• 대한교통학회지
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• 제20권4호
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• pp.95-107
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• 2002

혼잡세나 한계비용요금정책은 교통시설의 이용에 혼잡이 있거나 서비스 제공에 규모의 경제가 존재하는 경우 강력히 추천되는 정책도구이다. 그러나 본 논문에서는 그와 같은 시각은 당해 시설 서비스 시장만 고려할 때만 타당할 뿐 다른 시장과의 상호작용을 염두에 둔 일반균형적인 관점에서는 일반적으로 성립되지 않음을 보인다. 또한 각 정책에 대해 혼잡세나 한계비용요금정책이 실패로 돌아가는 예를 구체적으로 보이고 그에 대한 정책적 대안이 제시된다. 이 과정에서 이용량 제한이나 평균비용 요금정책 등이 놀랍게도 전통적 수단보다 우수한 정책으로 등장한다. 그러나, 이 결과는 특수한 상황에서만 성립하는 것으로 이와 관련된 연구과제들이 결론적으로 제시된다.

• Journal of Periodontal and Implant Science
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• 제38권3호
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• pp.413-428
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• 2008

Purpose: Given the predictability of dental implant procedure from the studies of successful osseointegration, implant dentistry is often the treatment of choice to replace missing teeth in edentulous patient instead of the fixed prosthesis or removable denture. The $Renova^{(R)}$ dental implant has a RBM(Resorbable Blast Media) surface, internal hex prosthetic connection and a tapered design. At this study gives the analysis of the implant and the short term survival rate of the implant. Material and Methods: In this study, a multilateral analysis was performed on the subjects undergoing placement with $Renova^{(R)}$ implant between August 2006 and February 2008 in Yonsei University dental hospital. 96 implants were placed in 56 patients and they were surveyed for cumulative survival rate. Among them 78 implants in 44 patients were surveyed for the rest analyses. Result: 1. The cumulative survival rate was 96.88% of 96 implants in 56 patients. 2. The mean marginal bone loss was 0.803mm and the marginal bone loss in augmentation group has higher value than the marginal bone loss in non augmentation group. 3. The health scale for the implants were 87% in success group, 9% in satisfactory survival group, 1% in compromised survival group, and 3% in failure group. 4. Two implants placed in poor bone posterior area by 2-stage failed during prosthetic procedure. Conclusion: $Renova^{(R)}$ dental implant showed high cumulative survival rate in installation on partial edentulous ridge and could be a predictable implant system.

• 한국농공학회논문집
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• 제57권5호
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• pp.29-35
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• 2015

The optimal greenhouse scales for controlled tomato should be studied because the increase of oil price and labor costs following the shortage of workforce makes greenhouse cultivation hard to gain profits. The purpose of this study is to estimate optimal production scales by greenhouse types for controlled tomato. The translog cost function is estimated based on the production cost survey data. The results can be summarized as follows: First, the average production cost of controlled tomato per kg decreases as the production scale increases. Second, according to the tomatoes farm of standard farming income data of RDA, the minimum production scale is 23 ton. Third, the estimated output of single-span greenhouse considering production scale with minimum average cost is 345 ton and production cost per kg is 1,476 won. The corresponding figures of multi-span greenhouse are 415 ton and 936 won, respectively. The study results can be used as basic materials for efficient decision making of tomato farmhouses and novice farmers. Also, the study shows that multi-span greenhouse should be encouraged to be built, since it requires lower marginal cost than single greenhouse. The results of this paper will help increase the income of farmhouses and cut expenses for the coming years.

• 한국어류학회지
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• 제19권4호
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• pp.324-331
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• 2007

본 연구는 남해안 여수인근 해역의 주요 어종의 하나인 개서대의 비늘을 이용하여 개서대의 연령과 성장을 추정하였다. 분석에 사용된 개서대는 2004년 2월부터 2005년 12월까지 여수 인근해역에서 기선저인망어업에 의해 어획된 어획물 중 무작위로 표본 채집하였으며, 총 402미를 조사하였고 그 중 353미를 정밀측정 및 비늘을 적출하여 연령사정에 사용하였다. 체장의 범위는 암컷이 전장 20.2~39.3 cm였으며, 수컷의 전장은 20.8~35.0 cm로 나타났다. 개서대의 체중(BW)과 체장(TL)의 관계는 $BW=0.0013TL^{3.399}$ ($R^2=0.916$)이었고, 암 수별로 체장에 대한 체중의 차이가 있었다(P<0.05). 개서대의 연령에 대한 체장자료의 오 차구조를 확인한 결과 합의 오차구조를 가지고 있었으며, 개서대의 성장식은 von Bertalanffy 성장모델을 사용하여 추정하였다. 추정된 개서대의 성장식 $L_t=43.77(1-e^{-0.186(t+2.295)})$ ($R^2=0.976$)이었다. 암 수간의 연령에 대한 체장의 상대성장에는 차이가 없었다(P>0.05).

• 천문학회보
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• 제40권1호
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• pp.77.3-78
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• 2015

It is known that the galaxy evolution by direct interaction between galaxies is most active in a galaxy group. As a result, the satellite galaxies are closely related to their central galaxy in properties such as morphology, color and star formation rate (so-called 'galactic conformity'). However, it is not clear yet whether such conformity between galaxies is found in a galaxy cluster. Recently, Lee et al. (2014) have found a measurable correlation between the colors of bright galaxies and the mean colors of their faint companions in a cluster WHL J085910.0+294957 at z = 0.3, using the photometrically-selected cluster members. They suggest that such correlation may be the vestige of infallen groups in the cluster as one possibility. In order to confirm the small-scale conformity in galaxy clusters with higher reliability, we study the Virgo cluster using the Extended Virgo Cluster Catalog (EVCC). The cluster members are selected spectroscopically unlike in WHL J085910.0+294957. We examine the galactic conformity in two distinct areas of the Virgo cluster: the inner X-ray emission region and its outer region. We find a marginal conformity in color (> $2{\sigma}$ significance to bootstrap uncertainty) in the outer region, while no meaningful signal of small-scale conformity is detected in the X-ray emission region. We discuss the implication of this result, focusing on cluster mass assembly and cluster environmental effects on galaxy evolution.

• The Journal of Asian Finance, Economics and Business
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• 제7권12호
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• pp.853-861
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• 2020

The study aims to measure the productivity of the Saudi banking sector at the retail level using secondary data for 11 local banks from the period 2015-2019. The study uses an extended version of the Cobb-Douglas production function to account for the fact that as banks openup more retail branches, they will need to employ more labor. The extended Cobb-Douglas production function was estimated using the two-way fixed effect model to account for unobserved heterogeneity across Saudi banks resulting from differences in labor competencies and leadership style. Besides, the model accounts for unobserved heterogeneity among Saudi banks due to the advancement in electronic services over time. The results showed that labor, branches, customers' deposits, and fixed deposits have a positive effect on the total value of generated loans. Conversely, ATM has an insignificant effect on generated loans. The average scale elasticity shows that the Saudi banks at the retail level are operating under decreasing returns to scale. The average marginal rate of technical substitution shows that Saudi banks need at least one ATM to replace one unit of labor at the retail level while keeping the same level of output.

• 수산경영론집
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• 제23권2호
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• pp.91-99
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• 1992

It has been one of the critical issues that the researchers properly evaluate the fishing rights foregone by the coastal development activities like wetland reclamation. Particularly, estimating the productivity of concerned fishing rights is known to play a significant role in their monetary compensation. As a result, this paper attempts to develop a statistical model characterized by Cobb-Douglas production function in conjunction with the fisheries' productivity estimation. The primary hypotheses involving their statistical production function are as below : 1. The quantity of fisheries production is hypothesized to be expressed as a function of capital (K) and labor(L) put into fishing activities. 2. The estimated parameters of K and L are hypothesized to satisfy the conventional condition of production function as a form of Cobb-Douglas. These statistical tests reveal that the shellfish farming productivity heavily depends on the acre of mariculture while the input of labor force also considerably affects its productivity. In case of the fixed net fishing productivity, both the factors of capital and labor similarly affect the marginal change in its productivity. En addition, the productivity of shellfish (arming turns out to follow the increasing returns to scale, whereas that of fixed net fishing comes up with the decreasing returns to scale.

• Journal of Preventive Medicine and Public Health
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• 제41권3호
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• pp.200-207
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• 2008

Objectives : This study examined whether serious psychological distress (SPD) is associated with occupational injury among US employees. Methods : The employed population aged 18-64 years was examined (n=101,855) using data from the National Health Interview Survey (NHIS) 2000-2003. SPD was measured using the Kessler 6-item Psychological Distress Scale (K-6), a screening scale designed to identify persons with serious mental illness. The predicted marginal prevalence of psychological distress and occupational injury with the adjusted odds ratio were estimated using multiple logistic regression analyses. Results : The age-adjusted 3-month prevalence of occupational injury was $0.80{\pm}0.12%$ in workers with SPD, which was 37% greater than in workers without SPD ($0.58{\pm}0.03%$). The odds of occupational injury in workers with SPD were higher compared to workers without SPD (OR=1.34, 95% CI=0.93-1.92), after controlling for sex, age, race, education, occupation, and activity limitation by at least one medical condition. Male, service and blue collar occupation, and activity limiation by co-morbidity showed significantly higher odds of occupational injury for workers with SPD. Conclusions : The findings suggest that SPD accounts for an increased likelihood of occupational injury among US employees. A further longitudinal study is needed to differentiate the mechanism or causal pathways linking individual injury risk at the workplace, SPD, and socioeconomic factors.

• 한국지구과학회지
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• 제33권6호
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• pp.554-566
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• 2012

성공적인 국제 Argo 사업을 통해 얻어진 고해상도의 수온 및 염분 프로파일들을 이용하여 준실시간으로 3차원 전지구 해양 상태의 재현이 가능해졌으며, 전지구 해양 자료 분석 연구에 대한 관심 또한 크게 증가하였다. 본 연구에서는 XBT와 Argo 자료의 계통 오차, 열염분 해수면 높이 및 인공위성 관측 자료와의 해수면 수지 불일치, 해양 열용량 변동 및 객관 분석장 개발 현황 등 최근의 자료 분석 연구의 주요 쟁점들에 관해 정리하였다. 특히 동아시아 해역에서의 지역 규모 해양 기후 변화 분석에 앞서 매우 신중한 해양 자료의 품질 관리 및 전구 규모의 해양 변동에 관한 이해가 필요하다는 것을 강조하였다.

• 전력전자학회논문지
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• 제4권2호
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• pp.215-222
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• 1999

전기에너지의 저장은 발전효율면이나 전력의 품질향상 등 전력시스템에서 뚜렷한 장점을 가지고 있다. 초전도 에너지 저장장치는 전기에너지를 저장할 수 있는 설비의 하나로 높은 효율과 속응성, 긴 수명 등의 특성으로 전력시스템 적용시 곧 이루어지리라 예상된다. 본 논문에서는 SMES의 국내도입시 필요한 투자정보를 제공하기 위한 최적규모 산정의 알고리즘을 제안한다. 제안한 알고리즘은 SMES의 경제적 운전 양상을 결정하는 확률적 운전모형과 최대원리를 이용한 투자계획모형으로 구성되어 있다.