• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1455-1459
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• 2005

K-WEAP(Korea-Water Evaluation And Planning System)은 유역의 물이용 순환체계를 컴퓨터 프로그램으로 구현하고, 수량, 수질, 환경, 수요관리 등을 종합적으로 고려하여 통합수자원계획 수립을 지원하는 전문 모형으로서, 과학기술부와 건설교통부가 공동으로 지원하는 21세기 프론티어 사업인 수자원의 지속적 확보기술사업단의 연구비 지원에 의하여 SEI-B(Stockholm Environment Institute-Boston Center)와 한국건설기술연구원이 공동으로 개발한 모형이다. K-WEAP의 대부분 기능은 기존의 SEI-B가 개발한 WEAP(Water Evaluation And Planning System)에 기반을 두고 있지만, 월 단위 물수지 분석뿐만 아니라 5일 및 임의 시간 단위 물수지분석이 가능하고 물공급 안전도평가와 하천수질모의가 가능하다는 점에서 기존의 WEAP과는 다르며 메뉴와 도움말이 모두 한글로 작성되어있어 국내 사용자들이 이용하기 용이하다. K-WEAP의 기능은 단계적으로 보완 및 개선이 이루어지고 있으며, 현재는 1단계 개발이 끝난 후 2단계 기능개선 작업을 수행하고 있다. 2단계에서 개선하게 될 주요부분은 물수지모형의 개선과 하천수질모형의 개선, 편익산정모형의 개발, 의사결정지원 기능을 고려하는 사용자인터페이스 개선 등이 포함되어 있으며, 2단계 1차 년도에서는 물수지모형과 하천수질모형의 부분적인 개선과 함께 의사결정지원 기능을 고려하는 사용자 인터페이스의 부분적인 개선을 시도하였다. 물수지모형의 개선에서는 하수처리장의 회귀수를 수요처에서 직접 이용할 수 있도록 하였으며, 하천수질모형의 개선부분에서는 기온과 풍속 등의 기후자료를 이용한 수온 모의모형을 개발하였다. 또한, 사용자 인터페이스 부분에서는 사용자의 의사결정을 지원하기 위해 하천유량과 수질 등에 대한 초과비율그래프 조회 기능과 결과를 지도상에서 확인할 수 있는 지도보기기능, 사용자가 필요한 자료를 요약하여 조회할 수 있는 사용자 정의보고서 작성기능을 추가하였다. 개선된 기능을 통해 사용자는 보다 편리한 환경에서 모형을 구동하고 구동결과를 평가 할 수 있을 것으로 기대된다.

• Korean Journal of Biological Psychiatry
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• v.18 no.1
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• pp.25-35
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• 2011

Objectives : Cerebral laterality is thought to be an important marker for neurodevelopment. Prenatal testosterone could influence both cerebral laterality and 2nd to 4th finger length ratio(2D : 4D). EEG coherence and 2D : 4D were examined to investigate the relationship between prenatal testosterone level and cerebral laterality. Methods : EEG was recorded in 24 healthy subjects in the eyes closed resting state. Differences in 2D : 4D finger ratio were used to discriminate "masculine finger type" and "feminine finger type" groups. The 2D : 4D ratio was lower and greater than one for the "masculine finger type" group and "feminine finger type" group, respectively. We used coherence analysis to estimate the cortical functional connectivity. Results : There were statistically meaningful relationships among cerebral functional connectivity, sex and finger ratio. Man and masculine finger type group showed higher intra-hemispheric coherence than those of woman and feminine finger type group. Woman and feminine finger type group showed higher inter-hemispheric coherence than those of man and masculine finger type group. Conclusions : These results imply that prenatal testosterone might act as important determinants of cerebral laterality. Further examination of the relationship between 2D : 4D and EEG coherence in schizophrenia could give some clues for the neurodevelopmental hypothesis of schizophrenia genesis.

• Applied Biological Chemistry
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• v.34 no.2
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• pp.110-116
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• 1991

As the model compounds, citral and n-octanol which possess similar characteristics and structures of low molecular weight insect pheromones and $({\pm})-5-hydroxy-4-methyl-heptan-3-one$ which shows the aggregation pheromones activity of the rice weevil and the maize weevil were microencapsulated with low molecular weight polyethylene(LMPE) and urea-formaldehyde resin as wall materials. The core materials were microencapsulated as small particles in LMPE and urea-formaldehyde resin polymers and the microencapsulated polymers were white powders. And the polymer made from urea-formaldehyde resin was better than that from LMPE as wall material. The slow releasing effect and the releasing patten of the microencapsulated core materials were examined by solvent extraction method and headspace sampling method. Citral and n-octanol and $({\pm})-5-hydroxy-4-methyl-heptan-3-one$ were release more than 40 days and 15 days, respectively. The releasing pattern of urea-formaldehyde resin microcapsules showed rather smooth decrease than that of LMPE and was maintained at steady level longer.

• Applied Chemistry for Engineering
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• v.3 no.3
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• pp.430-439
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• 1992

To improve the adhesion of interface and dispersion of glass beads in the composite, HDPE filled with glass brads, we encapsulated the g1ass beads with polymer by phase separation method using complex coacervation in organic solvent. EMAA and EAA were used as the polymeric wall materials. The microencapsulation efficiency and morphology were observed by thermogravimetric analysis and SEM, respectively. And also we investigated the physical and dynamic mechanical properties of the composite as the function of the beads contents and microencapsulation efficiency. Compared with the composite containing non-treated glass beads, the decrease in tensile strengthe of the composites containing the encapsulated glass beads become markedly small, and about 30~40% Increase in tensile modulus was observed. From the results of the dynamic mechanical analysis, it was found that the adhesion of interface and dispersion could be improved upon encapsulation.

• Korean Journal of Materials Research
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• v.11 no.1
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• pp.8-14
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• 2001

Microstructural evolution and creep failure behavior of GTD 111 have been studied. Solidification and precipitation behaviors of the alloy during casting have been analyzed by microstructural observations. It has been found that MC carbides solidify just before the $\gamma$/$\gamma$' eutectic solidification. The ηphase was found to be formed by transformation of Ti-rich $\gamma$'phase. PFZ has formed in the vicinity of the transformed $\eta$ phase. A few MC particles, which have been identified as TaC, precipitated within the PFZ. Creep failure along grainboundary was dominant at and above $871^{\circ}C$. Creep failure above$ 871^{\circ}C$ was caused by the propagation of surface cracks and internal cracks. Creep crack has initiated at the microporosities embedded on the grainboundary. The $\eta$phase and PFZ have been found to be little or no effect on creep crack initiation.

• The Journal of the Petrological Society of Korea
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• v.7 no.1
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• pp.1-14
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• 1998

Dangsanbong volcano, which is located on the coast of the western promontory of Cheju Island, occurs in such a regular pattern on the sequences which represent an excellent example of an eruptive cycle. The volcano comprises a horseshoe-shaped tuff cone and a younger nested cinder cone on the crater floor, which are overlain by a lava cap at the top of the cinder cone, and wide lava plateau in the moat between two cones and in the northern part. The volcanic sequences suggest volcanic processes that start with Surtseyan eruption, progress through Strombolian eruption and end with Hawaiian eruption, and then are followed by rock fall from sea cliff of the tuff cone and by air fall from another crater. It is thought that the eruptive environments of the tuff cone could be mainly emergent because the present cone is located on the coast, and standing body of sea water could play a great role. It is thought that the now emergent part of the tuff cone was costructed subaerially because there is no evidence of marine reworking. The emergent tuff cone is characterized by distinctive steam-explosivity that results primarily from a bulk interaction between rapidly ascending magma and external water. The sea water gets into the vent by flooding accross or through the top or breach of northern tephra cone. Dangsanbong tuff cone was constructed from Surtseyan eruption which went into with tephra finger jetting explosion in the early stage, late interspersed with continuous upruch activities, and from ultra-Surtseyan jetting explosions producting base surges in the last. When the enclosure of the vent by a long-lived tephra barrier would prevent the flooding and thus allow the vent to dry out, the phreatomagmatic activities ceased to transmit into magmatic activity of Strombolian eruption, which constructed a cinder cone on the crater floor of the tuff cone Strombolian eruption ceased when magma in the conduit gradually became depleted in gas. In the Dangsanbong volcano, the last magmatic activity was Hawaiian eruption which went into with foundation and effusion of basalt lava.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.5
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• pp.229-234
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• 2017

In this study, TiAl alloy was fabricated by a centrifugal casting method for turbo charge of automotive. Optimum conditions for defectless morphology using various ceramic mold were investigated. The crystal structure, microstructure, and chemical composition of the TiAl prepared by centrifugal casting were studied by X-ray diffractometer (XRD), optical microscopy (OM), field emission scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS), microvickers hardness analyzer (HV). Two kinds of dendrite structures were observed with 4-fold and 6-fold symmetries. The FE-SEM, EDS and HV examinations of the as-cast TiAl showed that the thickness of the oxide layer (${\alpha}$-case) was typically less than $50{\mu}m$.

• Polymer(Korea)
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• v.28 no.6
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• pp.460-467
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• 2004

The polymer blends of waste poly(vinyl chloride) (RPVC) and waste polyethylene (RPE) were prepared by melt mixing. Their morphologies and rheological properties were investigated and torque changes were also measured. Comparing the torques calculated by the log additivity rule with measured torque changes, the polymer blends showed the large negative deviation behavior (NDB) due to their incompatibility. The shear viscosities of the blends decreased with increasing shear rates, showing shear thinning behavior. The shear viscosity of the blends with compatibilizer was larger than that of the blends without compatibilizer. SEM micrographs of the strands after measurement showed that the domain size of the blends was slightly enlarged with increasing the shear rate. Also, RPVC domain size was larger in the core-sections of the strands from capillary viscometer than in the surface region.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.05a
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• pp.103-104
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• 2006

고체연료 성상별 연소시 굴뚝에서 배출되는 입자상물질의 농도는 섬유류(86.8mg/m$^3$) > PP 마대류(26.51mg/m$^3$) > 합성수지류(16.71mg/m$^3$) > 우레탄(11.17mg/m$^3$) > 목재류(10.92mg/m$^3$) > 종이류(2.61mg/m$^3$)의 순으로 나타났다. 특히 폐섬유 소각시 입자상물질 중 중금속 함유농도는 Pb의 경우 기타 고체연료 연소시 함유농도비가 0.4% 이하인 반면에 폐섬유 소각시 6.6%인 5.72mg/m$^3$로 높게 나타났으며, Cd 또한 1.4%인 1.24mg/m$^3$로 높게 나타났다.

• 한국벤처창업학회:학술대회논문집
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• 2021.11a
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• pp.145-154
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• 2021

현재 우리나라 한우고기 가격은 코로나 19상황, 아프리카 돼지열병 발생, 쇠고기 수급부족 등 내외부적인 환경적인 문제로 인하여 급상승하고 있다. 한우고기 수출은 2015년 홍콩을 시작으로 마카오, 캄보디아 등으로 수출 영토가 넓어졌지만 수출량은 2018년을 정점으로 감소하고 있는 추세이다. 이런 상황에서 우리나라 한우고기의 활성화를 위해 수출전략을 재검토해야할 시점이 온 것으로 판단된다. 따라서 본 연구에서는 2015년 우리나라 한우고기의 첫 수출 이후 7년이 흐르고 한우산업의 불확실성이 증가하고 있는 현 시점에서 북경, 상해, 홍콩 3개 도시를 대상으로 쇠고기 시장조사 실시를 통해 우리나라 한우고기의 가격경쟁력을 비교·분석 하였다. 그 결과, 한우고기 가격 급상승에도 불구하고 북경, 상해, 홍콩 3개 도시에서 가격경쟁력이 확보된 것으로 나타났다.