• Title/Summary/Keyword: 대형요소

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A Study on The Enhancement of Aviation Safety in Airport Planning & Construction from a Legal Perspective (공항개발계획과 사업에서의 항공안전성 제고에 대한 법률적 소고)

  • Kim, Tae-Han
    • The Korean Journal of Air & Space Law and Policy
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    • v.27 no.2
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    • pp.67-106
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    • 2012
  • Today air traffic at the airport is complicated including a significant increase in the volume of air transport, so aviation accidents are constantly occurring. Therefore, we should newly recognize importance of the Air Traffic Safety, the core values of the Air Traffic. The location of airport that is the basic infrastructure of the air traffic and the security of safety for facilities and equipments are more important than what you can. From this dimension, I analyze the step-by-step safety factors that are taken into account in the airport development projects from the construction or improvement of the airport within the current laws and institutions and give my opinion on the enhancement of safety in the design and construction of airport. The safety of air traffic, as well as airport, depends on location, development, design, construction, inspection and management of the airport including airport facilities because we have to carry out the national responsibility that prevents the risk of large social overhead capital for many and unspecified persons in modern society through legislation regarding intervention of specialists and locational criteria for aviation safety from the planning stage of airport development. In addition, well-defined installation standards of airports and air navigation facilities, the key points of the airport development phase, can ensure the safety of the airport and airport facilities. Of course, the installation standards of airport and air navigation facilities are based on the global standard due to the nature of air traffic. However, to prevent the chaos for the safety standards in design, construction, inspection of them and to ensure the aviation safety, the safety standards must be further subdivided in the course of domestic legislation. The criteria for installation of the Air Navigation facilities is regulated most specifically. However, to ensure the safety of the operation for Air Navigation Facilities, performance system proved suitable for the Safety of Air Navigation Facilities must change over from arbitrary restrictions to mandatory restrictions and be applied for foreign producers as well as domestic producers. Of course, negligence of pilots and defective aircraft maintenance lead to a large portion of the aviation accidents. However, I think that air traffic accidents can be reduced if the airport or airport facility is perfect enough to ensure the safety. Therefore, legal and institutional supplement to prioritize the aviation safety from the stage of airport development may be necessary.

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An Experimental Study on Real Time CO Concentration Measurement of Combustion Gas in LPG/Air Flame Using TDLAS (TDLAS를 이용한 LPG/공기 화염 연소가스의 실시간 CO 농도 측정에 관한 연구)

  • So, Sunghyun;Park, Daegeun;Park, Jiyeon;Song, Aran;Jeong, Nakwon;Yoo, Miyeon;Hwang, Jungho;Lee, Changyeop
    • Clean Technology
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    • v.25 no.4
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    • pp.316-323
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    • 2019
  • In order to enhance combustion efficiency and reduce atmosphere pollutants, it is essential to measure carbon monoxide (CO) concentration precisely in combustion exhaust. CO is the important gas species regarding pollutant emission and incomplete combustion because it can trade off with NOx and increase rapidly when incomplete combustion occurs. In the case of a steel annealing system, CO is generated intentionally to maintain the deoxidation atmosphere. However, it is difficult to measure the CO concentration in a combustion environment in real-time, because of unsteady combustion reactions and harsh environment. Tunable Diode Laser Absorption Spectroscopy (TDLAS), which is an optical measurement method, is highly attractive for measuring the concentration of certain gas species, temperature, velocity, and pressure in a combustion environment. TDLAS has several advantages such as sensitive, non-invasive, and fast response, and in-situ measurement capability. In this study, a combustion system is designed to control the equivalence ratio. Also, the combustion exhaust gases are produced in a Liquefied Petroleum Gas (LPG)/air flame. Measurement of CO concentration according to the change of equivalence ratio is confirmed through TDLAS method and compared with the simulation based on Voigt function. In order to measure the CO concentration without interference from other combustion products, a near-infrared laser at 4300.6 cm-1 was selected.

A Study on the Application of RTLS Technology for the Automation of Spray-Applied Fire Resistive Covering Work (뿜칠내화피복 작업 자동화시스템을 위한 RTLS 기술 적용에 관한 연구)

  • Kim, Kyoon-Tai
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.5
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    • pp.79-86
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    • 2009
  • In a steel structure, spray-applied fire resistive materials are crucial in preventing structural strength from being weakened in the event of a fire. The quality control of such materials, however, is difficult for manual workers, who can frequently be in short supply. These skilled workers are also very likely to be exposed to environmental hazards. Problems with construction work such as this, which are specifically the difficulty of achieving quality control and the dangerous nature of the work itself, can be solved to some degree by the introduction of automated equipment. It is, however, very difficult to automate the work process, from operation to the selection of a location for the equipment, as the environment of a construction site has not yet been structured to accommodate automation. This is a fundamental study on the possibility of the automation of spray-applied fire resistive coating work. In this study, the linkability of the cutting-edge RTLS to an automation system is reviewed, and a scenario for the automation of spray-applied fire resistive coating work and system composition is presented. The system suggested in this study is still in a conceptual stage, and as such, there are many restrictions still to be resolved. Despite this fact, automation is expected to have good effectiveness in terms of preventing fire from spreading by maintaining a certain level of strength at a high temperature when a fire occurs, as it maintains the thickness of the fire-resistive coating at a specified level, and secures the integrity of the coating with the steel structure, thereby enhancing the fire-resistive performance. It also expected that if future research is conducted in this area in relation to a cutting-edge monitoring TRS, such as the ubiquitous sensor network (USN) and/or building information model (BIM), it will contribute to raising the level of construction automation in Korea, reducing costs through the systematic and efficient management of construction resources, shortening construction periods, and implementing more precise construction

Effects of Water Table Depth in Different Soil Texture on Growth and Yield of Barley and Wheat (토성별 지하수위가 밀, 보리의 생육 및 수량에 미치는 영향)

  • 이홍석;박의호;송현숙;구자환
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.40 no.2
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    • pp.195-202
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    • 1995
  • This experiment was performed to characterize the optimum water table level for the growth and yield of barley(var. Olbori) and wheat(var, Grumil), Olbori and Grumil were grown in the 550 liter plastic pot filled with silt loam or sandy loam, During the whole growth period, the water table adjusted to be 20, 30, 40, 50, and 70cm, Higher water table was resulted in the decrease in plant height and top dry weight, but in the increase of the ratio of top to root dry weight, especially in barley, This suggested that high water table level affected more the growth of top than that of root, The number and area of green leaves were decreased as the water table was higher than 30 to 40cm at the late growth period(May 18, 1993), The largest number and area of green leaves were shown at 50cm of water table in sandy loam and at 70cm in silt loam, As the water table was high, the leaf chlorophyll content was low, And barley was affected more significantly than wheat by soil texture, The photosynthetic activity was decreased remarkably at 20cm water table, Heading period was 2 to 3 and 4 days earlier at the 20cm water table of sandy loam in barley and wheat, respectively, However this earlier heading was not shown in silt loam, Grain filling was accelerated 5 to 7 days earlier in barley and 10 days in wheat grown at 20cm water table, The highest yield was present at 50 and 70cm water table, The yield was decreased remarkably at 20cm water table, resulting that yield reduction ratio of barley was 71.1% and 72, 2%, and that of wheat was 41.0% and 60, 0% in sandy loam and silt loam, respectively, High water table decreased the number of spike per unit area, but increased the seed weight per spike in barley, However, High water table reduced the seed weight per spike in wheat. There was significant correlation between yield and leaf chlorophyll content in wheat and barley, Yield was correlated significantly with green leaf area in barley, and with top dry weight, ratio of top to root dry weight chlorophyll content and photosynthetic activity in wheat. The optimum water table was 50 to 70cm in wheat and barley, They grew fairly well at 30cm water table of sandy loam, and at 40cm of silt loam.

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Misconceptions of the Freshmen at High School about Plate Tectonics (판구조론에 관한 고등학교 1학년 학생들의 오개념)

  • Jeong, Kyoung-Jin;Jeong, Ku-Song;Moon, Byoung-Chan;Jeong, Jin-Woo
    • Journal of the Korean earth science society
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    • v.28 no.7
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    • pp.762-774
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    • 2007
  • The purpose of this study was to investigate misconceptions about plate tectonics which spread widely among freshmen at high school with drawing. For this, we chose 6 conceptions about plate tectonics by analysis of 7th curriculum and of 11 kinds of science textbooks. Questionnaire of drawing about plate tectonics were developed depending on them. Data was collected from 134 students who was freshmen at high school in Daegu. The result of this study was as follows. First, In structure of plate, 'upper mantle type' and 'crust type' misconceptions were more than half of the respondents. Second, In distribution of plate, 'cracked earthquake zone type' and 'earthquake frequency type' misconceptions were more than half of the respondents. Third, In formation of ocean ridge at oceanic crust- oceanic crust divergent plate boundary, 'divergence type' and 'collision type' misconceptions were more than half of the respondents. Fourth, In formation of mountain ridge at continental crust- continental crust convergent plate boundary, 'collision type' misconceptions were more than half of the respondents. Fifih, In formation of mountain ridge at oceanic crust- continental crust convergent plate boundary, 'subduction type' and 'fault type' misconceptions were more than half of the respondents. Sixth, In transform-fault at oceanic crust- oceanic crust transform-fault boundary, 'direction type' and 'section type' misconceptions were almost half of the respondents. In this study, students' drawings about plate tectonics showed similar misconceptions. This imply that drawing conceptions can be used by the strong evidence of misconceptions which spread widely among students. Furthermore, this study has a significance that this conclusion is useful to teachers as basic teaching-teaming materials of plate tectonics.

Development of a Dynamic Offtracking Model on Horizontal Curve Sections (Based on Articulated Vehicles) (도로 평면곡선부에서 동적궤도이탈모형 개발에 관한 연구 (굴절차량을 중심으로))

  • 최재성;김우현
    • Journal of Korean Society of Transportation
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    • v.20 no.3
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    • pp.115-128
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    • 2002
  • Dislike the tangent sections, the horizontal curve sections of roads should be designed, considering several factors : one of such factors is widening. In other words, since widening results from that when a vehicle runs on the horizontal curve sections, the rear wheels of the vehicle run not along with tracks of the front wheels but out of that, such offtracking should be exactly investigated and reflected in design of the curve sections. Especially in the case of industrial roads which semi-trailers and large trucks run frequently or arterial roads with small curve radiuses in mountainous regions. serious offtracking Phenomenons result in increasing the risk of accidents. decreasing the capacities and jeopardizing pedestrians' safety on the curve sections. For the offtracking, widening amounts of roads has been determined under the traditional presumption that vehicles run at a low speed and there is no superelevation. In fact, however, since the vehicles run at a high speed as well as at a low speed and the superelevation is installed on the horizontal curve sections in the structural aspect of roads, the existing standards for installing widening have a limitation to reflect exactly actual Phenomenons. In particular, for articulated wheel axles of a tractor and a trailer and long articulated vehicles, not only the offtracking degree is very high but also the interpretation shows different aspects from one of single axles. Comparing and reviewing the results of Korean and foreign studies related to the trailer offtracking model theory and the standards for installing widening, this study developed a realistic dynamic offtracking model which considers geometric structures of roads and speeds of vehicles, suggested how to measure widening with this model and examined applicability of the model. The findings of this study are as follows ; First. a dynamic offtracking model. which considers dynamic movements of a tractor and a trailer and the superelevation, was developed. Second, a new method to measure widening with the developed dynamic offtracking model was developed and a method to measure widening with swept path width was suggested as well. Finally, validity of the current standards for installing widening was examined by determining actual offtracking and widening amounts with the developed model and the applicability was investigated through the case studies. Compared with the existing offtracking models, the dynamic offtracking model developed in this study can reflect practically vehicle speed. dimension and geometric structural aspects of roads. In conclusion, the meaning of this study is that it reviews validity of the current standards for installing widening and provides a base to establish such standards by suggesting new methods to measure the widening with this dynamic offtracking model.

Design of Truck Escape Ramps (자동차 긴급 피난 차선의 계획 설계)

  • 구본충
    • Journal of the Korean Professional Engineers Association
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    • v.28 no.4
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    • pp.54-75
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    • 1995
  • This synthesis has been prepared from a review of literature on Truck Escape Ramps technology and a survey of current practice by state department of transportation. Their locations have been determined usually from a combination of accident experience and en-gineering judgement, but new tools are emerging that can identify needs and sites without waiting for catastrophic accidents to happen. The Grade Severity Rating Systems holds promise in this regard. Design Procedures for truck excape ramps continue to evolve. Gravel arrester beds are clearly the preferred choice across the country Rounded aggregate, uniformly graded in the approximate size range of 13 to 18mm. Tech-nical publications typically have dassified TER types as paved gravity, sandpile, and ar-rester bed ramps. The design speed for vehicle entry into the ramp in critical to the deter-mination of ramp length. An escape ramp should be designed for a minimum entry speed of 130km/hr, a 145km/hr design being preferred. The ramps should be straight and their angle to the roadway align-ment should be as possible. The grade of truck escape ramps show the adjustment of ramp design to local topography, such as the tradeoff of ramp length against earthwork requirements. A width of 9 to 12m would more safety acommodate two or more outof con-trol vehicles. Reguarding comments on the most effective material, most respondents cited their own specification or referred to single graded, rounded pea gravel. The consensus essentially Is that single graded, well -rounded gravel is the most desirable material for use in arrester beds. The arrester beds should be constructed with a minimum aggregate depth of 30cm. Successful ramps have used depths between 30 and 90cm.

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The Roles of Shop Owners in Boosting Conventional Markets (상권활성화에 있어서 상업자의 역할에 관한 연구)

  • Park, Seung-Je
    • Journal of Distribution Science
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    • v.9 no.4
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    • pp.93-102
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    • 2011
  • With the increasing interest in boosting conventional markets, many authors have paid considerable attention to the roles of shop owners, store image improvement, and how to attract or maintain customers. Nevertheless, it is not easy to find papers related to the relationship between shop owners and their contribution to trading areas, directly or indirectly, in the academic world. Accordingly, research for answering the following question has been initiated: what kind of roles do shopkeepers should play in revitalizing poor conventional markets? Based on the previous studies focusing on enhancing traditional markets, this research was approached from the new insights that have been obtained concerning how to boost conventional markets, that is, from the perspectives of a shop owner and a trader. Therefore, this research aims at identifying some resolutions associated with the roles of shop owners to enhance a shopping district in a specific area, classifying their business roles into a few categories, depending on the degree of their participation in improving the shopping environment. Compared with previous studies focusing on emphasizing the importance of improving customer services from a shopkeeper's perspective, this research provides a new insight as far as how to boost conventional markets. It is, furthermore, necessary to note how market participants, particularly shop owners as they are the key players, can contribute to rebuilding their business area together with their customers. As a research technique for effectively achieving the research goal, the authors adopted a documentation methodology based on a large amount of the existing literature for studying how to rebuild traditional markets. Concerned about the ways to revitalize conventional markets, many authors have proposed a variety of strategies, and have suggested more detailed action plans from a practitioner's perspective. By analyzing these research results, the authors will have accomplished the research aim. Rather than simply identifying the roles of shop owners, the author found that they had to understand their social contribution for enhancing their trading areas, as well as their functional roles, in forming a regional society. The conventional market should be, thus, regarded as the place to share regional culture. Consequently, the authors draw some conclusions from the research results. In order to answer the above question, it was found that the roles of shop owners have been considered as one of the most important ways for revitalizing traditional markets. With respect to their roles, it is evident that their business activities are closely related to the improvement of the trading area in terms of sociality, regional development, and market revitalization, by selling products or services to the customers visiting that area. In a word, this implies that shop owners have to actively take part in boosting conventional markets as a core player. Although the authors have properly achieved the research aim, this study has a limitation, like most other research, in adopting a documentation method. Because the research is based on existing data results provided by the prior research conducted a long time ago, whether the research findings are applicable in a contemporary market should be re-examined in future research from a practitioner's perspective, rather than from an academic's perspective.

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Opportunity Tree Framework Design For Optimization of Software Development Project Performance (소프트웨어 개발 프로젝트 성능의 최적화를 위한 Opportunity Tree 모델 설계)

  • Song Ki-Won;Lee Kyung-Whan
    • The KIPS Transactions:PartD
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    • v.12D no.3 s.99
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    • pp.417-428
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    • 2005
  • Today, IT organizations perform projects with vision related to marketing and financial profit. The objective of realizing the vision is to improve the project performing ability in terms of QCD. Organizations have made a lot of efforts to achieve this objective through process improvement. Large companies such as IBM, Ford, and GE have made over $80\%$ of success through business process re-engineering using information technology instead of business improvement effect by computers. It is important to collect, analyze and manage the data on performed projects to achieve the objective, but quantitative measurement is difficult as software is invisible and the effect and efficiency caused by process change are not visibly identified. Therefore, it is not easy to extract the strategy of improvement. This paper measures and analyzes the project performance, focusing on organizations' external effectiveness and internal efficiency (Qualify, Delivery, Cycle time, and Waste). Based on the measured project performance scores, an OT (Opportunity Tree) model was designed for optimizing the project performance. The process of design is as follows. First, meta data are derived from projects and analyzed by quantitative GQM(Goal-Question-Metric) questionnaire. Then, the project performance model is designed with the data obtained from the quantitative GQM questionnaire and organization's performance score for each area is calculated. The value is revised by integrating the measured scores by area vision weights from all stakeholders (CEO, middle-class managers, developer, investor, and custom). Through this, routes for improvement are presented and an optimized improvement method is suggested. Existing methods to improve software process have been highly effective in division of processes' but somewhat unsatisfactory in structural function to develop and systemically manage strategies by applying the processes to Projects. The proposed OT model provides a solution to this problem. The OT model is useful to provide an optimal improvement method in line with organization's goals and can reduce risks which may occur in the course of improving process if it is applied with proposed methods. In addition, satisfaction about the improvement strategy can be improved by obtaining input about vision weight from all stakeholders through the qualitative questionnaire and by reflecting it to the calculation. The OT is also useful to optimize the expansion of market and financial performance by controlling the ability of Quality, Delivery, Cycle time, and Waste.

Influence of Nitrogen Level on the Accumulation of NO3- on Edible Parts of Chinese Cabbage, Radish and Cucumber (질소시비량(窒素施肥量)이 배추, 무우 및 오이의 가식부위내(可食部位內) NO3- 집적(集積)에 미치는 영향(影響))

  • Sohn, Sang-Mok;Oh, Kyeong-Seok
    • Korean Journal of Soil Science and Fertilizer
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    • v.26 no.1
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    • pp.10-19
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    • 1993
  • This study reports the influence of nitrogen application on the yield and the accumulation of $NO_3{^-}$ in edible parts of major vegetables in a pot experiment treated with five levels(0, 1, 2, 4, 8g N/pot) of nitrogen. In the $NO_3{^-}$ accumulation of chinese cabbage the outer leaf were superior to the inner leaf. The $NO_3{^-}$ contents of the midrib in outer and inner leaf were higher than those of the leaf blade. By increasing the nitrogen application, the accumulationsgap in $NO_3{^-}$ accumulation between midrib and leaf blade in a leaf, became larger. The difference ratio of $NO_3{^-}$ accumulation in the outer leaf reached 4.8:1 at 8g N/pot treatment. In theradish, the $NO_3{^-}$ accumulation in the aerial root parts is higher than those of the underground root parts, and it is higher in the leaf than in the petiole. The accumulation of $NO_3{^-}$ in sarcocarp of cucumber was increased along with the added amount of nitrogen, but contents of $NO_3{^-}$ in the core of the cucumber showed no differences in the treatment levels. The $NO_3{^-}$ accumulation differences of outer sarcocarp vs. inner core parts in cucumber was increased along with the higher nitrogen levels, and its difference ratio of $NO_3{^-}$ accumulation reached 13.1:1 at 8g N/pot treatment. The highest $NO_3{^-}$ accumulation in edible parts of chinese cabbage, radish and cucumber were found at the 8g N/pot treatment, and were 3,664ppm in the outer leaf midrib of chinese cabbage, 3,449ppm in the aerial part of root of radish, and 484ppm in sarcocarp part of cucumber. Compared with the control each 130 times, 40.8 times, 20.9 times, respectively. There are positive correlation coefficients between the amount of nitrogen fertilization, $NO_3{^-}$ accumulation in the edible parts, yield, and yield components of edible parts.

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