• Title/Summary/Keyword: 계량화부

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Failure Mechanism and Test Method for Reliability Standardization of Solder Joints (솔더조인트의 신뢰성 표준화를 위한 취성파괴 메커니즘 및 평가법 연구)

  • Kim, Kang-Dong;Huh, Seok-Hwan;Jang, Joong-Soon
    • Journal of the Microelectronics and Packaging Society
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    • v.18 no.4
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    • pp.85-90
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    • 2011
  • With regard to reliability of solder joint, the significant failures include open defects that occurs from alignment problem, Head in Pillow by PCB's warpage, the crack of solder by CTE mismatch, and the crack of IMC layer by mechanical impact. Especially as PCB down-sizing and surface finish is under progress, brittle failure of IMC layer between solder bump and PCB pad becomes a big issue. Therefore, it requires enhancing the level of difficulty in the existing assessment method and improving the measurement through the study on the mechanism of IMC formation, growth and brittle failure. Under this circumstance, this study is intended to suggest the direction of research for improving the reliability on the crack such as improvement of IMC brittle fracture.

Accessibility Evaluation of Accredited Certificate Subscriber Software (공인인증서 가입자 소프트웨어의 접근성 평가)

  • Hong, Kyoung-Soon;Choi, Seong-Eun;Kim, Suk-Il
    • The Journal of the Korea Contents Association
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    • v.11 no.2
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    • pp.40-53
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    • 2011
  • This paper proposes methods of evaluating and measuring accessibility of accredited certificate subscriber software which is one of crucial applications to submit personal certifications while web surfing. The presented methodology is to evaluate accessibility by using a certain assessment tool and is to normalize accessibility level into points, so that the software developers who are unfamiliar to screen readers can easily perform accessibility evaluation. The software from the major 78 organizations has went through the assessment. Those of 48 organizations, 62% out of the total, have acquired less than 70 points, implying the software of them is not accessible by the blind. The remaining 18 software got the highest point(88), are partly inaccessible by the blind that uses screen readers. This implies that the proposed methods are applicable to evaluate the accessibility of the software.

Development of Evaluation Items for Self and Peer Assessment of Team Members in Cooperative Learning (협동학습에서 팀 구성원의 자기 및 동료평가를 위한 평가문항 개발)

  • Boo, Sung-Mi;Park, Chan-Jung
    • The Journal of Korean Association of Computer Education
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    • v.6 no.4
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    • pp.1-10
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    • 2003
  • There are various kinds of instructional models in the 7th national curriculum. Among them, cooperative learning is given to students in some schools. In cooperative learning, the items for assessing the team members are required in order to evaluate the individual activities for problem solving, and to know the way of objective thinking each student does. Web-based environment is good for cooperative learning. In this paper, as a previous research work of web-based cooperative learning, we propose new assessment items which are based on the outcome D belongs to the set of 11 student learning outcomes design attributed framework developed by ABET EC-2000 and the cognitive categories defined by Bloom's taxonomy. These assessment items consist of self and peer assessment. The self assessment items include the evidence of the students' thought and their own assessment. On the other hand, the peer assessment can give the students the opportunities to participate in their activities enthusiastically, to offer interactive individual feedbacks, and to develop potential through various experiences.

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Issues and Improvements in Extended Application of LID technologies (국내 LID 기법 적용확대의 문제점 및 개선방안)

  • Choi, Jong-Soo;Hyun, Kyoung-Hak;Lee, Jung-Min;Kang, Myung-Soo;Jung, Seung-Kwon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2012.05a
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    • pp.242-246
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    • 2012
  • 우리나라의 경우 비점오염원에 의한 오염부하 기여도가 점차 증가하면서 '06년 관련 법규 개정을 통해 일정 규모 이상의 개발사업에 대해서는 비점오염저감시설 설치를 의무화하였으며, '11년 기준 국내에는 약 6,000여개 이상의 저감시설이 설치되었다. 해당 시설에 대한 모니터링 결과 장치형에 비해 자연형이 처리효율 및 유지관리 측면에서 유리한 것으로 보고되면서 환경부는 개발사업에 대해 저영향개발기법(LID)의 적용을 의무화하는 방안을 추진 중이다. 개발사업에 있어 LID는 토지이용기법을 통해 우수 유출과 오염원 유출을 저감하고자 하는 기법으로, 비용 및 유지관리 측면에서는 유리하나 기존 단위시설 적용기법에 비해 계획적인 요소가 강해 적용 확대 및 의무화가 용이하지 않은 한계가 있다. 따라서, 본 연구에서는 LID 적용 확대와 관련된 문제점을 분석하고 적용 의무화를 위해 필요한 대안을 모색해 보고자 하였다. 이를 위해 해당 기법 자체가 가지는 한계와 제도적인 문제점을 분석하였으며, LID 기법의 확대 적용을 위해 필요한 대안을 제안하였다. 분석 결과, LID 기법은 기존 장치형 시설에 비해 계획기법의 측면이 커 기술개발이 어려울 뿐만 아니라, 저감시설의 적용여부에 대한 검증도 곤란한 것으로 분석되었다. 또한, 처리효율 계량화가 어려워 오염총량제와 연계된 오염부하 삭감효과 인정이 곤란해 확대 적용에 한계가 있는 것으로 나타났다. 상기의 분석결과에 근거할 때, LID 기법의 확대 적용은 국내의 제도적 여건 및 LID 기법 자체의 한계를 감안하여 단계적으로 추진되어야 할 것으로 판단되며, 조속한 확대 시행을 위해서는 다음의 방안 마련을 제안한다. 첫째, 적용 여부에 대한 판단이 모호한 단점을 보완하기 위해 적정 적용여부를 심의할 수 있는 인증제도 도입을 제안한다. 이 제도는 친환경건축물인증제도 등 기존 유사 제도에 항목을 추가하는 방법과 별도의 제도를 신설하는 방법이 가능할 것이다. 둘째, 처리효율 정량화를 위해 기존 농도 위주의 처리효율 개념을 벗어나 유량 개념의 처리효율 산정이 필요하다. 즉, 처리용량 범위내에서 외부에 유출없이 우수저류 및 침투가 가능한 경우 전량 처리되는 것으로 간주하는 방식이다. 연구결과로 제안한 LID 기법 적용에 대한 인증제도 마련과 유량개념의 처리효율 산정방안이 도입된다면, 보다 조속한 시일내 LID 기법의 확대 적용이 가능할 것이다.

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A Study on Organizational Performance Indicators of IT Company (IT 기업의 조직 성과 지표에 관한 연구)

  • Kim, Hyung-Sub
    • Journal of the Korea Convergence Society
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    • v.10 no.1
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    • pp.187-195
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    • 2019
  • There is a growing emphasis on objective and quantified performance measurement methodologies for the interactions that occur within modern companies. This is due to the importance of establishing and practicing future-oriented strategies by estimating the present value of the company and the current energy status through objective evaluation of the company. Therefore, the selection of KPI as a performance index using BSC (Balance Scorecard), which is a recent objective performance measurement methodology, has become very important. Although many studies on existing KPIs have been made in various industries, KPI studies on SI companies have been insufficient. This study focuses on finding KPIs applicable to SI companies. The study on the KPI design system according to general strategy of SI companies and the development of methodology and evaluation index according to index development for each group were carried out and the weighting methodology according to each evaluation index was presented.

Carbon Storage and Uptake by Deciduous Tree Species for Urban Landscape (도시 낙엽성 조경수종의 탄소저장 및 흡수)

  • Jo, Hyun-Kil;Ahn, Tae-Won
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.5
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    • pp.160-168
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    • 2012
  • This study generated regression models to estimate the carbon storage and uptake from the urban deciduous landscape trees through a direct harvesting method, and established essential information to quantify carbon reduction from urban greenspace. Tree species for the study included Acer palmatum, Zelkova serrata, Prunus yedoensis, and Ginkgo biloba, which are usually planted as urban landscape trees. Tree individuals for each species were sampled reflecting various diameter sizes at a given interval. The study measured biomass for each part including the roots of sample trees to compute the total carbon storage per tree. Annual carbon uptake per tree was quantified by analyzing radial growth rates of stem samples at breast height. The study then derived a regression model easily applicable in estimating carbon storage and uptake per tree for the 4 species by using diameter at breast height(dbh) as an independent variable. All the regression models showed high fitness with $r^2$ values of 0.94~0.99. Carbon storage and uptake per tree and their differences between diameter classes increased as the diameter sizes got larger. The carbon storage and uptake tended to be greatest with Zelkova serrata in the same diameter sizes, followed by Prunus yedoensis and Ginkgo biloba in order. A Zelkova serrata tree with 15cm in dbh stored about 54kg of carbon and annually sequestered 7 kg, based on a regression model for the species. The study has broken new grounds to overcome limitations of the past studies which substituted, due to a difficulty in direct cutting and root digging of urban landscape trees, coefficients from the forest trees such as biomass expansion factors, ratios of below ground/above ground biomass, and diameter growth rates. Study results can be useful as a tool or skill to evaluate carbon reduction by landscape trees in urban greenspace projects of the government.

The Economic Assessment of Claims for Oil Pollution Damages : The Canadian Experience (유류해양오염으로 인한 환경피해에 대한 경제적 가치평가: 캐나다의 유류해양오염에 대한 사례연구)

  • Jung, Hyung-Chan
    • The Journal of Fisheries Business Administration
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    • v.34 no.1
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    • pp.157-183
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    • 2003
  • 유류오염 사고를 사전에 예방할 수 있는 정책 수단으로는 여러 가지가 있지만 주요한 것으로는 인센티브제의 활용을 들 수 있다. 유류오염 사고를 예방하고 관리하기 위한 인센티브는 유출 사고로 인해 발생한 해양자원의 피해에 대해 가해자에게 배상책임(liability for losses due to spills)을 부과함으로써 제공될 수 있다. 유류오염 사고로 인한 피해액을 실제 화폐단위로 계량화하는 작업은 배상책임 부과제도를 정책수단으로 활용하기 위해 해결해야 할 가장 어려운 과제이다. 따라서, 최근 미국과 캐나다를 중심으로 발전하고 있는 자연자원 피해에 대한 가치 평가법(Natural Resource Damage Assessment : NRDA)은 배상책임 부과제도를 정책적으로 보완할 수 있는 이론적 도구로 간주되고 있다. NRDA는 잠재적인 가해자들에게 그들이 자연환경을 보존해야 하는 사회적 의무를 이행하지 못하고 이를 훼손하게 될 때 이로 인해 발생하는 모든 사회적 비용을 직접 부담해야 한다는 명확한 재무적 인센티브(financial incentive)를 부여함으로써 가해자 보상 원칙 (polluter pays principle)을 실현 할 수 있게 한다. 본 연구는, 유류오염 사고로 인한 환경자원 피해의 경제적 가치를 추정하는 가장 중요한 이론적 모형으로 활용되고 있는 가상상황평가법(CVM)에 대한 기초 개념과 이론적 체계, 그리고 이를 실제 피해액 추정에 성공적으로 적용시키기 위해 해결해야 할 문제점 등을 다루었다. 이를 위해, 본 연구에서는 1988년 캐나다 북서부 연안에서 발생한 Nestucca 유류오염 사고를 사례연구의 대상으로 선정하고, 사고 당시 캐나다 연방정부와 British Columbia 주정부를 대신하여 해양오염에 의한 환경피해의 경제적 가치를 추정한 미국의 컨설팅 회사인 RCG/Hagler, Baily Inc.의 가상상황평가법(CVM) 적용 사례를 분석 검토하였다. Nestucca 사례연구에서는 이들 연구자들이 실제로 활용한 설문지 설계, 설문방법 및 표본설계 등을 분석하였으며, 또한 CVM이 본질적으로 갖고 있는 방법론적 문제점들을 연구자들이 어떻게 해결하려고 했는가를 고찰하였다. 그리고, WTP 추정을 위해 RCG 연구자들이 사용한 사전규제접근법(ex ante regulatory approach)으로 인해 야기될 수 있는 환경자원 피해액 추정 방법의 한계점도 함께 검토하였다. 캐나다 연방정부와 British Columbia 주정부는 Nestucca 유류오염 사고로 인한 자연 자원 피해에 대한 손해배상으로 $4.3 Million의 보상금을 지급 받게 된다. 캐나다 정부는 이 보상금으로 Nestucca Oil Spill Trust Fund를 설립하여 피해를 입은 자연자원의 원상회복(restoration)을 위한 다양한 연구 프로젝트에 자금을 지원하고 있다. Nestucca 유류오염 사고를 계기로 캐나다 정부와 학계는 해양자원의 피해에 대한 경제적 가치평가와 자원의 원상회복에 대한 체계적인 접근 방안을 처음으로 마련 시행하게 되었다는 점에서, Nestucca 유류오염 사고에 대한 사례연구는 캐나다의 해양환경 보존 정책을 연구하는 출발점으로 평가될 수 있을 것이다. 이에 비해, 우리나라에서 대표적인 유류오염사고로 알려져 있는 시프린스호 사고와 관련된 손해배상금은 주로 연안어민들의 어업피해 배상으로 이루어져 있으며, 간접피해에 대한 배상액 48억 5천만원도 대부분 치어방류, 여수대학교 종묘배양장건립 등 피해지역 연안어업 발전을 위한 사업에 투자되었다.

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A Study on the Model Development and Empirical Application for the Effectiveness Verification of Domestic Seaport Investment (국내항만투자의 유효성 검증을 위한 모형개발 및 실증적 적용에 관한 연구)

  • Park, No-Gyeong
    • Journal of Korea Port Economic Association
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    • v.24 no.2
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    • pp.209-239
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    • 2008
  • The purpose of this paper is to investigate the effectiveness of Korean port investment by using the newly developed slack-based multi-year panel congestion model of DEA(Data Envelopment Analysis). Inputs[port investment amount, cargo handling capacity, and berthing capacity], and outputs[cargo handling amount, number of ship calls, revenue, and score of customer service satisfaction] are used during 1994-2004 for 20 Korean seaports. Empirical analysis identified congestion especially in port investment as input at the ports of Gunsan, and Busan in the all 3 models, and the ports of Pyungtag, Mogpo, Yeosu, and leju in over 2 models. Port investment induced the rapid increase of port efficiency from the ports of Masan, Incheon, Donghae, and Samcheok. Therefore other ports except these ports should examine the reason about the inefficiency of port investment by searching out the situation of each ports directly. The main policy implication based on the findings of this study is that The Ministry of Land, Transport and Maritime Affairs in Korea should introduce the new measurement way after reviewing the multi-year slack-based congestion approach when the amount of port investment for each port is decided.

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Estimation of Hi-pass Traffic Dispersion Rates to Determine The Optimal Location of Hi-pass Lanes at A Toll Plaza (요금소 하이패스 차로 배치 최적화를 위한 하이패스 차량 교통분산율 추정)

  • Lee, Jaesoo;Lee, Ki-Young;Lee, Cheol-Ki;Yun, Ilsoo;Yu, Jeong Whon
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.12 no.4
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    • pp.22-32
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    • 2013
  • Since the percentage of vehicles equipped with Hi-pass, an electronic toll collecting device, has increased rapidly, it is very crucial to determine the optimal location of Hi-pass lanes at a toll plaza in terms of traffic control and operation. In this study, the appropriateness of existing Hi-pass lanes of a toll plaza is evaluated considering its physical geometry and traffic characteristics. A new evaluating criterion called "traffic dispersion rate" is developed in order to measure the level of traffic spreading across the toll booth lanes at a toll plaza. Logistic regression models are constructed to estimate the relationship between the traffic dispersion rate and its affecting variables. The model estimation results show that several variables including Hi-pass lane traffic volume, length of toll plaza, entering/exiting taper lengths, and locations of Hi-pass lanes. The results also suggest that traffic dispersion rate can be increased by adjusting the location of Hi-pass lanes. The study enables us to quantify traffic dispersion rate which can be used to optimize the location and operation of Hi-pass lanes at toll plazas.

Clonal Variation of Flowering in Pinus thunbergii Seed Orchard (해송 채종원(採種園)에서 개화특성(開花特性)의 클론 변이(變異))

  • Han, Sang-Urk;Choi, Wan-Yong;Chang, Kyong-Hwan;Kim, Tae-Su;Song, Jeong-Ho
    • Journal of Korean Society of Forest Science
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    • v.90 no.6
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    • pp.717-724
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    • 2001
  • This study was conducted in an attempt to quantify some traits that may be involved in the reproductive process of Pinus thunbergii. During the past 6 years (1995-2000), we surveyed flowering patterns of 60 P. thunbergii clones in a seed orchard which was established in Anmyon-do, 1979. From this survey, we estimated clonal contributions of male and female flowers and sexual asymmetry. Among 60 clones, 18 clones (30%) accounted for 0.37 (1999)~0.46 (1995) of clonal contribution in female flowers and 0.44 (1999)~0.57 (1995) of clonal contribution in male flowers. As compared with the previous reports in other pine species, more clones made contributions to reproductive process in P. thunbergii seed orchard. The relative effective population numbers for females (v♀) varied from 0.59 (1995) to 0.91 (1999) and those for males ( v♂) were between 0.56 (1995) and 0.83 (1998) at gamete level. This showed that the female gametes effectively contribute to the reproductive process more than did the male gametes. The relative effective population numbers at clonal level ($v_b$) were in the range of 0.72 (1995) and 0.93 (1999). More than 73% of the total clones showed values of 0.4~0.6 ($0.5{\pm}0.1$) in maleness index. The values averaged over all the clones were temporally variable with the range of 73% in 1996 and 100% in 2000. The degree of sexual asymmetry ($A_s$) ranged from 0.09 to 0.26. These values were relatively low when compared with those of other trees, suggesting that P. thunbergii seed orchard remains a high level of homogeneity in the number of male and female. All of the various types of effective population numbers were positively correlated with each other while they were negatively correlated with the degree of sexual asymmetry.

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