• Title/Summary/Keyword: 기술적 요소

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Investigating the Monetary Value of Bus Arrival Time Information (실시간 버스도착정보의 가치 측정에 관한 연구)

  • Bin, Mi-Young;Kim, Hyo-Bin
    • Journal of Korean Society of Transportation
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    • v.23 no.6 s.84
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    • pp.81-89
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    • 2005
  • Real-time bus arrival information within the Bus Information System (BIS) is an invaluable resource for users that demand accurate and up-to-date bus headway information while waiting at a bus stop. The associated benefits of such a system come in two folds, that is to 1) resolve the psychological uncertainty caused by the lack of real-time bus arrival information and 2) empower the user waiting at bus stops with the ability to reliably coordinate various tasks and errands, such as a quick trip into a convenience store or restroom without fear of missing a bus pick-up. This paper discusses the appropriate methodology with which to measure the economic value of reliable bus arrival information, with particular emphasis on the psychological uncertainty in users associated with the lack of real-time headway information at bus stops. Data regarding bus transit users' willingness to pay for such a service is obtained through questionnaire surveys, and the Contingent Valuation Method is used to analyze and derive the associated economic value. Our findings indicate the monetary value associated with a real-time bus arrival information system is approximately 132.5 won/min at the 0.3 significance level.

A Study of Targeted Killing, Unmanned Aerial Vehicles (무인항공기 표적살인(Targeted Killing)에 관한 고찰: 논쟁과 실행 정당성을 중심으로)

  • So, Jae-Seon;Lee, Chang-Kyu
    • The Korean Journal of Air & Space Law and Policy
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    • v.32 no.1
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    • pp.53-81
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    • 2017
  • Targeted killing is a modern euphemism for the assassination of an individual by a state organization or institution outside a judicial procedure or a battlefield. Targeted killing using armed drones has raised profound anxieties in legal, policy, and advocacy communities in the United States and abroad, including among UN officials. The bottom line for targeted killing supporters is that targeted killing works as part of a larger counter-terrorism strategy. Targeted killing does what it is supposed to and removes the leader of a group. And despite growing legal, moral, and ethical issues concerning targeted killing, scholars agree that drone strikes and targeted killing operations will stay. The ACLU has sued top CIA and Pentagon decision-makers to seek accountability for the unlawful killings of three U.S. citizens in Yemen last year. Also, strikes by drones are associated with serious problems such as collateral damage to ordinary citizens and friendly fire. Targeted killings by drones also involves several issues to be resolved, including suspicions that they may run counter to domestic law prohibiting assassination, the opacity concerning their definitions and military actions, and the impact of whiplash transition. Finally, targeted killing program and the need for transparency. The assembly referring to resolution invites the committee of ministers to undertake a thorough study of the lawfulness of the use of combat drones for targeted killings and if need be develop guidelines for member states on targeted killings with a special reference to those carried out by combat drones. These guidelines should reflect the states duties under international humanitarian and human rights law in particular the standards laid down in the EC on human rights as interpreted by the european court of human rights.

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Analysis of Structural Work Scheduling of Green Frame - Focusing on Apartment buildings - (Green Frame의 골조공사 공기 분석 연구 - 공동주택을 중심으로 -)

  • Lee, Sung-Ho;Kim, Shin-Eun;Kim, Gwang-Hee;Joo, Jin-Kyu;Kim, Sun-Kuk
    • Journal of the Korea Institute of Building Construction
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    • v.11 no.3
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    • pp.301-309
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    • 2011
  • Apartment housings that adopt a bearing wall structure design, which account for a majority of the housing units available in Korea, are not free from structural constraints that limit the extension of their service life. The resulting need for reconstruction from the ground up requires a massive consumption of resources and energy, and triggers environmental pollution resulting from construction wastes. As a solution to such issues, the government enforces incentive schemes to promote a remodeling-friendly rahmen structure design. Green Frame, which is a novel concept of composite precast concrete structure to support rahmen structure apartment housing buildings, can address the constraints of bearing wall structure and conventional rahmen structure designs that limit the potential for remodeling projects, while reducing the term of construction. Therefore, this study aims to analyze the characteristics of Green Frame and its absolute term of construction, and compare the terms of frame work construction in apartment housing projects adopting different structural design approaches to illuminate their differences. In the end, Green Frame is found to be capable of reducing the term of construction in apartment housing projects. As the term of construction is a very critical element of a construction project, Green Frame will ultimately prove to be one of the key enablers to ensure the success of apartment housing construction projects.

Estimation of Optimal Fare for Cloud Transportation System (클라우드교통시스템의 최적 요금 산정)

  • Ryu, Seong Beom;Bae, Sang Hoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.5
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    • pp.1969-1980
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    • 2013
  • The Traffic congestion is caused by the increasing traffic demand. Thus, economic losses have been increasing every year. To solve these problems, car sharing and rental car systems that are equipped with IT technologies emerge. Car sharing has many advantages-the alleviation of the traffic congestion, the saving of maintenance cost for cars, the reduction of car possessiveness, the solution for the hassle of car ownership, for business and personal duty, and the improvement of connectivity between public transportations-. The goal of the car sharing is to achieve low-carbon and eco-friendly transportation. In this study, we review papers related to the car sharing system and the cost system of traffic systems. We estimate the optimal cost of the cloud traffic system that is one of the car sharing services. We suggest a methodology to estimate operational cost and use cost through the analysis of cost system between similar traffic means. The range of the maximum and minimum cost was determined through the comparison and analysis of similar traffic means. Expected demand and the cost that people are willing to pay were estimated through optimized value pricing. The minimum cost per hour that was compared to the cost of rental car was estimated at 5,333 won and the maximum cost per hour that was compared to taxi cost was estimated at 17,700 won. The cost for users was estimated at 6,930 won. The cost of 50% demands was estimated at 6,550won. Future studies should analyze service hours of users, weather, demand pattern and trend and consider them into the cost estimation.

Computer Simulation for the Thermal Analysis of the Energy Storage Board (에너지 축열보드 열해석을 위한 컴퓨터 수치해석)

  • 강용혁;엄태인;곽희열
    • Journal of Energy Engineering
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    • v.8 no.2
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    • pp.224-232
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    • 1999
  • Latent heat storage system using micro-encapsuled phase change material is effective method for floor heating of house and building. The temperature profile in capsule block and flow rate of hot water are important parameters for the development of heat storage system. In the present study, a mathematical model based on 3-D, non-steady state, Navier-Stokes equations, scalar conservation equations and turbulence model ($\kappa$-$\varepsilon$), is used to predict the temperature profiles in capsule and the velocity vectors in hot water pipe. The multi-block grids and fine grids embedding are used to join the circle in hot water pipe and square in capsule block. The phase change process of the capsule is quite complex not only because the size of phase change material is very small, but also because phase change material is mixed with the cement to form thermal storage block. In calculation, it's assumed that the phenomena of phase change is limited only the thermal properties of phase change material and the change of boundary is not happened in capsule. The purpose of this study is to calculate the temperature profiles in capsule block and velocity vectors in hot water pipe using the numerical calculation. Two kinds of thermal boundary condition were considered, the first (case 1) is the adiabatic condition for the both outside surfaces of the wall, the second (case 2) is the case in which one surface is natural convection with atmosphere and another surface is adaibatic. Calculation results are shown that the temperature profile in capsule block for case 1 is higher than that for case 2 due to less heat loss in adaibatic surface. Specially, in the domain of near Y=0, the difference of temperature is greater in case 1 than in case 2. The detailed experimental data of capsule block on the temperature profile and the thermal properties such as specific heat and coefficient of heat transfer with the various temperature are required to predict more exact phenomena of heat transfer.

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A Study on the Possibility of Using UAV Stereo Image for Measuring Tree Height in Urban Area (도심지역 수목 높이값 측정을 위한 무인항공기에서 취득된 스테레오 영상의 활용 가능성 고찰)

  • Rhee, Sooahm;Kim, Soohyeon;Kim, Taejung
    • Korean Journal of Remote Sensing
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    • v.33 no.6_2
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    • pp.1151-1157
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    • 2017
  • Street Trees is an important object for urban environment improvement. Especially the height of the trees needs to be precisely measured as a factor that greatly influences the removal of air pollutants in the Urban Street Canyons. In this study, we extracted the height of the tree based on the stereo image using the precisely adjusted UAV Images of the target area. The adjustment of UAV image was applied photogrammetric SfM (Structure from motion) based on the collinear condition. We measured the height of the trees on the Street Canyon using stereoscopic vision on stereo plotting system. We also acquired the height of the building adjacent to the street trees and the average height of the road surface was calculated for accurate measurement of the height of each object. Through the visual analysis with the plotting operation system, it was possible to measure height of the tree and to calculate the relative height difference value with building quickly. This means that the height of buildings and trees can be calculated without making a 3D point cloud of UAV and it has the advantage of being able to utilize non-experts. In the future, further studies for semiautomatic/automation of this technique should be performed. The development and research of these technologies is expected to help to understand the current status of environmental policies and roadside trees in urban areas.

An Application of Value Engineering to Design-Build Projects at Design Development Phase (설계${\cdot}$시공일괄 사업의 실시설계단계 VE적용 방안에 관한 연구)

  • Jung Jae-Jin;Kim Jae-Hyun;Koo Kyo-Jin;Hyun Chang-Taek
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.294-298
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    • 2003
  • Recently, Design-build project as delivery system public construction sector tends to be increased according to the Masterplan for promotion of construction technologies, and construction projects are increasing their complexity, variety and scale. And owner's requirements become various. Preliminary design for design eligibility judging of design-build has been designed excessively to get a good point and this tendency includes the elements which is capable of wasting the budget. Because of excessive design, owners require to apply VE study into the design development phase but in the Design-build system, VE application has not been of no effect that owners expect, owing to the characters of lum-sum contracts. The purpose of this study is to propose the plan for effective application of VE in the design development phase in order to solve the problems such as excessive design of preliminary design in the design-build project. This study established plans for VE application through investigating and analyzing VE application case and then proposed the applications in the aspect of regulations and contracts, parties participated in project, VE operation through research for verification of usefulness.

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The Development of Invention Teacher Education Standard - Invention Contents Standards - (발명 교사 교육 표준 개발 -발명 내용학 내용 표준을 중심으로-)

  • Kim, Yong Ig;Choi, Yu Hyun;Noh, Jin Ah;Gang, Jong Pho;Kim, Jee Sook;Nam, Hyen Wook;Moon, Seoung Hwan;You, Young Gil;Lee, Sang Bong;Lee, Myoung Hoon;Lee, Jeoung Guen;Jeoung, Jin Woo;Lim, Yeoun Jin;Lee, Eun Sang
    • 대한공업교육학회지
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    • v.38 no.1
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    • pp.275-297
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    • 2013
  • Invention Teacher Education(ITE) is composed of Invention Contents Standards(ICS) and Invention Education Standards(IES). The purpose of this study is to developing ICS of ITE. To achieve the goal, we used the methods of research; analyzing advanced research, content analysis, development, survey, verify the validity. The research results of this study is summarized as follows. ICS is composed of 10 large areas; the concept and characteristic of invention, invention and society, invetion in living, creativity development, invention and design, invention and solving problem, convergence of knowledge and invention, invention project, intellectual properties and patent application, invention and management of technology. 10 large areas has 20 core contents and 90 subordinate elements. ICS will be based on the academic of developing programming besides it will be reference of standards in the case of progressing invention education.

Finite Element Analysis of RF Coupler in Normal-Low Temperature (상온-저온 RF 커플러 유한요소해석)

  • Kim, Hansol;Lee, Hak Yong;Park, Chan;Lee, Jaeyeol;Lim, Dong Yeal;Yoo, Jeonghoon;Hyun, Myung Wook
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.10
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    • pp.1101-1107
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    • 2014
  • A heavy ion accelerator is a device that accelerates heavy ions in the radio frequency (RF) range. The electric field that flows into the RF cavity continuously accelerates heavy ions in accordance with the phase of the input electromagnetic wave. For the purpose, it is necessary to design a coupler shape that can stably transfer the RF wave into the cavity. The RF coupler in a heavy ion accelerator has a large temperature difference between the input port and output port, which radiates the RF waves. It is necessary to consider the heat deflection on the RF coupler that occurs as a result of the rapid temperature gradient from an ultra-low temperature about 0 K to a room temperature about 300 K. The purpose of this study was to improve the system performance through an analysis of the intensity of the output electric field and temperature distribution considering various shapes of the RF coupler, along with an analysis of the durability considering the heat deflection and heat loss.

Reviews on the Studies of MTBE Contaminants in Groundwater

  • 이지훈;이진용;천정용;이강근
    • Journal of the Korean Society of Groundwater Environment
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    • v.7 no.1
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    • pp.55-58
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    • 2000
  • Methyl tertiary butyl ether (MTBE) is a gasoline additive that boosts the oxygen content in fuel (an oxygenate), resulting in less air-polluting carbon monoxide being released from vehicle exhaust systems. Then, groundwater contamination problems have been developed in areas where the chemical is used. Common sources of water contamination by MTBE include leaking underground gasoline storage tanks and leaks and spills from above ground fuel storage tanks, etc.. Studies on the chemical and these problems are going on abroad vigorously. These studies should be performed in our country as well more actively. This paper reviews on articles on these studies and focuses on the identification of the chemical as a groundwater contamination source.

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