• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1313-1320
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• 2011

World Business Council for Sustainable Development(WBCSD) is effort to achieve sustainable development in economic growth, environmental preservation and social development. Being this way, it is essential for developing evaluation tool which quantify to fulfill sustainable development. Eco-efficiency is one of the quantitative tools to evaluate environmental impact and economic aspect. Eco-efficiency, in general term, means creating more value of product or services with less impact to environment. It indicates as environmental impact in denominator and value of product or services in numerator. Eco-efficiency shows how much economic value reveals to unit environmental impact caused by product or service as an indicator. This study aims at developing eco-efficiency indicator of railway industry considering use stage among the entire life cycle stage of KTX and Saemaul train and also, figure out eco-efficiency value through indicator. Therethrough, it is enables to evaluate created value per environmental aspects. Since rail vehicles demands a lot of energy to transport people during use stage, the environmental impact is more significant than other lkfe cycle stages. Therefore, it quantified environmental indicator as CO2 emission and economic indicator as transportation record per a year with an annual income. This study contributes to be used as a tool for quantifying indicator of comparison evaluation in respect of rail vehicle in use stage.

• 대한토목학회논문집
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• 제35권3호
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• pp.671-678
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• 2015

도로, 철도 등 대규모 교통시설 투자사업의 예비타당성 조사에서 경제성 분석 결과만을 기준으로 사업의 타당성을 평가할 경우, 사회경제지표가 열악한 지역이 투자에서 소외될 수 있어 지역낙후도 지수를 정책적으로 반영하고 있다. 하지만 기존의 지역낙후도 산정 지표는 사람과 물자의 수송에 얼마나 유리한 교통 시설을 갖추고 있는가를 나타내는 교통연계성을 반영하지 못하고 있다. 따라서 본 연구에서는 지역낙후도 결정 시 교통연계성을 반영하기 위해 등시간선도, 지역 간 이동거리 및 소요시간, 우회도 등을 적용해 보았다. 새로운 지표 활용 시 기존의 낙후도 순위가 변경되는 결과를 확인할 수 있는데, 이는 현재의 낙후도 지수에 교통연계성을 반영하는 지표를 추가하는 것이 정책적 결정에 영향을 미칠 수 있음을 의미한다고 볼 수 있다. 본 연구에서는 지역낙후도 산정 시 교통연계성을 고려해야 할 당위성을 제시하였고, 기존의 연구들과는 달리 지역 간 교통연계성을 나타내는 지표를 개발하여 기존의 지역낙후도 지수에 반영하는 절차를 수행하였다는데 연구의 의의를 둘 수 있다.

• 대한기계학회논문집A
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• 제25권9호
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• pp.1444-1451
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• 2001

The evolutionary structural optimization(ESO) method has been under continuous development since 1992. The bidirectional evolutionary structural optimization(BESO) method is made of additive and removal procedure. The BESO method is very useful to search the global optimum and to reduce the computational time. This paper presents the ranked bidirectional evolutionary structural optimization(R-BESO) method which adds elements based on a rank, and the performance indicator which can estimate a fully stressed model. The R-BESO method can obtain the optimum design using less iteration number than iteration number of the BESO.

• 한국패류학회지
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• 제30권3호
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• pp.189-196
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• 2014

A significant production decrease has been witnessed for the Pacific oysters, Crassostrea gigas farmed in the western coastal waters of Korea, presumably by the loss of physiological viability. We evaluated the viability in terms of health indicators, the condition indices and hemocyte apoptosis rates of the oysters inhabiting two representative farming sites, Incheon and Taean each with different environmental variables. In our monthly measurements for the whole year 2013, the indicators were location specific. The condition indices of Incheon were highly variable, 1.67-8.58%, while those of Taean were less, 2.28-5.57%. The condition indices decreased during the spawning seasons, July and September in common. The two oysters exhibited also differed in the apoptotic activities of hemocyte, highly active, 4.03-30.15% for Incheon oysters and less active, 2.87-17.48% for Taean oysters. One thing we could identify was the two measurements were adverse during the critical seasons of spawning, reminiscent of being a useful tool for a health indicator for the oysters. Similar trend was also observed in the time when change in temperature was extreme. The findings in this study are highly indicative of health indicators for the oyster aquaculture.

• 전기학회논문지
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• 제66권1호
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• pp.229-236
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• 2017

The railway has recently been expanded with the phase of the future transportation. Accordingly, using the new technologies such as smart devices and LTE-R, the needs for reducing operational costs and improving passenger services have emerged. To realize these needs, the government is pushing to build the dedicated wireless network for the railway systems. In this paper, the shunting route indicator was selected for this study because it has the best effect for the wireless system removed lots of wired cables. And the wireless shunting route indicator applied with LTE-R technology was developed to replace the current wired control system. The functional goal(the wireless control function applied LTE-R), the performance goal(less than 300ms for transferring the control information), and the reliability goal(over the 100,000 hours for MTBF) were set, and these goals were achieved and demonstrated through the test and validation.

• 한국항해항만학회지
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• 제41권5호
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• pp.319-328
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• 2017

The efficiency of port operations is an important indicator of port development. Moreover, there is excess handling capacity in Chinese ports, which results in a slower speed of development. Under the detrimental environment of the international shipping market, it is necessary to improve the operation efficiency of ports for long-term development. This paper provides an assessment of the competitiveness of Chinese seaport companies using the Boston Consulting Group's matrix, and efficiency measurements using a data envelopment analysis and the Malmquist method. This analysis showed that highly efficient companies reformed their development strategies, which should be a solution considered by less efficient companies, such as Shenzhen Yan Tian Port Holdings Co., Ltd.. Although, having high throughput should be reformed in the investment structure. This research will assist port companies in gaining effective operating experience, and governments in establishing strategic planning to enhance the efficiency of port development.

• Journal of Chest Surgery
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• 제53권6호
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• pp.325-331
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• 2020

Background: We evaluated the association between tricuspid annular dilatation and the development of moderate or severe tricuspid regurgitation (TR). Additionally, we determined the optimal tricuspid annular dilatation threshold to use as an indicator for tricuspid annuloplasty in patients with less-than-moderate functional TR (FTR). Methods: Between August 2007 and December 2014, 227 patients with less-than-moderate TR underwent mitral valve surgery without a tricuspid valve (TV) procedure. The TV annular diameter was measured via transthoracic echocardiography. The TV annular index (TVAI) was calculated as the TV annular diameter divided by the body surface area. The mean duration of echocardiographic follow-up was 42.0 months (interquartile range, 9.3-66.6 months). Results: Eight patients (3.5%) developed moderate or severe TR. The rate of freedom from development of moderate or severe TR at 5 years was 96.2%. TV annular diameter, left atrial diameter, preoperative atrial fibrillation, and TVAI were found to be associated with the development of moderate or severe TR in the univariate analysis. A cut-off TVAI value of 19.8 mm/㎡ was found to predict the development of moderate or severe TR, and a significant difference was observed in the development of TR of this severity based on this cut-off (p<0.001). Conclusion: The progression of TR was not infrequent in patients with untreated lessthan-moderate FTR. An aggressive treatment approach can be helpful to prevent the progression of FTR for patients with risk factors, especially TVAI greater than 19.8 mm/㎡.

• KDI Journal of Economic Policy
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• 제45권3호
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• pp.25-48
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• 2023

The current article has explored the effect of productive capacities (as defined by the United Nations Conference on Trade and Development) and of structural economic vulnerability (as defined by the United Nations) on fiscal space volatility in developing countries. It relies on the definition and measure of fiscal space proposed by Aizenman and Jinjarak (2010; 2011) and Aizenman et al. (2019). To compute the indicator of fiscal space and hence that of fiscal space volatility, fiscal space is considered as the ratio of outstanding public debt to the 'de facto tax base', the latter being the number of years of tax revenues needed for a country to repay its debt. Results based on a sample of 116 countries from 2000 to 2018 have revealed that the enhancement of productive capacities is associated with lower fiscal space volatility, while higher structural economic vulnerability heightens fiscal space volatility. On another note, highly vulnerable countries tend to experience a higher negative effect of productive capacities on fiscal space volatility than relatively less vulnerable countries.

• 조명전기설비학회논문지
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• 제27권3호
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• pp.1-6
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• 2013

In this study, we propose a fiber-optic hydrogen sensor using a polarization-diversity loop configuration composed of a polarization beam splitter, two quarter-wave plates, and a polarization-maintaining fiber coated with palladium whose thickness is ~400nm. One transmission dip of the output interference spectrum of the proposed sensor, chosen as a sensor indicator, was observed to spectrally shift with the increase of the hydrogen concentration, and the sensing indicator showed a wavelength shift of ~2.48nm at a hydrogen concentration of 4%. Except for a hydrogen concentration of 4%, the response time of the proposed sensor was measured as less than 12.5s and did not show significant dependence on the hydrogen concentration. In particular, the proposed fiber hydrogen sensor is more durable and highly resistant to external stress applied on a transverse axis of an optical fiber, compared with other hydrogen sensors based on side-polished fibers or fiber gratings.

• Journal of Forest and Environmental Science
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• 제29권3호
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• pp.219-225
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• 2013

The correlation between disturbance intensity and stand development was evaluated on the basis of natural forest community type classification in areas of Baekhaksan (more disturbed area) and Hwangaksan (less disturbed area). The vegetation data were collected by point-centered quarter sampling method, and they were subjected to cluster analysis for classifying community types and to analysis of species composition and species diversity for reviewing ecological characteristics. By the method of cluster analysis, natural forests of Baekhaksan were classified into Quercus forest community, Pinus densiflora community, Q. variabilis community, and Q. mongolica community. Those of Hwangaksan were divided into P. densiflora community, Q. mongolica community, Q. forest community, and Mixed mesophytic community. It is presumed that more developed and less disturbed forest area shows multiple species community pattern and more diversified structure than less developed and more disturbed forest area. In Korean peninsula, the abundance of red pine may play an important indicator to estimate the developmental pattern of the forest after artificial disturbance. The overall evaluation indicated that less disturbed Hwangaksan area had more developed stand pattern with mixed mesophytic community, more complicated species composition, and higher species diversity than Baekhaksan area.