• Title/Summary/Keyword: Closed-Structure

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Estimation of Earth Pressures Acting on Box Structures Buried in Ground (지중에 매설된 박스구조물에 작용하는 토압 산정)

  • Hong, Won-Pyo;Yun, Jung-Mann;Song, Young-Suk
    • Journal of the Korean Geosynthetics Society
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    • v.14 no.2
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    • pp.23-33
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    • 2015
  • The earth pressure acting on underground structure was measured by application of the instrumentation system in the subway construction site constructed by the method of cut-and-cover tunnel. The measured earth pressure was compared with the earth pressure obtained from the existed theoretical equation, and the actual earth pressure diagram acting on the underground structure was investigated. As a result of investigation, the vertical earth pressure is mainly affected by the embankment height, and the lateral earth pressure is significantly affected by whether the existence of earth retaining structures or not. The measured vertical earth pressure is very similar to the theoretical earth pressure proposed by Bierbaumer. The measured lateral earth pressure is closed to the active earth pressure proposed by Rankine rather than the earth pressure at rest. The coefficient of earth pressure in soil deposit layer is about 0.35, and the coefficient in soft rock deposit layer is about 0.21. For design and construction the underground structures, therefore, it is reasonable estimation that the lateral earth pressure acting on structures installed in soil deposit layers is an average value between active earth pressure and earth pressure at rest. In rock deposit layers, the lateral earth pressure acting on structure is an active earth pressure only.

The Structure of Research Article Conclusions in Library and Information Science Journals (문헌정보학 학술지 논문의 결론 구조 분석)

  • Kim, Kapseon
    • Journal of Korean Library and Information Science Society
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    • v.49 no.3
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    • pp.111-132
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    • 2018
  • The purpose of this study was to identify the structure and pattern of conclusions chapters in research articles selected in four representative journals published in Korean LIS. To analyse the structure and pattern five categories and eleven elements drawn from RA conclusions were used such as 'Drawing Attention', 'Summarizing', 'Discussing', 'Applying' and 'Extending'. The Findings are as follows. 'Conclusions' was the most used title of the chapter, and then 'conclusions and suggestions'. The conclusions sections were consisted averagely 4.2 elements. 'Summary of findings' was the most frequently elements, followed by 'summary of research process', 'suggestion of further research' and 'implication'. Also, 'summary of findings' was the most used in lengths. 'Summarizing' was the highest frequency in five categories, followed by 'Extending', and 'Applying'. The dominant first element begun conclusions sections was 'summary of findings' and the final element closed conclusion was 'suggestion of further research'. 'Summary of research process - summary of findings' order was found in the most frequent pattern of conclusions. 'Summary of findings' and 'summary of research processes' in 'Summarizing' were found as essential functions, while other elements, such as significance, 'application', 'limitations' in 'Applying' and 'Extending' were found as optional functions in the conclusions of Korean LIS research articles.

A Research on Value Chain Structure on TV Programs Focused on Means-End Chain theory on News, Drama, and Comedy (텔레비전 프로그램 시청 행위의 가치 사슬 구조 연구 국내 수도권 지역 대학생의 뉴스, 드라마, 코미디 프로그램 시청을 중심으로)

  • Kweon, Sang-Hee;Cha, Min-Kyung
    • Korean journal of communication and information
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    • v.71
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    • pp.194-223
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    • 2015
  • This study explores a value chain structure of TV program including news, drama, and comedy. The purpose of this research focused on factor analysis and the relationship among viewer's program selection motivations. This research explores correlation between personal value and viewing motivation. This study was to identify the value structure of respondent on TV program(news, drama, comedy) based on means-end chain theory. The research used structured APT laddering questions and 251 data was analysed. Through such analysis, category difference by stage and relationship difference were identified and hierarchical value map was compared. There are four different value ladders: first is attributes, functional consequences, psychological consequences, and final value. The result shows that on news program the basic function is viewers are want to visual factor and quickly acquire social news and they pursue a value of personal social relationship. Whereas, on drama program, the viewers are reflected by around person, and they selected a program based on closed related person. In addition, the viewers are influenced by program's social nomination, production's brand in drama, and performer's nomination, producer and program prominence on comedy. The program selection is highly correlated on program selection's credibility, vital energetic life, and social relationship. The results shows that there was no significant difference between low involvement group and high involvement group for main category involvement group respondents.

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Initial Development of Forest Structure and Understory Vegetation after Clear-cut in Pinus densiflora Forest in Southern Gangwon-do Province (강원도 남부 지역에서 소나무림 개벌 후 초기 임분 구조 및 하층식생 발달)

  • Bae, Kwan Ho;Kim, Jun Soo;Lee, Change Seok;Cho, Hyun Je;Lee, Ho Young;Cho, Yong Chan
    • Journal of Korean Society of Forest Science
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    • v.103 no.1
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    • pp.23-29
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    • 2014
  • Open- to closed canopy stage and it's ecological characteristics in vegetation succession are commonly described, but poorly understood in Korea. Vegetation development on structure, environment and understory abundance were studied for 16 yr in post-clearcut Pinus densiflora forests in the southern Gangwon-do province by applying space-for-time approach. We sampled 210 plots (10 for structure and 200 for understory) for four seral stages (1yr, 3yr, 10yr and 16yr). After clear-cut, mean stem density increased gradually to $5,714{\pm}645$ stems/ha after 16 years and mean basal area was also from $5.5{\pm}0.7m^2/ha$ after 10 years and doubled at $10.0{\pm}1.6m^2/ha$ in 16 years. Woody debris and bared soil on the forest floor peaked at 11--- after 10 years and at 10.3--- after 3 years, respectively. In understory mean cover declined with all growth form groups following succession, but in richness, forb specie increased with structural development during 16 years. Our study suggested that overstory development did not suppressed whole understory properties especially in richness, thus appeared to act as a filter selectively constraining the understory characteristics. However only long-term studies are essential for elucidating patterns and processes that cannot be inferred form short-term or space-for-time researches. Strong negative relationship between overstory and understory characteristics in conventional models surely reexamined.

A Study on the Chinese Architectural View Point of Realist Hong Daeyong and Joseon Embassy in Beijing (실학파(實學派) 학인(學人) 홍대용(洪大容)의 중국(中國) 건축관(建築觀)과 북경(北京) 조선관(朝鮮館)에 관한 연구)

  • Han, Dong-Soo
    • Journal of architectural history
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    • v.15 no.1 s.45
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    • pp.29-40
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    • 2006
  • This paper is focused on Damheonseo(湛軒書), an anthology written by Hong Daeyong, and I deal with Chinese Architectural views which he had experienced in his itinerary to Beijing, and the vivid pictures of Joseonkwan (called the Koryo or Joseon Embassy) located in Beijing at that time. He was a scholar of great erudition over astronomy, mathematics, military science, politics, and so on. He was interested in practical sciences at early time, and criticized secular scholars full of vanity who had presented purposeless articles. In his age of 35, Qianlong(乾隆) 30 (1764, Youngjo 41), he, a military escort, accompanied by Hong Uk, Joseon envoy and his uncle. Before his itinerary, he self-studied Chinese. Also, during a long journey he got new experiences and information around each area, deviating his group whenever he had some times. He could get more variant experiences than others because of his character full of curiosity, and his observations from the vivid lives of the time helped us get various views between Chinese and Korean architecture. Likewise, although he denounced Qing(淸) scathingly as a barbarian, he mentioned several points about the characteristics of Chinese architecture at that time. First of all, totally Chinese architecture had strong rational and practical points. Secondly, based on bountiful products, buildings along streets shown in Chinese city had sophisticated compositions, and luxurious and magnificent appearances. Thirdly, using the brick from walls to houses was so universal. Fourthly, the layouts of building with three- or four-closed courtyard had very orderly shapes, and the structure of street was also so arranged. Finally, because of stand-up lives, the scales and appearances of interior space were even more extended, and storages were less developed than those of Joseon. As another points, I found that Joseonkwan was moved next to Shushangguan(庶常館)from Huidongnanguan(會同南館) around Hanlimyuan(翰林院), and had been remodeled into a house with Korean custom in using the inner spaces, although it was followed by a closed courtyard style. Likewise, I recognized that Ondols were sure to be established in all temporary houses during the journey to Qing, and felt their strong traditional residential custom in such mentions. Now that the past pictures have disappeared and ways of life and our values have been largely changed, this study has very important meaning in comparing the ancient Chinese and Korean architecture.

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A research of thermoplastic elastomer PP(Poly Propylene)/SEBS(Styrene Ethylene Butylene Styrene) blends (열가소성 탄성중합체인 PP/SEBS 혼합 연구)

  • Han, Hyun Kak
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.8
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    • pp.562-570
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    • 2018
  • New physical properties of polymer materials were obtained by blending two or three different type of polymers. TPE is used widely in the display, automotive and electronics industries. Consumers have sought emotionally more sensitive and advanced interior automotive parts. A polymer with high foamibility (Ed note: Please check this.) and flowability would be more plausible. TPE composed of foam is a good polymer material to satisfy these trends. In this research, two different TPE were tested, focusing on foamibility and flowability. Two type of TPE were prepared. The first was blended Homo-PP, oil and SEBS. The second was Co-PP, oil and SEBS. The blending temperatures were $180^{\circ}C$, $190^{\circ}C$, and $260^{\circ}C$(second one). The blending speed was 50rpm and blending time was 5 min. The MI of the blended material was affected by the MI of PP and not affected by the blending temperature. The hardness and tensile elasticity were less affected by the MI of PP and blending temperature. The hardness and tensile elasticity were lower at a higher SEBS/Oil content ratio. The soft touch feel was higher with high SEBS/Oil contents. The IPN (Interpenentration polymer network) structure was observed by dissolving the SEBS/Oil layer in xylene. Strain-hardening phenomena also was observed. TPE behaves in a rubber and foamed closed-cell improved its stability.

Synthesis and Characteristics of Highly Oil-absorptive Expanded Polyurethane (고흡유성 발포 폴리우레탄의 합성과 특성)

  • Lee, Yong-Hun;Kim, Wook;Kim, Won-Ho
    • Polymer(Korea)
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    • v.24 no.2
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    • pp.149-158
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    • 2000
  • Oil-absorptive expanded polyurethane (EPU) was prepared with a lypophilic polyol, polypropyleneglycol (PPG) as the soft segment, and toluenediisocyanate (TDI) and $H_2O$ as the hard segment. PPGs haying various average molecular weights ((equation omitted) : 1000, 2000, 3000) were employed to investigate that the soft segment content was consequent on the oil-absorptivity and the mechanical properties of the EPUs. As (equation omitted) of PPG was decreased from 3000 to 1000, the oil-absorptivity and the tensile strength of the EPUs increased from 1460 to 3010% and from 0.26 to 0.55 $kg_{f}$ /$cm^2$ respectively. As the hard segment content ratio, ${\gamma}$ ([NCO]/[OH]) was increased from 1.0 to 1.2, the tensile strength of the EPUs increased from 0.56 to 0.95 $kg_{f}$ /$cm^2$, due to the formation of allophanate and/or biuret bondings. However, as the surfactant (S-A) content was increased from 1.0 to 2.5 pbw, the oil-absorptivity was decreased from 3634 to 3312%, due to the formation of closed cell structures.

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Variations in Plankton Assemblage in a Semi-Closed Chunsu Bay, Korea (반폐쇄적인 천수만 해역의 플랑크톤 군집 변화)

  • Lee, Jae-Kwang;Park, Chul;Lee, Doo-Byoul;Lee, Sang-Woo
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.17 no.2
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    • pp.95-111
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    • 2012
  • Relationship between plankton assemblage and environmental factors in a semi-closed Chunsu Bay was examined. Temporal changes in phytoplankton assemblage was rather drastic than those found in most Korean coastal area in the Yellow Sea primarily due to the seawater temperature (T) and nutrient input from the dikes nearby. Freshwater discharge seemed to cause winter time increase of Diatoms (February) and summer time increase of Dinoflagellates at surface (July to August). Structural change in cell size with time was also found in Diatom. Zooplankton community structure was also changed with season probably due to the food concentration, seawater temperature and salinity (S). From principal component analysis (PCA) of zooplankton distribution, it was postulated that seasonal environmental changes such as T and S could explain about 32% of variability in zooplankton distribution along with phytoplankton cell numbers, while freshwater discharge could explain about 17%. Comparing with past data of 1985-1986, 1991-1992, the distributional patterns and percent composition of major species, Acartia hongi, Paracalanus parvus sensu lato and Centropages abdominalis, were similar. However, the abundances have been increased more than three times. The composition of other taxa than copepods showed significant changes.

Engineering Approach to Crop Production in Space (우주에서 작물 생산을 위한 공학적 접근)

  • Kim Yong-Hyeon
    • Journal of Bio-Environment Control
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    • v.14 no.3
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    • pp.218-231
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    • 2005
  • This paper reviews the engineering approach needed to support humans during their long-term missions in space. This approach includes closed plant production systems under microgravity or low pressure, mass recycling, air revitalization, water purification, waste management, elimination of trace contaminants, lighting, and nutrient delivery systems in controlled ecological life support system (CELSS). Requirements of crops f3r space use are high production, edibility, digestibility, many culinary uses, capability of automation, short stems, and high transpiration. Low pressure on Mars is considered to be a major obstacle for the design of greenhouses fer crop production. However interest in Mars inflatable greenhouse applicable to planetary surface has increased. Structure, internal pressure, material, method of lighting, and shielding are principal design parameters for the inflatable greenhouse. The inflatable greenhouse operating at low pressure can reduce the structural mass and atmosphere leakage rate. Plants growing at reduced pressure show an increasing transpiration rates and a high water loss. Vapor pressure increases as moisture is added to the air through transpiration or evaporation from leaks in the hydroponic system. Fluctuations in vapor pressure will significantly influence total pressure in a closed system. Thus hydroponic systems should be as tight as possible to reduce the quantity of water that evaporates from leaks. And the environmental control system to maintain high relative humidity at low pressure should be developed. The essence of technologies associated with CELSS can support human lift even at extremely harsh conditions such as in deserts, polar regions, and under the ocean on Earth as well as in space.

The Effectiveness of Electroglottographic Parameters in Differential Diagnosis of Laryngeal Cancer (후두암 감별진단에 있어 성문전도(Electroglottograph) 파라미터의 유용성)

  • 송인무;고의경;전경명;권순복;김기련;전계록;김광년;정동근;조철우
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.14 no.1
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    • pp.16-25
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    • 2003
  • Background and Objectives : Electroglottography(EGG) is a non-invasive method of monitoring the vocal cord vibration by measuring the variation of physiological impedance across the vocal folds through the neck skin. It reveals especially the vocal fold contact area and is widely used for basic laryngeal researches, voice analysis and synthesis. The purpose of this study is to investigate the effectiveness of EGG parameters in differential diagnosis of laryngeal cancer. Materials and Methods : The author investigated 10 laryngeal cancer and 25 benign laryngeal disease patients who visited at the Department of Otolaryngology, Pusan National University Hospital. The EGG equipment was devised in the author's Department. Among various parameters of EGG, closed quotient(CQ), speed quotient(SQ), speed index(SI), Jitter, Shimmer, Fo were determined by an analysis program made with MATLAB 6.5$^{\circledR}$(Mathwork, Inc.). In order to differentiate various laryngeal diseases from pathologic voice signals, the author has used the electroglottographic parameters using the neural network of multilayer perceptron structure. Results : SQ, SI, Jitter and Shimmer values except those of CQ and Fo showed remarkable differences between benign and malignant laryngeal disease groups. From the artificial neural network, the percentage of differentiating the laryngeal cancer was over 80% in SQ, SI, Jitter, Shimmer except for CQ and Fo. These results indicated that it is possible to discriminate the benign and malignant laryngeal diseases by EGG parameters using the artificial neural network. Conclusion : If parameters of EGG which can reveal for the pathology of laryngeal diseases are additionally developed and the current classification algorithm is improved, the discrimination of laryngeal cancer will become much more accurate.

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