• 한국ITS학회 논문지
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• 제8권5호
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• pp.85-97
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• 2009

지속적인 교통수요 증가로 인하여 만성적인 교통혼잡, 연료소비 증가, 대기오염과 교통사고 등의 심각한 문제가 야기되고 있다. 이러한 문제점을 해결하고자 2007년 국토해양부 주관으로 스마트하이웨이 사업이 시작되었다. 스마트하이웨이 사업 중 도로-자동차 연계기술 중 하부 기술인 주행로이탈예방지원시스템(Lane Departure Warning System : LDWS)은 운전자가 고속도로에서 고속 주행 중 차로를 이탈할 경우 운전자에게 경고를 제공하는 시스템으로 측면충돌과 도로이탈사고를 예방하는 기술이다. 본 사업을 수행하기에 앞서 본 기술을 도입함으로 인하여 발생되는 경제성을 분석하여 타당성을 검증할 필요성이 있다. 따라서 본 연구에서는 LDWS 구축에 따른 사회경제적 효과를 분석하기 위하여 비용-편익분석 (Cost-Benefit Analysis : CBA)을 적용하였다. 발생되는 편익으로는 사고감소효과와 운전자 측면 편익을 산정하였다. 또한 주행로이탈예방지원기술의 경우 보급률에 따라 경제성이 달라지는 것을 고려하여 비관적 시나리오와 낙관적 시나리오로 구분하여 각각의 경제성을 분석하였다. B/C비 분석 결과 비관적 시나리오의 경우 2020년 0.97, 2030년 1.36으로 경제성이 있는 것으로 나타났으며, 낙관적 시나리오에서는 2020년 1.04, 2030년 1.59로 보급률이 높아질수록 경제성 또한 높아지는 것으로 나타났다. 따라서 주행로이탈예방지원기술의 도입을 통해 발생되는 경제성이 있는 것으로 판단된다.

• 한국유기농업학회지
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• 제22권3호
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• pp.491-502
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• 2014

본 연구는 천연물질에서 유래한 반추위 메탄저감용 친환경 첨가제 개발을 위해 각기 다른 종균을 이용하여 발효한 세신 추출물의 항균활성, 항산화활성 및 in vitro 반추위 발효시험을 체계적으로 실시하였다. 접종된 균주들의 성장효율을 알아보기 위해 실시한 생균수측정 결과 L. curvatus NJ40 균주에서 유의적으로 높은 균주성장을 나타냈다(p<0.05). 항균활성측정 결과는 대조구 대비 L. curvatus NJ40 및 L. plantarum NJ45 균주와 발효된 세신 추출물이 병원균에 대한 항균효과를 나타내는 것으로 조사되었다. In vitro 반추위 발효실험에 세신 및 발효 세신 추출물을 적용한 결과, 휘발성 지방산 생성량 대비 반추위 메탄 저감효과가 나타났다. 특히 반추위 미생물 활력 및 사료이용 효율을 대표할 수 있는 휘발성 지방산 생성효율에 대한 부정적 효과 없이, 오히려 휘발성지방산 생성효율을 향상시키면서 반추위 메탄 저감효과를 가져올 수 있는 것으로 나타났다.

• 한국대기환경학회지
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• 제25권2호
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• pp.133-140
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• 2009

In order to examine the effects of micrometeorological and climatological influences on urban scale particulate air pollutants observed in Busan, power spectrum analysis was applied to the observed particulate matter with aerodynamic diameter ${\le}10{\mu}m$ ($PM_{10}$) for the period from 1991 to 2006. Power spectrum analysis has been employed to the daily mean $PM_{10}$ concentrations obtained at 13 sites to identify different scales of periodicities of $PM_{10}$ concentrations. The results show that, aside from the typical and well-known periodicities such as diurnal and annual variations caused by anthropogenic emission influences, another two significant peaks of power spectrum density were identified: 21 day and $3{\sim}4$ year of periodicities. Cospectrum analysis indicates that the intraseasonal 21 day periodicity are found to be negatively correlated with wind speed and surface pressure but shows consistently positive with relative humidity and temperature. This result implied that 21 day periodicity is presumably relevant to the secondary aerosol formation processes through the photochemical reaction that can be subsequently resulted from hygroscopic characteristics of aerosol formation. However, the interannual $3{\sim}4$ year of periodicity is found to have positive correlation with pressure, and negative with temperature and relative humidity, which is rather consistent with both characteristics of air mass during the Asian dust event and the occurrence frequency of Asian dust whose periodicities have been recorded inter-annually over the Korean peninsula.

• Asian Journal of Atmospheric Environment
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• 제5권4호
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• pp.228-236
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• 2011

Since most Green House Gases (GHGs) and air pollutants are generated from the same sources, it will be cost-effective to develop a GHGs reduction plan in combination with simultaneous removal of air pollutants. However, effects on air pollutants reduction according to implementing any GHG abatement plans have been rarely studied. Reflecting simultaneous removal of air pollutants along with the GHGs emission reduction, this study investigated relative cost effectiveness among GHGs reduction action plans in Busan Metropolitan City. We employed the Data Envelopment Analysis (DEA), a methodology that evaluates relative efficiency of decision-making units (DMUs) producing multiple outputs with multiple inputs, for the investigation. Assigning each GHGs reduction action plan to a DMU, implementation cost of each GHGs reduction action plan to an input, and reduction potential of GHGs and air pollutants by each GHGs reduction action plan to an output, we calculated efficiency scores for each GHGs reduction action plan. When the simultaneous removal of air pollutants with the GHGs reduction were considered, green house supply-insulation improvement and intelligent transportation system (ITS) projects had high efficiency scores for cost-positive action plans. For cost-negative action plans, green start network formation and running, and daily car use control program had high efficiency scores. When only the GHGs reduction was considered, project priority orders based on efficiency scores were somewhat different from those when both the removal of air pollutants and GHGs reduction were considered at the same time. The expected action plan priority difference is attributed to great difference of air pollutants reduction potential according to types of energy sources to be reduced.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.73.1-73.1
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• 2010

For the successful cold starting of a fuel cell engine, either internal of external heat supply must be made to overcome the formation of ice from water below the freezing point of water. In the present study, switchable vanadium oxide compounds as variable temperature-electrical resistance materials onto the surface of flat metallic bipolar plates have been prepared by a dip-coating technique via an aqueous sol-gel method. Subsequently, the chemical composition and micro-structure of the polycrystalline solid thin films were analyzed by X-ray diffraction, X-ray fluorescence spectroscopy, and field emission scanning electron microscopy. In addition, it was carefully measured electrical resistance hysteresis loop over a temperature range from $-20^{\circ}C$ to $80^{\circ}C$ using the four-point probe method. The experimental results revealed that the thin films was mainly composed of Karelianite $V_2O_3$ which acts as negative temperature coefficient materials. Also, it was found that thermal dissipation rate of the vanadium oxide thin films partially satisfy about 50% saving of the substantial amount of energy required for ice melting at $-20^{\circ}C$. Moreover, electrical resistances of the vanadium-based materials converge on an extremely small value similar to that of pure flat metallic bipolar plates at higher temperature, i.e. $T{\geq}40^{\circ}C$. As a consequence, experimental studies proved that it is possible to apply the variable temperature-electrical resistance material based on vanadium oxides for the cold starting enhancement of a fuel cell vehicle and minimize parasitic power loss and eliminate any necessity for external equipment for heat supply in freezing conditions.

• 대한두경부종양학회지
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• 제36권2호
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• pp.73-77
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• 2020

Ovarian cancer is common malignant disease with high mortality in the female. However, lymph node metastasis in the head and neck of ovarian cancer is very rare than in para-aortic, pelvic lymph node. A 49-year-old female patient came to our clinic with a left neck mass. After total thyroidectomy and left selective neck dissection for the cervical neck level II, III, IV, V, VI for ovarian cancer and thyroid cancer, she had already undergone chemotherapy (Paclitaxel+Carboplatin) 18 month ago. CT scan showed only lymph node enlargement in left neck level II. Positron emission tomography-computed tomography (PET-CT) revealed a hypermetabolic lesion in same area but no other hypermetabolic lesion, especially in the pelvic and abdominal cavity. Fine needle aspiration cytology revealed metastatic carcinoma. The serum level of CA-125 was elevated to 43.8U/mL, whereas other tumor markers (CA 19-9, CEA) were in the normal range. She underwent a revision of selective neck lymph node dissection for the cervical neck levels I, II, and III, and on the review of surgical pathology, metastatic carcinoma was suspected. Thus, we performed immunohistochemical staining for the tissue; as a result, it was finally diagnosed as metastatic ovarian cancer (positive for CK7, ER and PR, and negative for CK20). Adjuvant chemotherapy (Paclitaxel+Carboplatin) was planned on the tumor board, and the patient successfully received chemotherapy.

• 한국전기전자재료학회논문지
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• 제30권6호
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• pp.361-365
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• 2017

In this paper, we investigated the effect of Co content on the microstructural and electrical properties of $Ni_{0.79}Mn_{2.21-x}Co_xO_4$ (x=0 to 0.25) specimens. Solid-state reaction was used to prepare the bulk specimens. XRD (X-ray diffraction) patterns showed that all compositions had a cubic spinel phase. As a result of the microstructural properties, FE-SEM(field-emission scanning electron microscopy) analysis showed a dense structure, and the mean grain size increased from $5.24{\mu}m$ to $7.33{\mu}m$ with an increase of Co content from x=0 to 0.25. All specimens exhibited the typical NTC thermistor characteristics as the electrical resistance exponentially decreased with increasing temperature. The resistivity and the B-value of $Ni_{0.79}Mn_{1.96}Co_{0.25}O_4$ were $2959{\Omega}{\cdot}cm$ and 3719, respectively.

• 대한기계학회논문집A
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• 제39권12호
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• pp.1199-1206
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• 2015

본 연구는 경유와 바이오디젤(대두유) 혼합연료의 디젤엔진 배기특성을 조사하였고, 연료 혼합비는 BD(biodiesel)3, BD5, BD20, BD50 및 BD100이며, 분사압력 조건을 400 bar, 600 bar, 800 bar, 1000 bar 및 1200 bar로 변화시켰다. 그리고 연료 혼합비 및 분사압력에 따른 엔진배출물인 NOx와 Soot의 정량적인 분석을 위해 통계학에 기초한 피어슨 상관계수와 스피어만 상관계수를 이하였다. 본 연구의 결과로서 실험변수인 혼합비와 분사압력에 대한 NOx 및 Soot 발생량의 피어슨 상관계수는 -0.811이며, 스피어만 상관계수는 -0.884로 NOx와 Soot 발생량 관계가 선형적이며, 이것은 trade-off관계를 나타낸다. 또한 각각의 분사압력 조건에서 피어슨 상관계수가 음의 상관 관계를 나타내며 이것은 NOx와 Soot 배출관계가 반비례적인 것을 나타낸다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권12호
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• pp.1742-1747
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• 2012

A total of 96 growing pigs ((Landrace${\times}$Yorkshire)${\times}$Duroc; BW = $26.58{\pm}1.41$ kg) were used in a 6-wk feeding trail to evaluate the effects of fermented chlorella (FC) supplementation on growth performance, nutrient digestibility, blood characteristics, fecal microbial and fecal noxious gas content in growing pigs. Pigs were randomly allotted into 1 of 4 dietary treatments with 6 replicate pens (2 barrows and 2 gilts) per treatment. Dietary treatments were: i) negative control (NC), basal diet (without antibiotics); ii) positive control (PC), NC+0.05% tylosin; iii) (fermented chlorella 01) FC01, NC+0.1% FC, and iv) fermented chlorella 02 (FC02), NC+0.2% FC. In this study, feeding pigs PC or FC01 diets led to a higher average daily gain (ADG) and dry matter (DM) digestibility than those fed NC diet (p<0.05), whereas the inclusion of FC02 diet did not affect the ADG and DM compared with the NC group. No difference (p>0.05) was observed on the body weight, average daily feed intake (ADFI), gain:feed (G:F) ratio, the apparent total tract digestibility of N and energy throughout the experiment. The inclusion of PC or FC did not affect the blood characteristics (p>0.05). Moreover, dietary FC treatment led to a higher (p<0.05) lactobacillus concentration and lower E. coli concentration than the NC treatment, whereas the antibiotic supplementation only decreased the E. coli concentration. Pigs fed FC or PC diet had reduced (p<0.05) fecal $NH_3$ and $H_2S$ content compared with those fed NC diet. In conclusion, our results indicated that the inclusion of FC01 treatment could improve the growth performance, nutrient digestibility, fecal microbial shedding (lower E. coli and higher lactobacillus), and decrease the fecal noxious gas emission in growing pigs when compared with the group fed the basal diet. In conclusion, dietary FC could be considered as a good source of supplementation in growing pigs because of its growth promoting effect.

• 환경영향평가
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• 제2권2호
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• pp.1-11
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• 1993

Most developing countries are experiencing rapid urbanization and the associated growth of industry and services. Cities are currently absorbing two-thirds of the total population in the developing world. Korea has about 85 percent of urban dwellers. World population will shift from being predominantly rural to predominantly urban around the turn of the century. Although cities play a key role in development process and make more than a proportionate contribution to national economic growth, especially cities are also the main catalysts of economic growth in developing countries, they can also be unhealthy, inefficient, and inequitable places to live. Most developing countries are increasingly unable to provide basic environmental infrastructure and services, whether in the megacities or in secondary urban centers. Of particular concern is the strain on natural resources brought by the increasing number of people, cars, and factories. They are generating ever greater amounts of urban wastes and emissions. They also exceed the capacity of regulatory authorities to control them and of nature to assimilate them. The environmental consequences are translated into direct negative impacts on human health, the quality of life, the productivity of the city, and the surrounding ecosystems. Environmental degradation threatens the long tenn availability and quality of natural resources critical to economic growth. Cities, with their higher and growing per capita energy use for domestic, industrial, and transport purpose also contribute a disproportionate share of the emission leading to global warming and acid rain. An important priority is to develop strategic approaches for managing the urban environment. The design of appropriate and lasting strategic responses requires first an understanding of the underlying causes of urban environmental deterioration, it is necessary that longer tenn objectives should be set for urban area to avoid irreversible ecological damage and to ensure lasting economic development. As a means to the preventive policies against the adverse effect, environmental impact assessment (EIA) serve to identify a project's possible environmental consequences early enough to allow their being taken into consideration in the decision making process for urban planning. This paper describes some considerations of EIA for urban planning-scoping, assessment process, measurement and prediction of impacts, pollution controls and supervision, and system planning for environmental preservation.