• 제목/요약/키워드: Test & Evaluation Process

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EIS를 활용한 철근 부식에 따른 콘크리트 손상 모니터링 (Monitoring of Concrete Deterioration Caused by Steel Corrosion using Electrochemical Impedance Spectroscopy(EIS))

  • 우성엽;김제경;이정재;기성훈
    • 한국건축시공학회지
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    • 제22권6호
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    • pp.651-662
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    • 2022
  • 이 연구에서는 전기화학적 임피던스분광법(Electrochemical Impedance Spectroscopy, EIS)을 활용하여 콘크리트 속 철근 부식의 개시, 전파 및 이로 인한 콘크리트의 손상을 관찰하기 위한 실험을 수행하였다. 먼저, 직경 25mm, 높이 70mm 원주형 콘크리트 실험체 중심에 지름 5mm의 탄소강봉을 매입한 실험체를 제작하였다. 실험체에 사용된 콘크리트는 물-시멘트 비 0.4, 0.5, 0.6을 갖는 세 가지 배합을 제작하였다. 촉진부식시험을 수행하여 위하여 철근 콘크리트 실험체는 0.5M NaCl 수용액에 침지한 후 0C, 13C, 65C, 130C의 네 가지 수준의 전하량을 인가하였다. 이 연구에서는 부식촉진 및 이 과정에서 EIS의 주기적 모니터링을 자동화하여 실험의 효율을 향상시켰다. 이 연구의 실험 결과를 통하여 EIS 주요 특성인자를 활용하여 콘크리트 속 철근의 부식상태를 효과적으로 평가할 수 있음을 확인하였다. 전하이동저항(Rc)값은 전하인가량이 0C에서 13C로 증가함에 따라 급격히 감소하여 대략 10kΩcm2 값을 나타내었다. 하지만 부식개시 이후 전하인가량을 13C에서 130C로 증가하였을 때 Rc값의 민감도는 현저히 감소하는 것을 확인하였다. 한편 이중층용량값(Cdl)값은 전하인가량이 0C에서 130C로 증가함에 따라 대략 50×10-6μF/cm2 에서 250×10-6μF/cm2 수준으로 선형비례관계를 보였다. 이러한 결과는 Cdl 모니터링을 통하여 부식물질에 팽창에 따라 유발된 콘크리트 내부 손상의 진전을 효과적으로 평가할 수 있음을 보여준다. 이 연구의 결과는 EIS를 활용하여 콘크리트 속 철근 부식의 확산 및 이에 따른 콘크리트 손상의 실시간 모니터링을 위한 매입형 센서 및 EIS 신호 분석방법의 고도화를 위한 기본 데이터를 제공하는데 의미가 있다.

폐 MgO-C계 내화재의 전기로(EAF) 제강 Flux용 경소돌로마이트 대체 사용 연구 (A Study on the Replacement of a Light Burnt Dolomite with a Waste MgO-C Refractory Material for a Steel-Making Flux in Electric Arc Furnace)

  • 김현종;임종덕;김행구;왕제필
    • 자원리싸이클링
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    • 제31권6호
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    • pp.44-51
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    • 2022
  • 현재 전기로(EAF) 제강 공정에서는 내화재 보호 및 탈황능 개선을 위해 MgO 함유 Flux인 경소돌로마이트를 사용하고 있으며, 탈산 효과와 동시에 Slag foaming을 통한 전력에너지를 저감시키기 위해 가탄제를 투입하고 있다. 본 연구에서는 상기 효과들을 경제적으로 달성하기 위해 폐 MgO-C계 내화재를 사용하고자 한다. 폐 MgO-C계 내화재는 현재 대부분 재활용되지 못하고 폐기되고 있는 실정이지만 다량의 MgO와 흑연 성분을 함유하고 있어 제강용 Flux로서의 효용가치가 입증되면 대량 재활용이 가능할 것으로 기대된다. 본 실험에서는 상용 EAF slag 조성을 토대로 Target 조성 범위를 설정하였다. Target EAF slag가 원만히 형성될 수 있도록 하기 위해 Flux와 함께 투입될 Pre-melt base slag를 제조하였다. Pre-melt base slag는 SiO2, Al2O3, FeO를 혼합하여 알루미나 도가니에 장입 후 1450℃에서 1시간 이상 가열하여 제조하였다. 이후 제조된 Pre-melt base slag에 혼합 Flux #2(경소돌로마이트+폐 MgO-C계 내화재+석회석)을 가하여 용융반응 시험을 수행하고 그 결과를 기존 제강 Flux에 해당하는 혼합 Flux #1(경소돌로마이트+석회석) 경우와 비교 평가하여 그 대체 가능성을 평가하였다. 신뢰성있는 평가를 도출하기 위해 XRD, XRF 및 Slag foam height, Slag basicity, 철 회수 등의 평가를 종합하였다.

가철성 다이 시스템으로 제작된 작업 모형과 솔리드 작업 모형 상에서 제작된 지르코니아 3본 고정성 치과 보철물의 변연 및 내면 적합도 비교 (Comparison of marginal and internal fit of 3-unit monolithic zirconia fixed partial dentures fabricated from solid working casts and working casts from a removable die system)

  • 이완선
    • 구강회복응용과학지
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    • 제40권2호
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    • pp.72-81
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    • 2024
  • 목적: 본 연구의 목적은 가철성 다이 시스템으로 제작된 작업 모형과 솔리드 작업 모형을 이용해 치과용 캐드캠 시스템(CAD/CAM)으로 제작된 지르코니아 3본 고정성 치과 보철물의 변연 및 내부 적합성을 평가하고자 하였다. 연구 재료 및 방법: 하악 우측 제1소구치와 하악 우측 제1대구치에 지르코니아 크라운을 위한 치아 삭제 프로토콜을 수행하고, 하악 우측 제2소구치가 없는 레퍼런스 모델을 만들었다. 레퍼런스 모델은 폴리비닐 실록산 인상체를 사용하여 복제되었고, 일반적인 치과 기공 절차에 따라 20개의 작업 모형이 제작되었다. 비교 분석을 위해, 10개의 지르코니아 3본 고정성 치과 보철물은 가철성 다이 시스템에서, 나머지 10개는 솔리드 작업 모형에서 제작되었다. 모든 작업 모형은 치과용 데스크탑 스캐너를 사용하여 디지털화되었고, 캐드 소프트웨어에서 보철물을 설계하였다. 최종 3본 고정성 치과 보철물은 밀링 과정을 통해 제작되었다. 변연 및 내부 적합도 평가는 레퍼런스 모델에 제작된 보철물을 위치시키고, 디지털 평가 방법으로 적합도가 측정되었다. 두 그룹 간의 통계 비교를 위해 Mann-Whitney U 검정이 적용되었다(α = 0.05). 결과: 가철성 다이 그룹은 솔리드 작업 모형 그룹에 비해 소구치와 대구치에서 유의하게 높은 적합도 차이를 보였으며(P < 0.05), 특히 변연 및 교합 간격에서 유의하게 높은 편차를 보였다. 색상 편차 맵에서도 가철성 다이 그룹이 변연 및 교합 영역에서 더욱 높은 편차를 보였다. 결론: 3본 고정성 치과 보철물의 적합도 차이는 가철성 다이 시스템의 작업 모형 상에서 제작된 치과 보철물에서 초래되었으며, 이를 통해 가철성 다이 제작 방법이 치과 고정성 보철물의 정확성에 영향이 있었음을 검증하였다.

해양단원 개념도 활용 수업이 과학성취도 및 태도에 미치는 효과 (The Effect of the Use of Concept Mapping on Science Achievement and the Scientific Attitude in Ocean Units of Earth Science)

  • 한정화;김광휘;박수경
    • 한국지구과학회지
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    • 제23권6호
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    • pp.461-473
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    • 2002
  • 본 연구는 지구과학 ‘해양’ 단원에서 제시된 5가지 주제에 대하여 개념도를 작성한 후 이를 중학교 과학 수업에 적용하여 그 효과를 분석하는 것을 목적으로 한다. 본 연구에서 작성된 개념도를 활용한 수업을 실험집단인 고등학교 2학년 2개 학급을 대상으로 운영하고 전통적인 수업을 실시한 비교집단과 비교한 결과는 다음과 같다. 첫째, 개념도활용 수업과 전통적인 수업이 과학성취도에 미치는 효과를 검증한 결과, 개념도 활용 수업이 전통적인 과학수업에 비해 학생들의 과학성취도에 긍정적인 효과를 미치는 것으로 나타났다. 또한 학습능력 수준에 따라 두 가지 수업의 효과를 비교한 결과, 학습능력이 높은 학습자보다 학습능력이 중 ${\cdot}$ 하위 수준의 학생들에게 더 효과적인 것으로 밝혀졌으며 개념도에서 위계가 분명한 학습내용일수록 개념도 활용 수업이 더 효과적이었다. 둘째, 개념도 활용 수업과 전통적인 수업이 과학에 대한 태도에 미치는 효과를 검증한 결과, ‘과학적 탐구에 대한 태도’ 범주와 ‘과학적 태도의 적용’ 범주에서는 개념도 활용 수업이 전통적인 수업보다 더 효과적이었다. 반면에 ‘과학수업의 즐거움’ 범주에서는 개념도 활용 수업과 전통적 수업의 효과에 차이가 나타나지 않아 개념도 작성에 대한 학습자들의 심리적인 부담을 반영해주었다. 셋째, 개념도 활용 수업 집단에 대한 설문 조사 결과 개념도 수업에 대한 학습자들의 인식은 전체적으로 긍정적인 것으로 나타났다. 하위 영역 별로 살펴보면 개념도 활용 수업이 학습내용의 이해 증진면에서 유리한 것으로 평가하였으며 학생이 작성한 개념도를 통해 수업 내용에 대한 확인이 용이하기 때문 평가도구로 활용가치가 높은 것으로 인식하였다. 파지력면에서 개념도는 배운 내용을 확인하고, 기억하는데 유용한 것으로 인식하였으나 활동성면과 흥미면에서는 다른 영역점수 보다 낮게 나타났다.가 1.2 mM, 1.8 mM인 경우 배양 14일에 염기성 인산분해효소의 활성도가 유의하게 증가하였으나, 2.5 mM인 경우 활성도가 감소하였다. 4. II-1 ${\beta}$의 활성도는 카페인을 단독 처리한 경우 0.2 mM, 1.0 mM에서, 칼슘 단독 처리시에는 1.8 mM에서, 혼합 처리시 0.1 mM 카페인과 1.8 mM 칼슘 혼합 처리한 경우 높게 나타났고, 고농도의 카페인, 칼슘 혼합 처리 시에는 낮게 나타났다 이러한 실험 결과를 통하여 칼슘이 1.2 mM, 1.8 mM 농도로 존재하는 경우 카페인에 의한 골모세포의 염기성 인산분해효소 활성과 IL-1 ${\beta}$의 활성 억제 효과가 어느 정도 회복되나, 2.5 mM 고농도의 칼슘은 억제된 활성을 회복시키지 못함을 확인하였다.지 않고 다양한 분야 즉 디자인, 생활 속에서의 벽지문양과 포장지, 예술작품 등에 활용되고 있음을 체험함으로써 수학이 실생활에 광범위하게 활용되고 있음을 알게 하였다. 역으로 생활 속에서의 테셀레이션을 통해 수학적 개념을 찾는 과정을 통해 수학이 아름다우면서도 실용적이라는 생각을 심어줄 수 있었다. 셋째, 테셀매니아, GSP, 캐브리, 거북기하 등 평소 수업에서는 활용도가 적은 컴퓨터 소프트웨어를 활용함으로써 컴퓨터 소프트웨어 자체에서 오는 호기심뿐만이 아니라 직접 조작하여 테셀레이션 작품과 개념을 익히고 새로운 작품과 학습을 해 내는 과정을 통해 자신감과 성취감 등에 있어 큰 변화가 있음을 발견할 수 있었다. 컴퓨터 기능이 미숙한 학생의 경우 처음에는 당황해 하고 어려워하는 부분도 있었으나 조작할 시간적 여유를 주고 교사와 우수한 학생들이 도우미로서 역할을 잘해내어 나중에는 큰 어려움 없이 마칠 수 있었다. 테셀레이션이라는 용어가 아직은 생소한 현장에서 교수 학습 자료가 부족하고 그에 따른 이해도 부족한

가족계획과 모자보건 통합을 위한 조산원의 투입효과 분석 -서산지역의 개입연구 평가보고- (An Intervention Study on Integration of Family Planning and Maternal/Infant Care Services in Rural Korea)

  • 방숙;한성현;이정자;안문영;이인숙;김은실;김종호
    • Journal of Preventive Medicine and Public Health
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    • 제20권1호
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    • pp.165-203
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    • 1987
  • This project was a service-cum-research effort with a quasi-experimental study design to examine the health benefits of an integrated Family Planning (FP)/Maternal & Child health (MCH) Service approach that provides crucial factors missing in the present on-going programs. The specific objectives were: 1) To test the effectiveness of trained nurse/midwives (MW) assigned as change agents in the Health Sub-Center (HSC) to bring about the changes in the eight FP/MCH indicators, namely; (i)FP/MCH contacts between field workers and their clients (ii) the use of effective FP methods, (iii) the inter-birth interval and/or open interval, (iv) prenatal care by medically qualified personnel, (v) medically supervised deliveries, (vi) the rate of induced abortion, (vii) maternal and infant morbidity, and (viii) preinatal & infant mortality. 2) To measure the integrative linkage (contacts) between MW & HSC workers and between HSC and clients. 3) To examine the organizational or administrative factors influencing integrative linkage between health workers. Study design; The above objectives called for quasi-experimental design setting up a study and control area with and without a midwife. An active intervention program (FP/MCH minimum 'package' program) was conducted for a 2 year period from June 1982-July 1984 in Seosan County and 'before and after' surveys were conducted to measure the change. Service input; This study was undertaken by the Soonchunhyang University in collaboration with WHO. After a baseline survery in 1981, trained nurses/midwives were introduced into two health sub-centers in a rural setting (Seosan county) for a 2 year period from 1982 to 1984. A major service input was the establishment of midwifery services in the existing health delivery system with emphasis on nurse/midwife's role as the link between health workers (nurse aids) and village health workers, and the referral of risk patients to the private physician (OBGY specialist). An evaluation survey was made in August 1984 to assess the effectiveness of this alternative integrated approach in the study areas in comparison with the control area which had normal government services. Method of evaluation; a. In this study, the primary objective was first to examine to what extent the FP/MCH package program brought about changes in the pre-determined eight indicators (outcome and impact measures) and the following relationship was first analyzed; b. Nevertheless, this project did not automatically accept the assumption that if two or more activities were integrated, the results would automatically be better than a non-integrated or categorical program. There is a need to assess the 'integration process' itself within the package program. The process of integration was measured in terms of interactive linkages, or the quantity & quality of contacts between workers & clients and among workers. Intergrative linkages were hypothesized to be influenced by organizational factors at the HSC clinic level including HSC goals, sltrurture, authority, leadership style, resources, and personal characteristics of HSC staff. The extent or degree of integration, as measured by the intensity of integrative linkages, was in turn presumed to influence programme performance. Thus as indicated diagrammatically below, organizational factors constituted the independent variables, integration as the intervening variable and programme performance with respect to family planning and health services as the dependent variable: Concerning organizational factors, however, due to the limited number of HSCs (2 in the study area and 3 in the control area), they were studied by participatory observation of an anthropologist who was independent of the project. In this observation, we examined whether the assumed integration process actually occurred or not. If not, what were the constraints in producing an effective integration process. Summary of Findings; A) Program effects and impact 1. Effects on FP use: During this 2 year action period, FP acceptance increased from 58% in 1981 to 78% in 1984 in both the study and control areas. This increase in both areas was mainly due to the new family planning campaign driven by the Government for the same study period. Therefore, there was no increment of FP acceptance rate due to additional input of MW to the on-going FP program. But in the study area, quality aspects of FP were somewhat improved, having a better continuation rate of IUDs & pills and more use of effective Contraceptive methods in comparison with the control area. 2. Effects of use of MCH services: Between the study and control areas, however, there was a significant difference in maternal and child health care. For example, the coverage of prenatal care was increased from 53% for 1981 birth cohort to 75% for 1984 birth cohort in the study area. In the control area, the same increased from 41% (1981) to 65% (1984). It is noteworthy that almost two thirds of the recent birth cohort received prenatal care even in the control area, indicating that there is a growing demand of MCH care as the size of family norm becomes smaller 3. There has been a substantive increase in delivery care by medical professions in the study area, with an annual increase rate of 10% due to midwives input in the study areas. The project had about two times greater effect on postnatal care (68% vs. 33%) at delivery care(45.2% vs. 26.1%). 4. The study area had better reproductive efficiency (wanted pregancies with FP practice & healthy live births survived by one year old) than the control area, especially among women under 30 (14.1% vs. 9.6%). The proportion of women who preferred the 1st trimester for their first prenatal care rose significantly in the study area as compared to the control area (24% vs 13%). B) Effects on Interactive Linkage 1. This project made a contribution in making several useful steps in the direction of service integration, namely; i) The health workers have become familiar with procedures on how to work together with each other (especially with a midwife) in carrying out their work in FP/MCH and, ii) The health workers have gotten a feeling of the usefulness of family health records (statistical integration) in identifying targets in their own work and their usefulness in caring for family health. 2. On the other hand, because of a lack of required organizational factors, complete linkage was not obtained as the project intended. i) In regards to the government health worker's activities in terms of home visiting there was not much difference between the study & control areas though the MW did more home visiting than Government health workers. ii) In assessing the service performance of MW & health workers, the midwives balanced their workload between 40% FP, 40% MCH & 20% other activities (mainly immunization). However, $85{\sim}90%$ of the services provided by the health workers were other than FP/MCH, mainly for immunizations such as the encephalitis campaign. In the control area, a similar pattern was observed. Over 75% of their service was other than FP/MCH. Therefore, the pattern shows the health workers are a long way from becoming multipurpose workers even though the government is pushing in this direction. 3. Villagers were much more likely to visit the health sub-center clinic in the study area than in the control area (58% vs.31%) and for more combined care (45% vs.23%). C) Organization factors (admistrative integrative issues) 1. When MW (new workers with higher qualification) were introduced to HSC, it was noted that there were conflicts between the existing HSC workers (Nurse aids with less qualification than MW) and the MW for the beginning period of the project. The cause of the conflict was studied by an anthropologist and it was pointed out that these functional integration problems stemmed from the structural inadequacies of the health subcenter organization as indicated below; i) There is still no general consensus about the objectives and goals of the project between the project staff and the existing health workers. ii) There is no formal linkage between the responsibility of each member's job in the health sub-center. iii) There is still little chance for midwives to play a catalytic role or to establish communicative networks between workers in order to link various knowledge and skills to provide better FP/MCH services in the health sub-center. 2. Based on the above findings the project recommended to the County Chief (who has power to control the administrative staff and the technical staff in his county) the following ; i) In order to solve the conflicts between the individual roles and functions in performing health care activities, there must be goals agreed upon by both. ii) The health sub·center must function as an autonomous organization to undertake the integration health project. In order to do that, it is necessary to support administrative considerations, and to establish a communication system for supervision and to control of the health sub-centers. iii) The administrative organization, tentatively, must be organized to bind the health worker's midwive's and director's jobs by an organic relationship in order to achieve the integrative system under the leadership of health sub-center director. After submitting this observation report, there has been better understanding from frequent meetings & communication between HW/MW in FP/MCH work as the program developed. Lessons learned from the Seosan Project (on issues of FP/MCH integration in Korea); 1) A majority or about 80% of the couples are now practicing FP. As indicated by the study, there is a growing demand from clients for the health system to provide more MCH services than FP in order to maintain the achieved small size of family through FP practice. It is fortunate to see that the government is now formulating a MCH policy for the year 2,000 and revising MCH laws and regulations to emphasize more MCH care for achieving a small size family through family planning practice. 2) Goal consensus in FP/MCH shouBd be made among the health workers It administrators, especially to emphasize the need of care of 'wanted' child. But there is a long way to go to realize the 'real' integration of FP into MCH in Korea, unless there is a structural integration FP/MCH because a categorical FP is still first priority to reduce the rate of population growth for economic reasons but not yet for health/welfare reasons in practice. 3) There should be more financial allocation: (i) a midwife should be made available to help to promote the MCH program and coordinate services, (in) there should be a health sub·center director who can provide leadership training for managing the integrated program. There is a need for 'organizational support', if the decision of integration is made to obtain benefit from both FP & MCH. In other words, costs should be paid equally to both FP/MCH. The integration slogan itself, without the commitment of paying such costs, is powerless to advocate it. 4) Need of management training for middle level health personnel is more acute as the Government has already constructed 90 MCH centers attached to the County Health Center but without adequate manpower, facilities, and guidelines for integrating the work of both FP and MCH. 5) The local government still considers these MCH centers only as delivery centers to take care only of those visiting maternity cases. The MCH center should be a center for the managment of all pregnancies occurring in the community and the promotion of FP with a systematic and effective linkage of resources available in the county such as i.e. Village Health Worker, Community Health Practitioner, Health Sub-center Physicians & Health workers, Doctors and Midwives in MCH center, OBGY Specialists in clinics & hospitals as practiced by the Seosan project at primary health care level.

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한정된 O-D조사자료를 이용한 주 전체의 트럭교통예측방법 개발 (DEVELOPMENT OF STATEWIDE TRUCK TRAFFIC FORECASTING METHOD BY USING LIMITED O-D SURVEY DATA)

  • 박만배
    • 대한교통학회:학술대회논문집
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    • 대한교통학회 1995년도 제27회 학술발표회
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    • pp.101-113
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    • 1995
  • The objective of this research is to test the feasibility of developing a statewide truck traffic forecasting methodology for Wisconsin by using Origin-Destination surveys, traffic counts, classification counts, and other data that are routinely collected by the Wisconsin Department of Transportation (WisDOT). Development of a feasible model will permit estimation of future truck traffic for every major link in the network. This will provide the basis for improved estimation of future pavement deterioration. Pavement damage rises exponentially as axle weight increases, and trucks are responsible for most of the traffic-induced damage to pavement. Consequently, forecasts of truck traffic are critical to pavement management systems. The pavement Management Decision Supporting System (PMDSS) prepared by WisDOT in May 1990 combines pavement inventory and performance data with a knowledge base consisting of rules for evaluation, problem identification and rehabilitation recommendation. Without a r.easonable truck traffic forecasting methodology, PMDSS is not able to project pavement performance trends in order to make assessment and recommendations in the future years. However, none of WisDOT's existing forecasting methodologies has been designed specifically for predicting truck movements on a statewide highway network. For this research, the Origin-Destination survey data avaiiable from WisDOT, including two stateline areas, one county, and five cities, are analyzed and the zone-to'||'&'||'not;zone truck trip tables are developed. The resulting Origin-Destination Trip Length Frequency (00 TLF) distributions by trip type are applied to the Gravity Model (GM) for comparison with comparable TLFs from the GM. The gravity model is calibrated to obtain friction factor curves for the three trip types, Internal-Internal (I-I), Internal-External (I-E), and External-External (E-E). ~oth "macro-scale" calibration and "micro-scale" calibration are performed. The comparison of the statewide GM TLF with the 00 TLF for the macro-scale calibration does not provide suitable results because the available 00 survey data do not represent an unbiased sample of statewide truck trips. For the "micro-scale" calibration, "partial" GM trip tables that correspond to the 00 survey trip tables are extracted from the full statewide GM trip table. These "partial" GM trip tables are then merged and a partial GM TLF is created. The GM friction factor curves are adjusted until the partial GM TLF matches the 00 TLF. Three friction factor curves, one for each trip type, resulting from the micro-scale calibration produce a reasonable GM truck trip model. A key methodological issue for GM. calibration involves the use of multiple friction factor curves versus a single friction factor curve for each trip type in order to estimate truck trips with reasonable accuracy. A single friction factor curve for each of the three trip types was found to reproduce the 00 TLFs from the calibration data base. Given the very limited trip generation data available for this research, additional refinement of the gravity model using multiple mction factor curves for each trip type was not warranted. In the traditional urban transportation planning studies, the zonal trip productions and attractions and region-wide OD TLFs are available. However, for this research, the information available for the development .of the GM model is limited to Ground Counts (GC) and a limited set ofOD TLFs. The GM is calibrated using the limited OD data, but the OD data are not adequate to obtain good estimates of truck trip productions and attractions .. Consequently, zonal productions and attractions are estimated using zonal population as a first approximation. Then, Selected Link based (SELINK) analyses are used to adjust the productions and attractions and possibly recalibrate the GM. The SELINK adjustment process involves identifying the origins and destinations of all truck trips that are assigned to a specified "selected link" as the result of a standard traffic assignment. A link adjustment factor is computed as the ratio of the actual volume for the link (ground count) to the total assigned volume. This link adjustment factor is then applied to all of the origin and destination zones of the trips using that "selected link". Selected link based analyses are conducted by using both 16 selected links and 32 selected links. The result of SELINK analysis by u~ing 32 selected links provides the least %RMSE in the screenline volume analysis. In addition, the stability of the GM truck estimating model is preserved by using 32 selected links with three SELINK adjustments, that is, the GM remains calibrated despite substantial changes in the input productions and attractions. The coverage of zones provided by 32 selected links is satisfactory. Increasing the number of repetitions beyond four is not reasonable because the stability of GM model in reproducing the OD TLF reaches its limits. The total volume of truck traffic captured by 32 selected links is 107% of total trip productions. But more importantly, ~ELINK adjustment factors for all of the zones can be computed. Evaluation of the travel demand model resulting from the SELINK adjustments is conducted by using screenline volume analysis, functional class and route specific volume analysis, area specific volume analysis, production and attraction analysis, and Vehicle Miles of Travel (VMT) analysis. Screenline volume analysis by using four screenlines with 28 check points are used for evaluation of the adequacy of the overall model. The total trucks crossing the screenlines are compared to the ground count totals. L V/GC ratios of 0.958 by using 32 selected links and 1.001 by using 16 selected links are obtained. The %RM:SE for the four screenlines is inversely proportional to the average ground count totals by screenline .. The magnitude of %RM:SE for the four screenlines resulting from the fourth and last GM run by using 32 and 16 selected links is 22% and 31 % respectively. These results are similar to the overall %RMSE achieved for the 32 and 16 selected links themselves of 19% and 33% respectively. This implies that the SELINICanalysis results are reasonable for all sections of the state.Functional class and route specific volume analysis is possible by using the available 154 classification count check points. The truck traffic crossing the Interstate highways (ISH) with 37 check points, the US highways (USH) with 50 check points, and the State highways (STH) with 67 check points is compared to the actual ground count totals. The magnitude of the overall link volume to ground count ratio by route does not provide any specific pattern of over or underestimate. However, the %R11SE for the ISH shows the least value while that for the STH shows the largest value. This pattern is consistent with the screenline analysis and the overall relationship between %RMSE and ground count volume groups. Area specific volume analysis provides another broad statewide measure of the performance of the overall model. The truck traffic in the North area with 26 check points, the West area with 36 check points, the East area with 29 check points, and the South area with 64 check points are compared to the actual ground count totals. The four areas show similar results. No specific patterns in the L V/GC ratio by area are found. In addition, the %RMSE is computed for each of the four areas. The %RMSEs for the North, West, East, and South areas are 92%, 49%, 27%, and 35% respectively, whereas, the average ground counts are 481, 1383, 1532, and 3154 respectively. As for the screenline and volume range analyses, the %RMSE is inversely related to average link volume. 'The SELINK adjustments of productions and attractions resulted in a very substantial reduction in the total in-state zonal productions and attractions. The initial in-state zonal trip generation model can now be revised with a new trip production's trip rate (total adjusted productions/total population) and a new trip attraction's trip rate. Revised zonal production and attraction adjustment factors can then be developed that only reflect the impact of the SELINK adjustments that cause mcreases or , decreases from the revised zonal estimate of productions and attractions. Analysis of the revised production adjustment factors is conducted by plotting the factors on the state map. The east area of the state including the counties of Brown, Outagamie, Shawano, Wmnebago, Fond du Lac, Marathon shows comparatively large values of the revised adjustment factors. Overall, both small and large values of the revised adjustment factors are scattered around Wisconsin. This suggests that more independent variables beyond just 226; population are needed for the development of the heavy truck trip generation model. More independent variables including zonal employment data (office employees and manufacturing employees) by industry type, zonal private trucks 226; owned and zonal income data which are not available currently should be considered. A plot of frequency distribution of the in-state zones as a function of the revised production and attraction adjustment factors shows the overall " adjustment resulting from the SELINK analysis process. Overall, the revised SELINK adjustments show that the productions for many zones are reduced by, a factor of 0.5 to 0.8 while the productions for ~ relatively few zones are increased by factors from 1.1 to 4 with most of the factors in the 3.0 range. No obvious explanation for the frequency distribution could be found. The revised SELINK adjustments overall appear to be reasonable. The heavy truck VMT analysis is conducted by comparing the 1990 heavy truck VMT that is forecasted by the GM truck forecasting model, 2.975 billions, with the WisDOT computed data. This gives an estimate that is 18.3% less than the WisDOT computation of 3.642 billions of VMT. The WisDOT estimates are based on the sampling the link volumes for USH, 8TH, and CTH. This implies potential error in sampling the average link volume. The WisDOT estimate of heavy truck VMT cannot be tabulated by the three trip types, I-I, I-E ('||'&'||'pound;-I), and E-E. In contrast, the GM forecasting model shows that the proportion ofE-E VMT out of total VMT is 21.24%. In addition, tabulation of heavy truck VMT by route functional class shows that the proportion of truck traffic traversing the freeways and expressways is 76.5%. Only 14.1% of total freeway truck traffic is I-I trips, while 80% of total collector truck traffic is I-I trips. This implies that freeways are traversed mainly by I-E and E-E truck traffic while collectors are used mainly by I-I truck traffic. Other tabulations such as average heavy truck speed by trip type, average travel distance by trip type and the VMT distribution by trip type, route functional class and travel speed are useful information for highway planners to understand the characteristics of statewide heavy truck trip patternS. Heavy truck volumes for the target year 2010 are forecasted by using the GM truck forecasting model. Four scenarios are used. Fo~ better forecasting, ground count- based segment adjustment factors are developed and applied. ISH 90 '||'&'||' 94 and USH 41 are used as example routes. The forecasting results by using the ground count-based segment adjustment factors are satisfactory for long range planning purposes, but additional ground counts would be useful for USH 41. Sensitivity analysis provides estimates of the impacts of the alternative growth rates including information about changes in the trip types using key routes. The network'||'&'||'not;based GMcan easily model scenarios with different rates of growth in rural versus . . urban areas, small versus large cities, and in-state zones versus external stations. cities, and in-state zones versus external stations.

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기업사회책임활동적인지인지동기류형대고객충성도적영향(企业社会责任活动的认知认知动机类型对顾客忠诚度的影响) (The Effects of the Perceived Motivation Type toward Corporate Social Responsibility Activities on Customer Loyalty)

  • Kim, Kyung-Jin;Park, Jong-Chul
    • 마케팅과학연구
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    • 제19권3호
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    • pp.5-16
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    • 2009
  • 企业社会责任活动已被认为是提高企业形象和企业竞争力的一个潜在因素. 然而, 先前大部分关于企业社会责任活动的研究是主要针对的是这些活动如何影响影响对产品, 企业以及企业形象的评价的评价. 另外, 一些学者将消费者对企业动机的感知作为企业社会责任和消费者反应之间直接关系中的调解变量. 然而, 动机理论和相关的研究存在一些缺点. 对消费者, 企业社会责任活动只有两个动机, 但最近, Vlachos等人(2008) 认为这些动机应该细分. 因此, 它有可能从原有理论发展为修正理论模型(说服, 个人知识管理(PKM). Vlachos等人(2008) 将企业社会责任动机细分为四种类型, 并尝试发现这些动机在影响顾客种程度方面的作用以及不同. 以前的研究已经证明具有积极动机会对的社会责任活动会有积极的影响. 但并没有实证地解释其心理原因. 因此本研究的目的是双重的. 第一, 本研究试图发现顾客为什么会在他们感受到企业社会活动的积极动机的情况下表达他们的感激. 第二, 本研究试图测试当社会从企业社会责任活动中获得利益时与消费者的回报的效果. 以下是本研究的假设: H1: 企业社会责任活动的价值驱使的动机积极影响认知的对等对于互惠的期待. H2: 企业社会责任活动的参股者驱使的动机消极影响于互惠的期待认知的对等. H3: 企业社会责任活动的利己驱使的动机消极影响于互惠的期待认知的对等. H4: 企业社会责任活动的战略驱使的动机消极影响对于互惠的期待认知的对等. H5: 对企业社会责任活动的互惠的期待认知的对等积极影响消费者忠诚度. 我们选择了一个公司作为研究对象来理解企业社会责任活动的动机是如何影响消费者于互惠的期待认知的对等和顾客忠诚度. 总样本为100名受访者被选为试验测试. 此外, 为了获得一致的回复, 我们保证所有的受访者都超过20岁. 本调查中. 在排除了28份无效问卷以后, 总受访者是172名(82名男性, 90名女性). 基于截至标准, 数据和模型的适配度良好. 在观察结果以后, 企业社会责任活动的价值驱使的动机对于互惠的期待认知的对等有积极的影响(t=6.75, p<.001),假设1被证明. Morales (2005) 也指出消费者的确感激企业对社会所做出的努力以及对社会所给予的利益. 而且企业社会责任活动的参股者驱使的动机对于互惠的期待认知的对等没有影响(t = ‐.049, p > .05). 因此, 假设2被拒绝. 我们可以用符合论来解释这个结果. 利己驱使动机(t = ‐3.11, p < .05)和战略驱使的动机(t = ‐4.65, p < .05) 对认知的对等有消极影响. 因此H3和H4被证明. 而且认知的对等积极影响消费者的忠诚度(t = 4.24, p < .05),H5被证明. 从结果中看, 与大众群体相比,大学生更容易受利己驱动动机的影响. 以下是本研究的结论:首先, 数据分析结果显示价值驱使的动机积极影响于互惠的期待认知的对等. 但是参股者驱动的动机对互惠的期待认知的对等没有显著影响. 另外, 利己驱使的动机和战略驱使的动机消极影响互惠的期待认知的对等. 第二, 当企业社会责任活动与消费者的回报关联时, 社会责任活动积极影响顾客忠诚度. 本研究测试了动机的种类是否影响消费者对企业社会责任的反应, 尤其是企业社会责任如何能影响关键的内在因素(认知的对等) 和消费者行为的结果(顾客忠诚度). 而且, 本研究阐述了认知对等在企业社会责任动机和顾客忠诚度的关系中起到媒介的作用. 我们的研究扩展了有关消费者企业社会责任动机方面的研究, 将他们定位为消费者反应的一个直接指标. 另外一个贡献是, 我们成功地鉴定了认知的对等作为一个次级过程在归因于顾客忠诚度的企业社会责任的影响中的中介作用. 今后在研究企业社会责任的最终行为和财务影响时应该考虑源于互惠的期待认知对等的影响. 本研究的结果具有重要的管理意义. 第一, 本研究发现的对等的中心作用表明经理人应该经常考虑这些行为将创造出多少的互惠的期待认知对等. 第二, 理解消费者对企业社会责任的动机, 的认知是如何与互惠的期待认知对等和顾客忠诚度相关, 可以帮助经理人通过营销活动和管理企业社会责任‐感应归因过程来监控和提高这些消费者的结果. 本研究的结果将帮助企业去理解影响互惠的期待认知对等的四个不同的动机的相对重要性.

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B2C허의사구중적전자구비(B2C虚拟社区中的电子口碑): 관우휴정려유망적실증연구(关于携程旅游网的实证研究) (Electronic Word-of-Mouth in B2C Virtual Communities: An Empirical Study from CTrip.com)

  • Li, Guoxin;Elliot, Statia;Choi, Chris
    • 마케팅과학연구
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    • 제20권3호
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    • pp.262-268
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    • 2010
  • 虚拟社区(virtual community, VC)今年来发展迅速, 越来越多的人参与到虚拟社区中交换信息和分享观点. 虚拟社区是通过计算机布告板和网络进行非面对面的知识和语言交流的一种大众集合体. B2C电子商务网站虚拟社区则是商业性的虚拟社区, 通过培养信任环境来促进消费者在该网站的购买行为. B2CVC通过信息交流, 如推荐, 评论, 买者与卖者评级等, 来建立社会性的氛围. 目前, 虽然学术界已经认识到B2CVC的重要性, 但是关于社区成员的口碑传播行为的研究还不充分. 本研究提出了一个理论模型, 探讨在B2C网站社区中参与度, 满意度, 信任度, 粘度和口碑传播之间的关系. 本研究的目的有三个: 1, 通过整合信念, 态度和行为的测量来实证检验B2C网站社区模型; 2, 更好地理解各因素对口碑传播的影响关系; 3, 更好地理解B2C网站社区黏度在CRM营销中的作用. 研究模型包含以下要素: 1, 社区成员的信念变量, 通过参与度来测量; 2, 社区成员的态度变量, 通过满意度和信任度来测量; 以及3, 社区成员的行为变量, 通过网站黏度和口播传播意愿来测量. 参与度是消费者在虚拟社区的参与动机. 对于社区成员来说, 信息的查找和发布是他们参与到社区的主要目的. 满意度是成员对社区整体评价的重要指标, 反映了成员与社区的交互程度. 虚拟社区的形成与发展依靠成员分享信息和服务的自愿程度. 研究者已经发现信任是促进匿名交互的关键, 因此构建信任被看作是虚拟社区的重要研究课题. 此外, 虚拟社区的成功依靠成员的粘度来提高购买潜力. 社区成员间的观点交流和信息交换代表一种 "写作式" 的口碑传播. 因此口碑传播是推动B2C虚拟社区在互联网上扩散的主要因素之一. 研究模型及假设如图一所示. 本研究通过实证调查中国携程旅游网虚拟社区成员来验证模型. 数据收集过程中共发放243份问卷, 其中有效问卷204份. 通过实证数据验证了参与度, 满意度和信任度影响粘度和口碑传播之间的假设关系. 结构方程模型(SEM)方法用来进行数据分析. 模型的拟合指数结果为χ2/df 是2.76, NFI是 .904, IFI是 .931, CFI是 .930, 以及RMSEA是 .017. 结果表明, 参与度对满意度具有显著的影响(p<0.001, ${\beta}$=0.809). 参与度可以解释满意度的方差比例超过50%, 调整R2为0.654. 参与度对信任度具有显著影响(p<0.001, ${\beta}$=0.751), 解释率为57%, 调整R2为0.563. 此外, 满意度对黏度的影响显著(${\beta}$=0.514), 但是信任度对黏度的影响并不显著(p=0.231, t=1.197). 黏度对口碑传播的影响显著, 且解释率超过80%, 调整R2为 0.846. 总之, 研究结果支持了大部分的研究假设, 但是信任度显著影响粘度的假设没有得到支持. 本研究丰富了电子商务网站虚拟社区的学术研究成果, 深入探讨了在B2C电子商务环境下的用户信念, 态度和行为等因素. 研究成果有助于实践者进行更有针对性的资源开发和市场开拓. 网络营销人员可以针对B2C网站社区来有针对性地制定营销策略, 如对于国际旅游业务, 营销人员可以针对中国的B2C网站社区用户开展营销活动, 如为活跃的用户提供特殊折扣以及为早期参与者提高社区黏度定制营销计划等. 未来的研究应该拓展社区成员行为的研究, 并在不同的行业, 社区和文化背景下开展研究.

한국 제천 감초(Glycyrrhiza uralensis Fisher)의 추출 조건별 추출물의 항산화 및 항균 활성 평가 (Antioxidant and Antibacterial Activities of Glycyrrhiza uralensis Fisher (Jecheon, Korea) Extracts Obtained by various Extract Conditions)

  • 하지훈;정윤주;성준섭;김경미;김아영;부민민;서지영;이난희;박진오;박수남
    • 대한화장품학회지
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    • 제41권4호
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    • pp.361-373
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    • 2015
  • 본 연구는 한국 제천에서 재배된 감초(Glycyrrhiza uralensis Fisher, G. uralensis)를 대상으로 추출 조건(85% 에탄올, 추출 온도 및 시간)별로 추출한 추출물에 대하여 항산화 활성 및 항균 활성을 측정하고 이로부터 최적의 추출 조건을 선정하여 감초 추출물을 화장품 원료로 개발하기 위한 제조 공정에 활용하고자 하였다. 실험에 사용한 시료는, 각 추출 조건에서 얻어진 추출물을 농축하여 분말로 한 시료(시료-1)와 추출물을 농축하지 않고 추출물 원액을 그대로 사용한 시료(시료-2)이다. 항산화 활성은 라디칼 소거활성, 총항산화능, 활성 산소로 유도된 세포손상에서 세포보호효과를 측정하였다. 항균 활성은 피부 상재균에 대한 최소저해농도를 측정하였다. 1,1,-Diphenyl-2-picrylhydrazyl를 이용한 라디칼 소거활성에서, 시료-1은 $100{\mu}g/mL$에서 추출시간이 6 h일 때가 12 h일 때보다 약 10% 정도 더 큰 라디칼 소거활성을 나타냈다. 반면에 시료-2의 라디칼 소거활성은 추출 시간에 따른 유의적 차이를 나타내지 않았다. 한편 동일 온도에서 12 h 추출한 추출물의 수율은 6 h 추출한 경우의 수율보다 2.6배 더 컸다. 하지만 총 플라보노이드 함량은 1.1배 정도 더 크게 나타났다. 따라서 추출 시간이 길어도 총플라보노이드 함량은 거의 증가하지 않았음을 보여준다. 추출 조건별 감초 추출물의 라디칼 소거활성, 총항산화능 및 세포보호효과가 추출물의 수율을 반영한 것이 아니라 추출물 중에 함유된 총플라보노이드 함량에 의존함을 나타내고 있다. 피부 상재균에 대한 항균 활성은 추출 조건별 동일 농도(시료-1)에서 측정했을 때, 세 균주(S. aureus, B. subtilis, P. acnes)에 대해 25 및 $40^{\circ}C$에서 추출된 감초추출물($156{\mu}g/mL$)은 methyl paraben ($2,500{\mu}g/mL$)보다 약 16배 정도로 매우 큰 항균 활성을 나타냈다. 결론적으로 항산화 활성 및 항균 활성이 큰 감초 추출물의 최적 추출 조건은 85% 에탄올로 $40^{\circ}C$에서 6 h 추출한 추출물이 최적임을 확인할 수 있었다. 본 연구 결과, 화장품에 항산화 활성 및 항균 활성이 큰 감초 추출물을 원료화하기 위해서는 추출 조건별 추출물의 수율, 활성 성분의 수율, 추출물의 농도별 활성 평가와 추출 수율이 반영된 추출물 원액 자체의 활성을 종합 평가해서 추출 조건을 선정해서 원료의 제조 공정에 반영하는 것이 중요함을 시사한다.

연속체 암반비탈면의 강도정수 산정 연구 (A Study on Estimating Shear Strength of Continuum Rock Slope)

  • 김형민;이수곤;이벽규;우재경;허익;이준기
    • 한국지반공학회논문집
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    • 제35권5호
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    • pp.5-19
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    • 2019
  • 암반으로 구성되어 있는 급경사($65^{\circ}{\sim}85^{\circ}$)비탈면이 장기간 안정한 상태로 유지되고 있는 자연현상을 고려할 때, 설계 및 초기 시공 단계에서 위와 유사한 지반 상태로 이루어진 깎기 암반비탈면에 대해 1:0.5(발파암 경사 기준)보다 급한 경사를 적용할 수 있을 것이다. 급경사로 설계 가능한 양호한 연속체 암반비탈면의 안정성을 검토하는 과정에서, 설계실무 측면에서 범용적인 암반강도정수 산정방법이 필요하게 되었다. Hoek 등(2002)이 수정 보완하여 발표한 Hoek-Brown 파괴기준과 GSI분류는 불연속구조의 영향을 충분히 고려한 암반특성화 시스템으로 평가되었으며, 응력변화에 따라 등가 Mohr-Coulomb 강도정수(등면적법)를 산출하는 방법을 제안하였다. 비탈면에서는 등가 M-C 강도정수가 최대구속응력(${{\sigma}^{\prime}}_{3max}$ 또는 수직응력)변화에 따라 민감하게 변화하므로 실무적으로 활용하기에 어려운 점이 있다. 이 연구에서는 양호한 연속체 암반비탈면에 대해 최대구속응력 범위이내에서 범용적으로 적용할 수 있는 강도정수산정방법(등각분할법)을 H-B 파괴기준을 응용하여 제안한다. 등각분할법 강도정수(A)의 타당성 및 적용성을 평가하기 위해, 연구대상 암반비탈면을 기존 실시설계 현장 인근에 있는 급경사 비탈면에서 암석종류별(화성암, 변성암, 퇴적암)로 선정하고, Hoek이 제시한 등가 M-C 강도정수(등면적법)들과 비교 분석하였다. 등면적법 및 등각분할법 등가 M-C 강도정수는 기본적인 자료인 기존 실시설계 현장의 실내 암석 삼축압축시험과 연구대상 암반비탈면의 불연속구조의 특성조사(Face Mapping)를 통해 RocLab 프로그램(H-B 파괴기준을 기본으로 전산화된 지반정수 산정 소프트웨어)을 활용하여 산정하였다. 산정된 등면적법 등가 M-C 강도정수는 상호 연동되어 점착력과 내부마찰각이 아주 크거나($45^{\circ}$ 이상) 작게 나타났다. 등각분할법 등가 M-C 강도정수는 등면적법 등가 M-C 강도정수의 중간 정도이며, 내부마찰각은 $30^{\circ}{\sim}42^{\circ}$의 범위를 보인다. 연구대상 암반비탈면의 등각분할법 강도정수(A)와 기존 실시 설계 현장에서 연구대상 암반비탈면과 유사한 암반상태(동일 등급 RMR)에 적용한 강도정수(B)와 비교 분석하고, 이 지반정수들로 적용한 비탈면 안정해석(한계평형해석과 유한요소해석) 결과를 통해 제안한 등각분할법의 적용성을 간접적으로 평가하였다. A와 B의 강도정수 차이는 10% 정도이다. 한계평형해석 결과(우기 기준), A적용 안전율(Fs)=14.08~58.22(평균 32.9), B적용 안전율(Fs)=18.39~60.04(평균 32.2)이며, 각 동일한 암석종류에 따라 상호 유사하게 나타났다. 유한요소 해석 결과, A적용 변위=0.13~0.65mm(평균 0.27mm), B적용 변위=0.14~1.07mm(평균 0.37mm)으로 매우 유사하다. H-B 파괴기준을 응용하여 등각분할법으로 산출한 지반 정수를 실무적인 전단강도로 적용할 수 있는 적용성 평가에서 유의미한 결과를 확인할 수 있었다.