• 한국생활과학회지
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• 제18권2호
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• pp.407-418
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• 2009

In our modern society along with high speed economic growth and improvement of living conditions and through concentration of people in cities cars became essential necessities for people living in modern society. Due to social and economic conditions and for the need of recycling of materials and as a countermeasure for waste of materials importance of car service is stressed. In this connection need for improvement of working clothes which are suitable for safety and working efficiency in a difficult working environment is essential. However most of working clothes now being sold in the market are produced without consideration of ergonomic aspects of wearers of working clothes. For this reason there is need for basic research on development of working clothes which improve safety and comfort for working of car service workers. Accordingly in this study this author carried out research on fitness, level of satisfaction and dissatisfaction, suitability for movement and level of demand for improvement in working clothes with focus on workers at car service firms and direction for its improvement was explored. This study is intended to provide basic data for development of functional pattern of working clothes for car service workers in future.

• 한국농공학회지
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• 제37권1호
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• pp.49-54
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• 1995

Three types of floating-type automatic inlet were developed for the purpose of reduc- ing farmer's working hours required for water management and saving irrigation water. The point of automation is to use a float within the inlet which is floated and sinked by the ponding depth of paddy field, Thus opens and closes the control gate of irrigation. Suitability of each inlet may depend on production cost, applicability to paddy field condi- tions, and feasibility to farmers, etc. The first model was composed of three parts : chamber for irrigation control gate, chamber for float controlled by ponding depth, and connection bar between the two parts. It was designed to open and close the control gate gradually as the ponding depth drops and rises to a certain level. The second model was designed to improve the weak point of the first model which is the imperfect-closing of gate when it approaches to the end of ir- rigation. A switch-spring was equipped above the connection bar for perfect opening and closing of gate when the ponding depth reaches to a certain level. The third model was designed by combining the two chambers, that is, cut in halves the inlet volume of the above two models. Magnets were equipped above the float for perfect opening and closing gate. The functional experiment for three developed inlets was successfully carried out and the rating curves were derived.

• 대한금속재료학회지
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• 제50권3호
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• pp.191-200
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• 2012

The purpose of this paper is to review the state of laser processing technology using metal powders. In recent years, a series of research and development efforts have been undertaken worldwide to develop laser processing technologies to fabricate metal-based parts. Layered manufacturing by the laser melting process is gaining ground for use in manufacturing rapid prototypes (RP), tools (RT) and functional end products. Selective laser sintering / melting (SLS/SLM) is one of the most rapidly growing rapid prototyping techniques. This is mainly due to the processes's suitability for almost any materials, including polymers, metals, ceramics and many types of composites. The interaction between the laser beam and the powder material used in the laser melting process is one of the dominant phenomena defining feasibility and quality. In the case of SLS, the powder is not fully melted during laser scanning, therefore the SLS-processed parts are not fully dense and have relatively low strength. To overcome this disadvantage, SLM and laser cladding (LC) processes have been used to enable full melting of the powder. Further studies on the laser processing technology will be continued due to the many potential applications that the technology offers.

• Structural Engineering and Mechanics
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• 제19권3호
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• pp.321-336
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• 2005

The structural feasibility of a variety of non-conventional sludge digesters, in the form of thin shells of revolution constructed in concrete, has formed the subject of investigation of a recent programme of research at the University of Cape Town. Such forms are usually known in the literature as "egg-shaped", and the advantages of these over conventional digesters of the wide-cylindrical type are now well-recognised: superior mixing efficiency, less accumulation of deposits at the bottom, easier removal of bottom deposits and surface crust, reduced heat losses, and so forth. With the aim of exploring the structural feasibility of various non-conventional forms for concrete sludge digesters, and making available usable analytical data and practical guidelines for the design of such thin shell structures, a number of theoretical studies have recently been undertaken, and these have covered conical assemblies, spherical assemblies and parabolic ogival configurations. The purpose of the present paper is to bring together the different analytical approaches employed in each of these studies, summarise the main findings in each case, draw comparisons among the various studied configurations with regard to structural efficiency and functional suitability, and make appropriate conclusions and recommendations.

• 한국식생활문화학회지
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• 제36권4호
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• pp.382-391
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• 2021

This study was conducted to find out the bakery processing suitability of maca and to develop rice-based processed foods. We investigated the antioxidant activity and physicochemical properties of rice cookies prepared with the addition of maca (Lepidium meyenii) powder (1%, 2%, 3%, and 4% of the total materials). We observed an increase in the total polyphenol and flavonoid content, and DPPH-ABTS⁺ radical scavenging activity of the rice cookies as the proportion of added maca powder increased (p<0.05). The quality characteristics such as the "a" value, "b" value, and the hardness of the cookies increased with an increase in the proportion of maca powder (p<0.05) in the cookie, whereas the moisture content, pH of the dough, spread ratio, loss rate, leavening rate, and "L" values showed a significant decrease (p<0.05). In the sensory evaluation results, consumer acceptability showed a significantly higher value in the 2% maca cookie group (p<0.05), and the characteristic intensity rating (color, flavor, bitterness) increased as the proportion of maca added to the cookie increased (p<0.05). Therefore, this suggests that adding 2% maca powder as the functional ingredient in rice cookies can result in rice bakery products with excellent qualities.

• 생태와환경
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• 제57권2호
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• pp.111-122
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• 2024

Zooplankton biomass is essential for understanding the quantitative structure of lake food webs and for the functional assessment of biotic interactions. In this study, we aimed to propose a biomass (dry weight) estimation method using the body length of cyclopoid copepods. These copepods play an important role as omnivores in lake zooplankton communities and contribute significantly to biomass. We validated several previously proposed estimation equations against direct measurements and compared the suitability of prosomal length versus total length of copepods to suggest a more appropriate estimation equation. After comparing the regression analysis results of various candidate equations with the actual values measured on a microbalance-using the coefficient of variation, mean absolute error, and coefficient of determination-it was determined that the Total Length-DW exponential regression equation [W=0.7775×e^2.0183L; W (㎍), L (mm)] could be used to calculate biomass with higher accuracy. However, considering practical issues such as the morphological similarity between species and genera of copepods and the limitations of classifying copepodid stages, we derived a general regression equation for the pooled copepod community rather than a species-specific regression equation.

• 한국의학물리학회지:의학물리
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• 제22권1호
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• pp.18-27
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• 2011

본 연구에서는 3.0 Tesla 기능적 자기공명영상법(function magnetic resonance imaging, fMRI)을 이용하여 자연과 도시풍경의 시각 자극에 따른 대뇌중추의 활성화 영역의 차이점을 규명하고, 아울러 대뇌 부위별 활성화 양상의 차이점을 정량적으로 분석하여 자연과 도시의 생활환경을 인체친화성과 관련하여 신경해부학적 측면에서 연구하고자 하였다. 오른손잡이 정상인 27명(평균 $27.3{\pm}3.7$세)을 대상으로 3.0T MRI를 사용하여 기능적 자기공명영상을 얻었다. 대뇌의 활성화를 유도하기 위한 시각 자극 패러다임은 3번의 휴지기와 2번의 활성기로 구성되어 있고, 각각의 휴지기와 활성기 지속시간은 30초와 120초로 하였다. 전체 피험자 27예의 설문결과를 바탕으로 자연풍경을 선호한 26예와 도시풍경을 비선호한 14예를 두 그룹으로 나눈 후 활성화 양상을 비교하였다. 자연과 도시풍경 간의 대뇌 활성화 양상을 비교한 결과, 도시풍경에 비하여 자연풍경을 보았을 때 유의한 수준(p<0.05)에서 활성화를 보인 영역은 뇌섬엽, 중전두회, 설전부, 미상핵, 상두정회, 상후두회, 방추상회, 창백핵이었으며, 도시풍경에서는 하전두회, 해마방회, 중심후회, 상측두회, 편도체, 후대상회 영역에서 우세한 활성화가 관찰되었다. 자연풍경에서는 도시풍경에 비해 주로 긍정적 정서와 관련된 영역에서 활성화가 나타난 반면, 도시풍경에서는 두려움, 공포, 불쾌감을 느낄 때 반응하는 편도체와 같은 부정적 정서와 관련된 영역에서 활성화가 나타났다. 본 연구에서는 3.0T 기능적 자기공명영상법 이용하여 자연과 도시풍경의 시각 자극에 따른 대뇌중추의 활성화 양상의 차이점을 신경해부학적인 측면에서 정성 정량적으로 평가할 수 있었고, 이러한 결과는 인간이 본능적으로 느낄 수 있는 희로애락의 감정에 따른 대뇌 활성화와 관련하여 생태환경의 인체 친화성과 쾌적성에 대한 객관적인 평가 지표로서 응용될 수 있을 것으로 생각된다.

• 한국지역지리학회지
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• 제13권2호
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• pp.129-142
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• 2007

본 연구의 목적은 휴경 연차에 따른 논토양의 물리 화학적 특성과 식생의 변화를 분석함으로써 묵논의 습지 생태계로서의 가치와 다양한 생물 서식처로서의 기능에 적합한지를 평가하는 것이다. 본 연구의 물리 화학적 특성과 식생 천이과정, 그리고 묵논 습지로서의 기능적 가치 분석 결과를 요약하면 다음과 같다. 첫째, 휴경 연수가 증가 할수록 표토가 조립화 되는 경향으로 나타났다. 둘째, 휴경 연수에 따라 유기물과 유효인산, 칼슘의 함량이 차이가 나타났으며, 칼륨과 마그네슘, CEC는 크게 변하지 않는 것으로 분석되었다. 셋째, 식생 천이과정의 단계별로 식물종 구성비를 보면, 출현종수는 초기에 14종에서 중기로 갈수록 증가하고 후기로 가면 다시 줄어드는 것으로 나타났다. 식물 조사 지소별 종구성적 조합에 의한 유사도 분석 결과를 보면 크게 천이단계별로 3그룹으로 분류되어 나타났다. 천이 초기는 댓골 상단, 하단이 중기 단계는 논방골 1단, 2단, 3단이, 천이 후기는 논방골 4단, 5단으로 그룹화 되었다. 넷째, 환경부 습지기능평가표와 RAM을 기준으로 논방골 묵논 습지에 대한 기능가치분석을 실시 한 결과 전체 가치평균이 2.13으로 "보통"에 해당하는 것으로 나타났다.

• Journal of Ecology and Environment
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• 제45권4호
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• pp.277-286
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• 2021

Background: As trade increases, the influx of various alien species and their spread to new regions are prevalent and no longer a special problem. Anthropogenic activities and climate changes have made the distribution of alien species out of their native range common. As a result, alien species can be easily found anywhere, and they have nothing but only a few differences in intensity. The prevalent distribution of alien species adversely affects the ecosystem, and a strategic management plan must be established to control them effectively. To this end, hot spots and cold spots were analyzed according to the degree of distribution of invasive alien plants, and major environmental factors related to hot spots were found. We analyzed the 10,287 distribution points of 126 species of alien plants collected through the national survey of alien species by the hierarchical model of species communities (HMSC) framework. Results: The explanatory and fourfold cross-validation predictive power of the model were 0.91 and 0.75 as AUC values, respectively. The hot spots of invasive plants were found in the Seoul metropolitan area, Daegu metropolitan city, Chungcheongbuk-do Province, southwest shore, and Jeju island. Generally, the hot spots were found where the higher maximum temperature of summer, precipitation of winter, and road density are observed, but temperature seasonality, annual temperature range, precipitation of the summer, and distance to river and sea were negatively related to the hot spots. According to the model, the functional traits accounted for 55% of the variance explained by the environmental factors. The species with higher specific leaf areas were more found where temperature seasonality was low. Taller species preferred the bigger annual temperature range. The heavier seed mass was only preferred when the max temperature of summer exceeded 29 ℃. Conclusions: In this study, hot spots were places where 2.1 times more alien plants were distributed on average than non-hot spots (33.5 vs 15.7 species). The hot spots of invasive plants were expected to appear in less stressful climate conditions, such as low fluctuation of temperature and precipitation. Also, the disturbance by anthropogenic factors or water flow had positive influences on the hot spots. These results were consistent with the previous reports about the ruderal or competitive strategies of invasive plants instead of the stress-tolerant strategy. The functional traits are closely related to the ecological strategies of plants by shaping the response of species to various environmental filters, and our result confirmed this. Therefore, in order to effectively control alien plants, it is judged that the occurrence of disturbed sites in which alien plants can grow in large quantities is minimized, and the river management of waterfronts is required.

• 토지주택연구
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• 제10권4호
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• pp.41-50
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• 2019

This study was started to study the buffer zone of Daejeon metropolitan city in order to study the policy and environment for the suitability evaluation of the use of green buffer zone. The target of the study was selected as the buffer zone of western buffer, which is frequently used in the Daejeon Metropolitan City, and a preliminary index was selected to evaluate the suitability of the green buffer zone. AHP analysis was conducted to increase the reliability of the preliminary indicators and the weight was analyzed by questionnaires to experts and practitioners. In addition, based on the existing statistical data, we rebuilt the green buffer zone and investigated the current condition, and compared and analyzed the green buffer zone and the places where they did not. The results are as follow. First, unlike the statute interpretation that construction can not be done in buffered green spaces, green buffer zones have been utilized in various ways. However, the lack of advanced citizen consciousness of the residents, the responsibility of the responsible person, and the problem of the management office alone are causing problems. Second, according to the results of AHP questionnaire analysis, functional and stability among the appropriateness indexes of green buffer zone utilization were evaluated highly. Park accessibility and utilization potential also weighed somewhat, and it was judged that the epochal trend was more important in the use of green buffer zones. Third, analysis of the status of Western green buffer zones in Daejeon showed that the utilization rate was more than half. This suggests the necessity of judging the appropriateness of the application of the green buffer zone effectively due to the change of the perception of the green buffer zone of the residents. Fourth, as a result of comparing and analyzing the site where the site is used and the site where it is not, it is found that it is used within a range that does not greatly affect each index. However, as the stability has decreased, we have decided that the utilization method is most damaging to the green zone, and we should strive to improve the stability in future. Finally, the analysis of a red clay road and a red clay road sites decreased from Class I of stability to Grade II. However, the fall figure showed a difference between the 13 % drop rate of the target location and the 5% decline rate of utilization. The difference was analyzed as the difference of width of a red clay road. This can be regarded as one of the ways of damaging the green zone to the minimum extent, which is a great advantage in selecting the future utilization plan.