• Title/Summary/Keyword: Nature Environment

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Floristic Composition, Structure, and Dynamics of Koelreuteria paniculata Communities in Daegu City (대구시 자생 모감주나무군락의 종조성, 구조 및 동태)

  • Kim, Jun-Soo;Cho, Joon-Hee;Kim, Hak-Yun;Cho, Hyun-Je
    • Journal of Korean Society of Forest Science
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    • v.108 no.2
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    • pp.168-176
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    • 2019
  • To understand the floristic composition, vegetation structure, and population dynamics of Koelreuteria paniculata communities, which are native to Daegu, South Korea, a field survey was conducted in July 2018 using phytosociological and complete enumeration methods. Based on information on vegetation and trees of >5 cm diameter at breast height collected during the field survey, we classified the community types by species composition and analyzed their vegetation strata, relative importance value (MIV), life forms, species diversity, and population structure. The community was divided into the following three types: Ulmus parvifolia-Vitex negundo var. incisa subcommunity, Securinega suffruticosa subcommunity, and Clematis apiifolia community. The vegetation unit system was organized into one community group, two communities, and two subcommunities. Vegetation coverage of the tree layer was >85%, while the herbaceous layer was <10%. MIV of K. paniculata appeared to be extremely high within all vegetation strata, with 94.3 of the tree layer, 81.6 of the subtree layer, 75.5 of the shrub layer, and 60.0 of the herbaceous layer. The species diversity (H') was significantly different among the community types, and the C. apiifolia community (2.062) was approximately four times higher than the S. suffruticosa subcommunity (0.547). The overall representative life form types were "$MM-R_5-D_4{\cdot}D_2-e$,", but there were some differences in the disseminule form among the community types. The population structure of K. paniculata showed the reverse J-shaped distribution with a high density of young individuals and low density of larger individuals among all three community types, and because no plant species within the lower vegetation could replace K. paniculata, it was considered to be a sustainable population.

FRICTION UNITS FOR THE MOON

  • Drozdov, Yu.N.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.10b
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    • pp.389-396
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    • 2002
  • In XXI century it is necessary to expect the recommencement and development of activities on mastering the Moon. In the long term it is construction of manned lunar bases with industrial, astrophysical, procuring, repair equipment and services. Interplanetary flights from the Moon demand smaller power expenditures, than from the Earth, therefore it is favourable to use its surface for the construction of space-vehicle launching sites. Flights of devices in libration points in the system 'Earth - Moon' are considered. Experience of engineering system creation for the Moon displays the great complexity in provision of serviceability and reliability of friction units. Open friction units should operate under following conditions on the Moon: pressure of environment (vacuum) $p\;>10\;^{-10}$ Pa; wide range of temperature change $+150^{\circ}C\;...170^{\circ}C$; high evaporability of lubricants; influence of temperature gradients and warping of constructions; sublimation of elements of constructional materials; irradiation of different physical nature; effect of micrometeorites; reduced gravitation; influence of abrasive particles of lunar ground; requirements on minimization of size and weight characteristics of a construction (high tension); undesirability (impossibility) of application of liquid and plastic lubricants; vibration, shock, acoustic loadings during start and landings to the Earth; difficulties in repair-regenerative operations in conditions of the Moon etc. Adhesive interaction of conjugated surfaces is the principal reason of possible failures of rubbed units on the Moon. In the research of the Moon automatic interplanetary stations of 'Luna' (USSR), 'Surveyer', 'Apollo' (USA) series were used. Stations executed functions of flying, landing, artificial satellites of the Moon, moon-rovers and manned spacecrafts such as 'Apollo'. The experimental- theoretical researches carried out in the sixtieth years on tribology for conditions of the Moon appeared to be rather useful to engineering of an outer space exploration and the decision of complex problems for the friction units operating in extreme conditions on the Earth. For the creation of highly loaded friction units for the long service life on the Moon it is required not only to use accumulated experience and designed technologies, but also to carry out wide scientific research.

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A Study on Applicability to Dual-Fuel Engine of Low Caloric Gas (저발열량 가스의 혼소엔진 적용에 관한 연구)

  • Park, Cheol-Woong;Lee, Sun-Youp;Kim, Chang-Gi;Won, Sang-Yeon;Lee, Jang-Hee
    • Journal of the Korean Institute of Gas
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    • v.14 no.1
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    • pp.15-20
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    • 2010
  • The interest on the utilization of landfill gases and biogases for energy production has been increasing due to environment concerns and global warming caused by burning fossil fuels, renewable nature of these gases. Using those synthesis gases to generate energy with engine encourages more efficient collection reducing emissions into the atmosphere and generates revenues for the operators. However the lower calorific value of synthesis gases than that of LPG or CNG affects the combustion stability and power output. Thus it becomes necessary to address disadvantages involved by studying synthesis gases in technological perspective. This paper discussed synthesis gas as a fuel for 60kW dual-fuel engine to produce power in an effective way. The methane diluted with $N_2$ was used as a fuel and developed ECU and injector driver facilitated the investigations with diesel fuel.

A Study on the Development of Design Guidelines for the Outdoor Play Settings in Child Care Center (아동보육시설의 실외놀이 환경 디자인지침 개발 연구)

  • Choi, Mock-Wha;Byun, Hea-Ryung
    • Korean Journal of Human Ecology
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    • v.16 no.4
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    • pp.855-875
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    • 2007
  • The purpose of this study is to suggest a guideline for outdoor play settings in child care centers. From March to July, 2005, data were collected from 223 directors at child care centers through a structured questionnaire, field measurement survey and non-participatory observation in seventeen child care centers in Seoul and Daejeon. The statistical methods for analysing data were frequency, percentage, mean, $X^2$ and F-test. The results showed as follows: 1)the existing outdoor playground area in child care centers should be expanded more than $4\;m^2$ per child. 2) Outdoor play facilities should be equipped with two structured play sets, a play facility for unstructured play and an adventure facility to make child's various activities possible and to promote child development. 3)flooring materials for outdoor playground should be required to use more than three kinds such as solid coverings (cf. asphalt, standard concrete), wood, lawn, soil or sands. 4)to let children enjoy various activities, outdoor playground area should be composed of various play facilities like indoor play gyms and should be independent but have good connections between play facilities depending on characteristics of play activities. 5)Play spaces of outdoor playground should be composed of physical play space, unstructured and dramatized play space, rest space, space for nature and adventure space. In addition, appropriate play equipments should be provided in respective play space.

A Study of the Dead Man's Switch considering bio-response (생체 신호를 이용한 기관사 감시시스템 연구)

  • Song, Yong-Soo;Baek, Jong-Hyen;Ko, Tae-Kyun;Kim, Yong-Kyu
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.165-171
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    • 2011
  • A Consider the dead man's switch installed in each and every locomotive cab, which support operational safety on railways around the world. The concept is very simple - every 150 to 180 seconds an illuminated push-button demands to be acknowledged so as to know that the Train Driver is alive and active. In the absence of a response over a period of minutes, the vigilance control will automatically apply the train brakes and bring the train to a stand. If we multiply the resetting of the vigilance control 60 times per hour by a 10-hour shift it equals 600 presses of the button during the shift that a Train Driver must pay attention to and acknowledge. This adds a fair bit of pressure on the train driver's job, particularly when he/she is driving through stations, with passengers moving about on platforms in an environment of complex signaling arrangements - all the while looking out for restricting signals. From this perspective, the Vigilance System's demand to be acknowledged every 150/180 seconds is disturbing and can unnecessarily take a driver's attention away from what is happening outside the confines of the cab. A much more dramatic situation can happen when a train driver is driving hour after hour at night when, by Mother's Nature request - people need to sleep. Experience and research shows that the the dead man's switch can be pressed by train driver in a state of deep relaxation and 'micro-sleep'. The vigilance control system which is applied to reduce the drive load considering bio-response multiple unit train is proposed.

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The effect of E-commerce's curation characteristics on the customer purchase intention - Focusing on the mediating effect of satisfaction - (전자상거래의 큐레이션 특성이 소비자 구매의도에 미치는 영향 - 만족도의 매개 효과를 중심으로 -)

  • Choi, Chang-Moon;Yang, Hae-Sool
    • Journal of Digital Convergence
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    • v.14 no.5
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    • pp.185-195
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    • 2016
  • The purpose of this study is to understand the nature of curation commerce in the environment of e-commerce in recent years rapidly changing and looking for ways to take advantage of it. Like the recent trend curation and subscription commerce has been in the limelight in a new way of e-commerce. However, not having appropriately adapted to the market, it has gone out of business or been changing the properties. In analyzing the specific characteristics of the migration queue commerce, it evaluated whether those characteristics do change through the mediating effect of the impact of satisfaction on purchase. This study was carried out using a structured questionnaire, by collecting the material for the 305 general public in the country and it was analyzed using stepwise regression method. After validating the hypothesis, 5 characteristics of curation commerce turned out to have a significant positive effect (+) on purchase and satisfaction of consumers using curation commerce to have a positive effect (+) on purchase. After organizing these findings and discussing the theoretical and practical implications, the direction for future research was proposed.

Metallogenesis in Korea -Explanation of the Metallogenic Map of Korea- (한국(韓國)의 광상생성도(鑛床生成圖))

  • Kim, Seon-Eok;Hwang, Duk-Hwan
    • Economic and Environmental Geology
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    • v.19 no.spc
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    • pp.73-94
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    • 1986
  • In order to make preparation of the Metallogenic Map of Korea, the writer have to collect and review the data of general geology and ore deposits of Korea which have been published up to date. The geology of Korea has been briefly simplified and grouped into the 15 formations so as to provide the base geologic map for making the Metallogenic Map of Korea. Geologic provinces of south Korea are divided into four, that is, Gyeonggi·Ryeongnam province, Ogcheon geosynclinal province, Gyeongsang basin province and Tertiary province. In the view of tectonics and related granites, the major orogenies in south Korea are as follows; Ryeongnam orogeny, Taebaeg disturbance, post-Sangweon disturbance, post-Joseon disturbance, Bulgugsa disturbance and Yeonil disturbance. Metallogenic epochs might coincide with the period of syntectonic or subsequent igneous rock intrusions accompanied with the above listed orogenies and disturbances. Thus, metallogenic epochs that are certain in Korea so far are; Precambrian periods, Paleozoic periods, Jurassic to early Cretaceous periods, late Cretaceous to early Tertiary periods, Quaternary periods and age-unknown periods. The Metallogenic Map of Korea shows 444 ore deposits and/or mines by symbols on a background adopted from the existing geologic and tectonic map. The 444 metallic and non-metallic deposits are categorized by the commodities they contain, size, geologic environment, mineralized age and mineralogic nature.

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Survey on the gross lesions of slaughtered pigs in Jeonbuk area, Korea (전북지역 도축 출하돈 병변 조사)

  • Lim, Mi-Na;Baek, Kui-Jeong;You, Ki-Hong;Cho, Hyun-Ung
    • Korean Journal of Veterinary Service
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    • v.38 no.2
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    • pp.89-94
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    • 2015
  • Respiratory disease in pigs is common in modern pork production worldwide and is often referred to as porcine respiratory disease complex (PRDC). PRDC is polymicrobial in nature, and results from infection with various combinations of primary and secondary respiratory pathogens. The control of swine respiratory disease requires an understanding of the interactions between the organisms that can cause this illness, the pig and management of the environment. This study was carried out to investigate the lesion of red internal organs in slaughtered pigs and provided assistant data for pig farms. A total of 900 lung samples, 45 farms were collected randomly from slaughtered pigs in Jeonbuk province from April to December in 2014. Gross lesions such as swine enzootic pneumonia (SEP), pleuritis, pleuropneumonia, pericarditis, liver white spots were examined for the pigs. Overall prevalence of SEP was 70.8%. According to season, the incidence occurred higher in summer than winter, fall and spring. The mean SEP score was 1.4, the highest incidence occurred in fall. The prevalence of pleuropneumonia, pleuritis, pericarditis, and milk spot was 26.1%, 71.4%, 2.8%, 21.6%, respectively. In the detection of pathogens, PRRS was not detected, PCV2 was positive in 87.6%.

Case Study on the Characteristics of Hanok Hotel (한옥호텔의 배치 및 공간특성에 관한 사례조사)

  • Kim, Sunyoung;Hwang, Yeon-Sook
    • Korean Institute of Interior Design Journal
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    • v.23 no.6
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    • pp.169-177
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    • 2014
  • The purpose of this study is to analyze the design characteristics of Hanok hotel. This study was approached by using theoretical investigation and a field survey. The field survey analyzed the current situations by conducting the master plan layout, architecture and interior design of the Hanok hotel. The field survey was tested by examining four different Hanok hotels from February 2014 to July 2014. After all, the results were analyzed based on given categories. The results of this research can be summarized as following. First, the characteristic of the master plan layout in Hanok hotel was appeared as "ㄷ" and "ㅡ" shapes. Those layouts were based on the spatial and the functional aspects of Hanok hotel facilities. Second, three different structural methods such as the korean traditional wooden structure, concrete, and masonry method were used in Hanok hotel construction to deliver the traditional architecture aspects while considering the functionality and convenience of the building. Third, most of Hanok hotels had the limited furniture range. The consideration of using several types of traditional furniture in different rates of the guest rooms help to increase the service quality and customer's satisfaction. Fourth, there were no diversity of using materials and colors in Hanok hotels that only few of them were used to express the traditional look. Fifth, the local characteristics were found in several Hanok hotels. To reflect the local characteristics in Hanok hotel is to construct a suitable environment to fit in nature and also it is easily to convey the local culture to others.

Expression Types and Aesthetic Characteristics of Space Directing at Chanel Fashion Shows (Chanel의 패션쇼에 나타난 공간 연출의 표현 유형과 미적 특성)

  • Kim, Jang-Hyeon;Kim, Young-Sam
    • Journal of the Korean Society of Clothing and Textiles
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    • v.37 no.6
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    • pp.809-826
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    • 2013
  • This study considers types of expression and examines aesthetic characteristics by analyzing images expressed through space directing at Chanel Fashion Shows. The conclusions of this study are as follows. The expression types on space directing at Chanel Fashion Shows are what is presented by distributing huge objects associated with Fashion Shows at the center or back of the stage, integrating several detailed decorative elements while maintaining the morphological characteristics of the runway in a linear form, and utilizing an inartificial place or newly forming the whole stage. The symbolism characteristic was first indicated for the aesthetic characteristics on space directing at Chanel Fashion Shows. Symbolism is indicated through the identification of an implicit meaning towards a specific object. The symbolism was highlighted utilizing elements or stories that have a deep association with Chanel. Second, the characteristic of ecology was expressed through the recognition of the importance of the ecological environment by escaping the harmful practices of civilization such as environmental disasters and human alienation. The expression of visual ecology was emphasized utilizing themes related to environmental disasters or reviving the space of primitive nature. Third, the characteristic of fantasy was shown to express thoughts that originated from the human yearning for the ideal world contrary to an incomplete society. Fantasy was created by the inaccessible object in reality and a change in spatial structure. Fourth, the characteristics of amusement expressed pleasure, which is the instinctive desire truly immanent in a human being. It was natural amusement, which was advocated as freedom through the integration of neutrality, integrating either diverse elements (which are naturally recognized in our daily life) into Fashion Shows or amusement, which expressed newness through utilizing unusual objects in Fashion Shows.