• 한국분무공학회지
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• 제14권3호
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• pp.109-116
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• 2009

The purpose of this study is the experimental and numerical investigation on the DME spray characteristics in the combustion chamber according to the injection timing in a common-rail injection system. The visualization system consisted of the high speed camera with metal halide lamp was used for analyzing the spray characteristics such as spray development processes and the spray tip penetration in the free and in-cylinder spray under various ambient pressure. In order to observe the spray characteristics as a function of injection timing, the piston head shape of re-entrant type was created and the fuel injected into the chamber according to various distance between nozzle tip and piston wall in consideration of injection timing. Also, the spray and evaporation characteristics in the cylinder was calculated by using KlVA-3V code for simulating spray development process and spray tip penetration under real engine conditions. It was revealed that the high ambient pressure of 3 MPa was led to delay the spray development and evaporation of DME spray. In addition, injected sprays after BTDC 20 degrees entered the bowl region and the spray at the BTDC 30 degrees was divided into two regions. In the calculated results, the liquefied spray tip penetration and fuel evaporation were shorter and more increased as the injection timing was retarded, respectively.

• International Journal of Advanced Culture Technology
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• 제11권1호
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• pp.232-240
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• 2023

The ecological expression of art in modern society takes the harmonious developmental relationship between man and nature as an element and combines it with the various manifestations of painting as an expression of ecological artistic development. The necessary relationship for the harmonious development of nature is accurately articulated, and the ecological changes in people are expressed in integrated materials that inspire human reflection. In the pursuit of material pleasures, mankind is neglectful and indifferent to the environment. The development of composite painting in art and ecology is a process that more reveres the harmony between man and nature as well as satisfying the creative value of the work. After systematic evaluation and research, people have engaged in various structural forms of composite art painting development in the long history of art development, focusing on the integration of environmental and ecological culture. In the process of nature education going through development, the comprehensive practical development of nature education is enhanced and efforts are made to feel new ecological art ideas and new ways of valuing environmental protection. In this paper, an observational study of eco-art will be carried out, starting from the theory of hierarchical division and analyzing the contradictory relationship between man and nature. Recognize nature, understand it and feel it through eco-art painting. The analysis of the contradictory relationship between man and nature is combined with the identification of various types of information that give value to the environmental protection public, and the combination of ecological painting and nature art to achieve an upgrade of the environmental protection idea of the value of painting. In the development of artistic ecological comprehensive painting, it is necessary to put forward technical requirements and standards that meet the development of modern industry according to the characteristics and methods of ecological painting. The author of this paper discusses the necessity and social value of artistic ecological painting creation from the artist's point of view, expounds the practical achievements of ecological painting from the perspective of the history and present situation of the development of ecological aesthetics at home and abroad, and gives the concept and creative method of contemporary art comprehensive material painting in combination with his own actual situation.

• Journal of Animal Science and Technology
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• 제61권5호
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• pp.272-277
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• 2019

This study was conducted to evaluate the effects of dietary mixture of protease and probiotics on growth performance, blood constituents, and carcass characteristics of growing-finishing pigs. A total of 48 growing pigs were randomly allotted into 2 dietary (6 pigs/pen; 4 replicates/treatment). The treatments were a diet based on corn and soybean meal (CON) and CON supplemented with 0.01% of dietary mixture of protease and probiotics (MULTI). No differences were found on growth performance (average daily gain, ADG; overall, 874.06 vs. 881.14 g/d; p > 0.05), blood constituents (white blood cell, WBC; phase I, 17.51 vs. $19.96{\times}10^3/{\mu}L$; phase II, 19.65 vs. $21.95{\times}10^3/{\mu}L$; p > 0.05), and carcass characteristics during overall experimental period between CON and MULTI. In conclusion, the addition of dietary mixture of protease and probiotics in growing-finishing pig diet did not have any beneficial effects.

• 한국수정란이식학회지
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• 제31권3호
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• pp.287-291
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• 2016

For evaluating the boar semen quality, sperm motility (MOT) is an important parameter because the movement of spermatozoa indicates active metabolism, membrane integrity and fertilizing capacity. Estrogen receptors 2(ESR2) is involved in estrogen related apoptosis in cell cycle spermatogenesis, but their functions have not been confirmed in pig until now. Therefore, this study was conducted to analyze their association with sperm motility and kinematic characteristics. DNA samples from 105 Duroc pigs with records of semen motility and kinematic characteristics [Total motile spermatozoa (MOT), Curvilinear velocity(VCL), Straight-line velocity(VSL), the ratio between VSL and VCL(LIN), Amplitude of Lateral Head displacement(ALH)] were analyzed. A SNP in coding region of ESR2 g.35547A > G in exon 5 was associated with MOT (p < 0.05) in Duroc population. Therefore, we suggest that the porcine ESR2 gene may be used as a molecular marker for Duroc boar semen quality, although its functional effects were not defined yet. These results might shed new light on the roles of ESR2 in spermatogenesis as candidate gene for boar fertility, but still the lack of association across populations should be considered.

• Journal of Animal Science and Technology
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• 제61권4호
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• pp.234-238
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• 2019

This experiment was conducted to evaluate the effects of dietary protease on growth performance, blood constituents, and carcass characteristics of growing-finishing pigs. A total of 48 growing pigs (initial body weight, $34.8{\pm}0.62kg$) were randomly assigned to 2 dietary treatments (6 pigs/pen; 4 replicates/treatment). The treatments were a diet based on corn and soybean meal (CON) and CON supplemented with 0.01 % of protease (PRO). Pigs were fed respective dietary treatments with a 2-phase feeding program for 12 weeks. Pigs fed PRO had higher average daily gain (ADG; phase I, 866.38 vs. 821.75 g/d; overall, 910.96 vs. 866.30 g/d; p < 0.05) and gain to feed ratio (G:F; phase I, 0.345 vs. 0.363 g/g; p < 0.05) than those fed CON. However, there were no differences on blood constituents and carcass characteristics between CON and PRO of growing-finishing pigs. In conclusion, dietary protease supplementation in the typical diet for growing-finishing pigs improved growth rate.

• 한국지역사회생활과학회지
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• 제27권4호
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• pp.755-777
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• 2016

This study was conducted to investigate food needs for dining out in the context of rural healing tourism by surveying food preference characteristics. A total of 600 adults in an urban area completed an online questionnaire on food characteristics for rural healing tourism. Regarding the purpose of rural healing tourism, 61.2% of respondents answered 'relaxation' while 6.3% answered 'promotion of health'. Exactly 66.3% of respondents selected Korean foods (rice) as the preferable food type for dining out in the context of rural healing tourism. Respondents considered 'regionality' and 'ingredient' as more important among food quality characteristics, whereas 'professionality' was less important. Females perceived 'nutrition' and 'cooking' as more important than males. Among food characteristics of professionality, regionality, and traditionality, respondents most preferred 'using regional specialty food'. Preference for 'using traditional food' significantly increased with subject's age. Respondents rated 'balanced nutrition' most highly among food characteristics of health and nutrition. 'Seasonal food' was the most preferred food characteristic among cooking and ingredients. Females showed higher interest in nutrition, cooking, and ingredients and higher preferences related to food characteristics of nutrition, cooking, and ingredients than males. In conclusion, Korean foods (rice) or Korean full course menu items using local specialty foods or seasonal foods with balanced nutrition are needed for dining out in the context of rural healing tourism.

• 한국농공학회지
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• 제38권6호
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• pp.51-63
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• 1996

This study is about the problems found in the process of the current governments planning rural settlement area development. As a measure to solve them, It proposed the analysis method of village characteristic in terms of standard score and tried to use this method as a basic material in planning more effective rural settlement area development. On the basis of the above analysis, which is an objective basic material to solve the problems revealed in the process of the bottom-up development planning by the residents' demands, It shows the following conclusion about what method should be applied to each part according to a village's characteristics and its development level. 1. Accessibility can be a basic material for setting the local area, analyzing its settlement system, and them such development facilities as village-linking roads, rural road, or various kinds of bridges and determining the investment priority. 2. With the index of the industrial basis, we can see what village has plenty of social, economical resources including advanced industrial facilities and looking into the advance level of the industrial basis, we can get some information about determining the local area development direction such as estashing the plan to build a farm product gathering center, a collective work place, storage facilities, and special housing development. 3. Since the issue about living environment is raising it's head, compared to weakened agricultural competitive power, with the analysis of this living environment, we can get an objective basic material for solving problems caused by the local egoism and the effective investment strategy of the limited resources. Therefore, It is necessary that we should abstain from expert-centered planning and formal public opinion-collecting and on the basis of this analytic result, we should plan development. We need to continue our research about index selecting and differentiation, weight etc. and using these analysis methods, we should make up a systematic development plan by analyzing village characteristics and setting the development direction.

• 기술혁신연구
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• 제9권2호
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• pp.98-119
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• 2001

The purpose of this study is to classify the world countries into several cluste on the basis of the characteristics of the scientific and technological development, and analyse the main factors of development in each cluster. Major contributions of this study can be summarized as follows: (1) In the process of producing the composite indicators, individual indicators were adopted only if they met the condition which were logically compliable for the given time periods. Hence this thesis supports the reliability in comparing results of analysis in each period of years. (2) Could clearly capture the development characteristics and its changing process in each country.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 추계학술발표회
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• pp.316-317
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• 2005

• 한국동물학회지
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• 제36권1호
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• pp.67-76
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• 1993

The lanral characters of Petrolisthes japonicus (De Haan, 1849), Porcellanidae, were described and illustrated. The lanral development of P. juponicus includes the two zoeal and one megalopal stases. The first and second zoeal stases lasted about 4 and 10 days, respectively. It took about 14 days to attain megalopa from hatching-The larval characteristics of P. japonicus were compared with those of other knouts species of Petrolisthes. Consequently, the lanrae of P. japonicus are more closely related to P elongatus and P ornutus than other Petrolisthes species, but the present species can be distinguished from these Petrolisthes species by morphological characteristics.