• Title/Summary/Keyword: Scale-model

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What Happened to Efficiency and Competition after Bank Mergers and Consolidation in Korea? (한국 은행들의 합병, 통합 이후 효율성과 경쟁도는 개선되었는가?)

  • Park, Kang H.
    • KDI Journal of Economic Policy
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    • v.33 no.3
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    • pp.33-55
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    • 2011
  • Market concentration in the Korean banking industry has markedly increased since the financial crisis of 1997-1998 because of M&As, P&As, and consolidation of banks. With this change, there has been a growing concern over market power in the Korean banking sector. We examine the effects of market concentration on bank efficiency and competition for the period of 1992-2006. Three different indicators of bank inefficiency are used in this study, including X-inefficiency that is derived from the directional technology distance function. The level of competition is measured by both the H-statistic of the Panzar-Rosse model and the level of the net interest margin and its standard deviation. Empirical results indicate that market concentration has not improved bank efficiency through scale economies or scope economies. Instead, recent mergers, acquisitions and consolidation of banks resulted in an increase in inefficiency measured by the three different indicators: X-inefficiency, labor inefficiency and asset inefficiency. While an increase in market share of individual banks improved bank efficiency, an increase in the overall market concentration ratio resulted in lower efficiency. Our study also finds that the Korean banking sector has been monopolistically competitive throughout the sample period except for the crisis period according to the H-statistic. Although an increase in market concentration ratio has not changed the overall level of bank competition, it has a positive significant effect on the level of the average interest margin.

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Seismic Performance Preliminary Evaluation Method of Reinforced Concrete Apartments with Bearing Wall system (기존 철근콘크리트 벽식 공동주택의 내진 성능 예비 평가법에 관한 연구)

  • Chung, Lan;Woo, Sung-Sik;Choi, Ki-Young;Park, Tae-Won
    • Journal of the Korea Concrete Institute
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    • v.19 no.3
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    • pp.293-300
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    • 2007
  • In Korea, the seismic design regulations was established since 1988 about regularity scale of structures. However, It was not established about seismic performance and evaluation method as the most existing buildings was constructed before Earthquake-Resistant Design(1988). In this study, for model structures which are 4 units of non-seismic designed apartment and 3 units of seismic designed in Korea performed seismic performance evaluation by suggested KISTC (2004). And the result compare to evaluate Capacity Spectrum Method by using MIDAS Gen and SDS. As a result, we observed that suggested KISTC's method have overestimated for shear stress and drift index. The purpose of this study provides most conformity seismic performance evaluation process and the appropriate method of calculating the seismic performance index in Korea.

Early bone healing onto implant surface treated by fibronectin/oxysterol for cell adhesion/osteogenic differentiation: in vivo experimental study in dogs

  • Lee, Jung-Seok;Yang, Jin-Hyuk;Hong, Ji-Youn;Jung, Ui-Won;Yang, Hyeong-Cheol;Lee, In-Seop;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
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    • v.44 no.5
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    • pp.242-250
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    • 2014
  • Purpose: This study aimed to evaluate the effects of fibronectin and oxysterol immobilized on machined-surface dental implants for the enhancement of cell attachment and osteogenic differentiation, on peri-implant bone healing in the early healing phase using an experimental model in dogs. Methods: Five types of dental implants were installed at a healed alveolar ridge in five dogs: a machined-surface implant (MI), apatite-coated MI (AMI), fibronectin-loaded AMI (FAMI), oxysterol-loaded AMI (OAMI), and sand-blasted, large-grit, acid-etched surface implant (SLAI). A randomly selected unilateral ridge was observed for 2 weeks, and the contralateral ridge for a 4-week period. Histologic and histometric analyses were performed for the bone-to-implant contact proportion (BIC) and bone density around the dental implant surface. Results: Different bone healing patterns were observed according to the type of implant surface 2 weeks after installation; newly formed bone continuously lined the entire surfaces in specimens of the FAMI and SLAI groups, whereas bony trabecula from adjacent bone tissue appeared with minimal new bone lining onto the surface in the MI, AMI, and OAMI groups. Histometric results revealed a significant reduction in the BIC in MI, AMI, and OAMI compared to SLAI, but FAMI demonstrated a comparable BIC with SLAI. Although both the BIC and bone density increased from a 2- to 4-week healing period, bone density showed no significant difference among any of the experimental and control groups. Conclusions: A fibronectin-coated implant surface designed for cell adhesion could increase contact osteogenesis in the early bone healing phase, but an oxysterol-coated implant surface designed for osteoinductivity could not modify early bone healing around implants in normal bone physiology.

Search for Viable Alternative for the Korean Occupational Welfare System at the Crossroad (전환점에 서있는 한국기업복지제도의 한 대안으로서 근로자협조프로그램의 적용성에 관한 연구)

  • Kim, Ui-Myong
    • Korean Journal of Social Welfare
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    • v.36
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    • pp.71-99
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    • 1998
  • There is a general consensus that fate of the differentiated welfare state had fallen into the brink of demise during the 1970s while the integrated welfare state model has emerged instead. Indications are all that such trend spotlights occupational welfare which has been relatively neglected, especially, in the field of social welfare. Nevertheless, the occupational welfare system in Korea faced crisis due to two major incidents. One is the IMP crisis which necessitates massive scale of restructuring of the general fabric of the Korean business and industry. There is little doubt that the economic crisis will surely cut down occupational welfare expenditure substantially. The other is a report released by the Korean Labor Research Institute which argus that there is no correlation between the Korean occupational welfare system and labor productivity. Thorough investigation of the Korean occupational welfare system suggests that current system is so outdated that it doesn't meet needs of the industrial workforce which, in turn, fails to enhance workers productivity. Consequently, a need for new paradigm and system arises and employee assistance program(EAP) emerges as a viable alternative. EAP is thoroughly delianeated of it's definition, motivations, functions, ingredients, historical background as well as cost-effectiveness. But major tasks center around an investigation and an analysis of it's applicability. In-depth analysis was carried out on the issue of it's indispensable natures and stumbling blocks on the way to lay it's root in the Korean industrial environment. It seems harder than the herculean task. However, EAP is not simply an alternative but is rather a pressing imperative for the present occupational welfare system in Korea which stands at the crossroad.

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Development of Precast Hollow Concrete Columns with Non-Shrink Mortar Grouting Type Splice Sleeve (무수축 모르타르 충진형 슬리브를 사용한 중공 프리캐스트 교각 개발)

  • Cho, Jae-Young;Lee, Young-Ho;Kim, Do-Hak;Park, Jong-Heon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.3A
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    • pp.215-225
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    • 2011
  • In general, the precast columns can obtain its homogeneous quality as they are produced in a factory with a hollow concrete block type by using high strength concrete, so that they can generate the reduction of dead load. Such a method of precast hollow concrete columns is already implemented in USA and Japan and used for connecting between blocks which use PC tendons. However, it is inevitable to have uneconomical construction with excessive cost in early stage when PC tendons are used. This study aims to develop an economical precast column with high quality and constructability which consists of only splice sleeve and general reinforcing bar without using PC tendons in order to reduce the construction period and cost. To achieve this goal, this study tested the performance of total 5 minimized models in the experiment with the variables such as hollowness, diameter of main reinforcement bar and cross-sectional size for the cross section of precast column by using grouting type splice sleeve which is a new type joint rebar. And it also verified the performance of column in the experiment for a large-sized model in order to overview its applicability by excluding large scale effect.

Development of Measurement Standard Scale for Festival contents quality (CONTSQUAL) (지역축제 콘텐츠품질(CONTSQUAL) 척도 개발)

  • Maeng, Hae-Yeong;Jang, Hyeong-Yu
    • The Journal of the Korea Contents Association
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    • v.12 no.12
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    • pp.742-760
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    • 2012
  • Festival contents have played a role as a mediator that connects consumers and producers of the Festivals to express the purpose or theme of those. The successful quality factors to be successively sustainable excellent Festivals include ritual, experience, exhibition, sales, education, competitive, performance. In this study, Festival contents scales, that is named CONTSQUAL, being consisted of seven factors were drawn through the analysis of Cultural Tourism Festival 2012. Festival CONTSQUAL is ritual, experience, exhibition, sales, education, competitive, performance. The research sample is participants in the "Geumsan Insam Festival". Empirical analysis was carried out for visitors to verify the scales and research model. As a result, among festival CONTSQUAL, all components of qualities affected positively on Festival Flow but ritual and education. Festival flow affected positively on festival satisfaction while festival satisfaction affected positively on behavior intention. This study not only measured festival quality through the newly developed CONTSQUAL scales underlying sustainable competitive festival, but also built basic foundation for objectively assessing the festival contents quality, which would result in ensure successful local festival.

Relationship Between Status of Physical and Mental Function and Quality of Life Among the Elderly People Admitted from Long-Term Care Insurance (장기요양 인정자의 신체적 및 정신적 기능 상태와 삶의 질과의 관계)

  • Kim, Hyeong-Seon;Bae, Nam-Kyou;Kwon, In-Sun;Cho, Young-Chae
    • Journal of Preventive Medicine and Public Health
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    • v.43 no.4
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    • pp.319-329
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    • 2010
  • Objectives: This study was performed to determine the levels of quality of life (QOL) according to the grade of long-term care service for the elderly people who were admitted from long-term care insurance, and to reveal its association with the physical and mental functioning such as the Activity of Daily Living (ADL), the Instrumental Activity of Daily Living (IADL), the Center for Epidemiologic Studies Depression Scale (CES-D), and the Mini-Mental State Examination-Korean version (MMSE-K). Methods: The interviews were performed during the period from March 1 to May 31, 2009, for 958 elderly people in urban and rural areas. The questionnaire items included various indices such as the ADL, IADL, CES-D, and MMSE-K, as independent variables and the index of QOL, as the dependent ones. For statistical analysis, t-tests were used for the mean scores of QOL according to gender and the grade of long-term care services, and Spearman's correlation was used for each variable. The effects of physical and mental functioning for QOL were assessed by covariance structure analysis. The statistical significance was set at p<0.05. Results: The mean scores of QOL among all the subjects was $55.4{\pm}15.62$ (Grade I: $49.7{\pm}14.17$, Grade II: $56.8{\pm}14.62$, Grade III: $59.4{\pm}16.36$), and it was lower according to the higher grade of long-term care insurance. In terms of the correlation matrix of the QOL and the physical and mental function factors, the QOL showed positive correlation with the ADL, IADL and MMSE-K, while it had negative correlation with depression. On the analysis of covariance, mental functioning (depression and the MMSE-K) had a greater influence on the level of QOL than the physical functioning (ADL and IADL). Conclusions: The level of the QOL in the elderly people who were admitted from long-term care insurance was lower according to higher the grade of long-term care insurance. Also, the mental functioning (depression and MMSE-K) was more influential on the level of the QOL than the physical functioning (ADL and IADL).

A Study on the Effects of Absorptive Treatments for the Highway Noise Barriers (도로교통소음의 방음벽 흡음효과에 관한 연구)

  • 김재석;루이스칸;김갑수
    • Journal of KSNVE
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    • v.8 no.1
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    • pp.146-156
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    • 1998
  • To mitigate excessive noise from highways, and high speed rail road, it is often necessary to construct a noise barrier. Absorptive barroer attenuation solution is obtained for the problem of diffration of a plane wave sound source by a semi-infinite plane. A finite region in the vicinity of the edge has an highly absorbing boundary condition ; the remaining portion of the half plane is rigid. The problem which is solved is a mathematical model for a hard barrier with an absorbing edge. If the wavelength of the sound is much smaller than the length scale associated with the barrier, the diffraction process is governed to all intents and purpose by the solution to a standard problem of diffraction by a semi-infinite hard plane with an absorbent edge. It is concluded that the absorbing material that comprises the edge need only be of the order of a wavelength long to have approximately the same effect, on the sound attenuation in the shadow side of the barrier. Traffic noise is composed of thousands of sources with varying frequency content. To simplify noise predictions when barriers are present, an effective frequency of 550Hz may be used to represent all vehicles. The wavelength of sound at f=550Hz for traffic noise is about 2 feet. According to the above conclusion, an absorptive highway noise barrier is only needed to cover to cover approximately a 2 foot length of absorbing material. It would be more economical to cover only the region in the immediate vicinity of the edge with highly sound obsorbent material.

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Seismic performance evaluation of middle-slab vibration damping rubber bearings in multi-layer tunnel through full-scale shaking table (실대형 진동대 시험을 통한 복층터널 중간 슬래브 진동 감쇠 고무받침 내진성능 평가)

  • Jang, Dongin;Park, Innjoon
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.22 no.4
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    • pp.337-346
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    • 2020
  • Traffic jam and congestion in urban areas has caused the need to improve the utility of underground space. In response, research on underground structures is increasingly being conducted. Notably, a double-deck tunnel is one of the most widely used of all those underground structures. This double-deck tunnel is separated by the middle slab into the upper and lower roadways. Both vehicle load and earthquake load cause the middle slab to exhibit dynamic behavior. Earthquake-related response characteristics, in particular, are highly complex and difficult to interpret in a theoretical context, and thus experimental research is required. The aim of the present study is to assess the stability of a double-deck tunnel's middle slab of the Collapse Prevention Level and Seismic Category 1 with regard to the presence of vibration-damping Rubber Bearings. In vibration table tests, the ratio of similitude was set to 1/4. Linings and vibrating platforms were fixed during scaled model tests to represent the integrated behavior of the ground and the applied models. In doing so, it was possible to minimize relative behavior. The standard TBM cross-section for the virtual double-deck tunnel was selected as a test subject. The level of ground motion exerted on the bedrock was set to 0.154 g (artificial seismic wave, Collapse Prevention Level and Seismic Category 1). A seismic wave with the maximum acceleration of 0.154 g was applied to the vibration table input (bedrock) to analyze resultant amplification in the models. As a result, the seismic stability of the middle slab was evaluated and analyzed with respect to the presence of vibration-damping rubber bearings. It was confirmed that the presence of vibration-damping rubber bearings improved its earthquake acceleration damping performance by up to 40%.

Associations of ERCC4 rs1800067 Polymorphism with Cancer Risk: an Updated Meta-analysis

  • Yuan, Quan;Liu, Jing-Wei;Xing, Cheng-Zhong;Yuan, Yuan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.18
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    • pp.7639-7644
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    • 2014
  • Background: Results from previous studies concerning the association of ERCC4 rs1800067 polymorphism with risk of cancer were inconsistent. To explore the exact relation with susceptibility, we conducted the present meta-analysis. Materials and Methods: Literature of electronic databases including PubMed, Web of Science, EMBASE, Wanfang and Chinese National Knowledge Infrastructure (CNKI) were systematically searched. ORs and their 95%CIs were used to assess the strength of associations between ERCC4 polymorphism and cancer risk. Results: There was no significant association between ERCC4 rs1800067 AA or AG genotypes and overall risk of cancer (AA vs. GG: OR=0.998, 95%CI=0.670-1.486, P=0.992; AG vs. GG: OR=0.970, 95%CI=0.888-1.061, P=0.508). A dominant genetic model also did not demonstrate significant association of (AA+AG) genotype carriers with altered risk of overall cancer (OR=0.985, 95%CI=0.909-1.068, P=0.719). In addition, no significant association was observed between A allele of ERCC4 rs1800067 A/G polymorphism and altered cancer risk compared with G allele (OR=0.952, 95%CI=0.851-1.063, P=0.381). Subgroup analysis suggested that AA genotype carriers were significantly associated with decreased risk of glioma compared with wild-type GG genotype individuals (OR=0.523, 95%CI=0.275-0.993, P=0.048). For subgroup of lung cancer, A allele of ERCC4 rs1800067 A/G polymorphism was significantly associated with decreased risk of lung cancer compared with G allele (OR=0.806, 95%CI=0.697-0.931, P=0.003). Conclusions: This meta-analysis indicated that ERCC4 rs1800067 A/G polymorphism might not be associated with risk of overall cancer. However, individuals with the AA genotype were associated with significantly reduced risk of glioma compared with wild-type GG genotype; The A allele was associated with significantly reduced risk of lung cancer compared with G allele. Future large-scale studies performed in multiple populations are warranted to confirm our results.