Major Turfgrasses Grown under Three Different Soil Systems (세 종류 잔디지반 구조에서 주요 초종의 엽색품질, 동절기 색상 및 이른 봄 녹화 특성비교)

  • Kim, Kyoung-Nam
    • Horticultural Science & Technology
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    • v.31 no.3
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    • pp.259-268
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    • 2013
  • This study was carried out to evaluate the visual turfgrass's color quality, winter color, and spring green-up under three different soil systems and to make a practical use for sports turf design and construction. Several turfgrasses were evaluated in multi-layer, USGA and mono-layer systems. Turfgrass entries in the study comprised of 3 cultivars from Korean lawngrass (Zoysia japonica Steud.) of typical warm-season grass (WSG) and 3 blends and 3 mixtures from Kentucky bluegrass (KB, Poa pratensis L.), perennial ryegrass (PR, Lolium perenne L.), and tall fescue (TF, Festuca arundinacea Schreb.) of cool-season grass (CSG). Significant differences were observed in the turfgrass's color quality, winter color, and spring green-up in the study. Seasonal variation of visual turf color greatly occurred according to soil systems and turfgrasses. Multi-layer and USGA systems were highly associated with better visual color ratings, as compared with mono-layer system. Regardless of soil system, visual turf color in all entries was better from spring to fall than in winter. Great color differences were observed during a period of early December to early spring. CSG produced a better color quality over WSG in any soil system. Overall color ratings for CSG were KB > PR > Mixtures > TF. As for a winter color, its ranking was USGA > multi-layer > mono-layer system. No difference was found in winter among cultivars of Korean lawngrass, being completely brown, but great differences among CSG. Rated best for winter color was PR, followed by CSG mixtures, KB and finally TF in order. It was generally conceded that fast green-up in spring was greatly related with multi-layer over mono-layer system and also CSG over WSG. Among CSG, TF had a fastest green-up. PR was also fast in green-up, but poor in color uniformity. KB, however, was the slowest due to shallow rooting system, when compared with other CSGs. These results demonstrate color differences were greatly variable according to soil systems and also among turfgrass species. A precise decision should be made in selecting turfgrass species and soil system. Multi-layer and USGA systems were considered as the suitable one for turfgrass color quality, winter color and spring green-up. It is a great necessity to combine proper soil system, right turfgrass species, and appropriate mixing rates by a concept-oriented approach, when establishing garden, parks, soccer field, and golf courses and so on.