• Journal of Wetlands Research
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• v.19 no.1
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• pp.1-15
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• 2017

Wetland function assessment is not only a basic step to understand wetland ecosystems in detail but also an important process as a base of the term, ecosystem service to recognize wetland ecosystems as valuable and useful resources and goods for human being. WET (wetland evaluation technique), EMAP (environmental monitoring assessment program)-wetlands, and HGM (hydrogeomorphic method) were developed as pioneer wetland function assessments in U.S. at the end of $20^{th}$-century. RAMs (rapid assessment methods) became a major function assessment tool which is relatively simpler and easier assessment tool at the beginning of $21^{th}$-century. After that, the hierarchy of three levels of assessment (landscape assessment, rapid assessment, and intensive assesment) has been prepared and strategically utilized according to the objectives and purposes of function assessments. In South Korea, RAM and HGM were used to assess wetland functions with reforming a couple of items and contents at 2001. And, modified and reformed function assessments have been developed to complement and improve upon the existing RAMs and HGMs. Via the trend analysis on wetland function assessments, some needs which require supplements in terms of function assessment are pointed out: 1) wetland function assessments using useful indicators such as birds are needed with considering our environmental characteristics. 2) optimized wetland function assessments for coastal wetlands are also needed. 3) the network construction and further expansion to lead communications and co-operations between researchers and policy makers is needed in the field of wetland function assessment.

• Economic and Environmental Geology
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• v.42 no.3
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• pp.261-272
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• 2009

An experimental study of the accelerated weathering was performed to investigate the variations of physicomechanical properties of deteriorated rocks due to freeze-thaw weathering for the Jurassic granite specimens from Wonju, Gangwon-do. Each complete cycle of freeze and thaw was lasted 24 hours, comprising 2 hours saturating in vacuum chamber, 8 hours freezing at -20$\pm1^{\circ}C$ and 14 hours thawing at room temperature. Freeze-thaw cycles were implemented with measuring the index physical properties as well as geometries of microfractures. The seismic velocity was found to decrease with increasing freeze-thaw cycles. On the other hand, absorption tends to increase with freeze-thaw cycles. In the end, it was concluded that variations of the index properties of deteriorated specimen depend on its initial properties and flaws in rock. The size and density of the traces of the microfracture on slab specimen were changed continuously with increasing freeze-thaw weathering. The results obtained in this study show that the box fractal dimension($D_B$) has the strong capability of quantifying the combined effect of size and density of the microfractures.

• Tunnel and Underground Space
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• v.19 no.2
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• pp.146-157
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• 2009

An experimental study of accelerated weathering on mudstone sample specimens from Haman, Gyeongnam was performed to investigate the variations of physico-mechanical properties of deteriorated rocks due to freeze-thaw weathering. Each complete cycle of freeze and thaw lasted 24 hours, comprising 2 hours of saturating in vacuum chamber, 8 hours of freezing at $-16{\pm}1^{\circ}C$ and 14 hours of thawing at room temperature. Total of 55 cycles of freeze-thaw were completed with measuring the index properties as well as geometries of microfractures. The measured specific gravity and P-wave velocity found to decrease with increasing freeze-thaw cycles. On the other hand, absorption ratio and effective porosity were continuously increased with increasing freeze-thaw cycles. It was found that the index properties of deteriorated sample specimen depend on its initial properties and flaws in rock. The size and density of the traces of the microfracture on slab specimen exhibited abrupt changes after 30 cycles of freeze-thaw weathering. The results obtained in this study show that the box fractal dimension($D_B$) given in this paper has the strong capability of quantifying the size and density of the microfracture.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1067-1071
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• 2004

도시 유역의 물순환 특성을 종합적으로 이해하기 위해서는 갈수량 자료의 구축이 필수적이다. 하지만 지금까지의 인구는 주로 치수분야에 한정되어 대부분의 자료 또한 홍수기에 대해서만 자료가 구축되어 있으며 상대적으로 갈수기에 내한 자료와 관련 연구는 부족한 편이다. 본 연구에서는 청계천 유역의 기존 수문자료를 이용하여 유역의 유출 특성을 분석하고 갈수량을 측정하여 청계천 유역의 물순환 특성을 파악하기 위한 기초자료를 구축하였다. 청계천은 서울의 서북쪽에 위치한 인왕산과 북한산의 남쪽 기슭, 남산의 북쪽 기슭에서 시작하여 서에서 동으로 종로, 세운상가, 동대문 등 서울의 도심부를 흐르는 유로연장 13.75 km, 유역 면적 $50.96 km^2$의 도시하천으로 중량천의 제1지류인 지방2급 하천이며, 정릉친, 성북천을 제1지류, 월곡천을 제2지류로 포함한다. 청계천은 도시화로 인해 1950년대부터 1970년대까지 점차 복개되었다가 2003년 7월부터 5.9 km의 본류구간에 대한 복원공사가 진행 중이다. 청계천은 홍수기 이후 유량이 급격히 줄어 11월 이후에는 다음 홍수기까지 강바닥이 완전히 들어나는 일종의 간헐천으로 홍수기를 제외한 시기의 자료는 전무한 실정이다. 본 연구에서는 유역내 8개의 모니터링 지점을 선정하여 2003년 9월 이후, 월 2회 이상 갈수량 자료를 현장 측정${\cdot}$분석하였다. 청계천 유역은 복원공사 완공 후에는 유역의 물순환 특성이 대폭 바뀔 것이 예상되는 지역으로 본 연구에서 구축된 갈수량 자료는 청계천 유역의 물순환계 변화를 분석하고 건전한 물순환 체계의 유지${\cdot}$관리를 위한 기본 자료가 될 것으로 판단된다., 바늘꽃과, 속새과, 십자화과, 장미과, 사초과, 삼과, 현삼과, 닭의장풀과가 각 1종씩 조사되었으며, 조사지점(II)인 1km지점에서는 15과 26종으로, 벼과가 4종, 마디풀과, 국화과가 3종, 버드나무과, 십자화과, 콩과가 2종씩, 바늘꽃과, 속새과, 자라풀과, 장미과, 사초과, 백합과, 현삼과, 골풀과, 닭의장풀과가 각 1종씩으로, 조사지점( I )보다 좀 더 많은 종이 분포하는 것으로 조사되었다. 또한 어류는 조사지점( I )에서 3회에 걸쳐 총 396개체가 채집되어 3목 8과 21종이었다. 이 중 한국 고유종은 11종이었고, 외래 어종은 검정우럭과 2종이 조사되었으며, Zacco platypus(피라미), Zacco temmincki(갈겨니), Acheilongnathus koreanus(칼납자루), Odontobutis platycephala(동사리), Coreoleuciscus splendidus(쉬리) 순으로 분포하고 있었고, Acheilognathus signifer(묵납자루)는 댐 건설 전에는 많이 분포하였으나 현장조사에서 서식을 확인 할 수 언어 개체수의 큰 감소내지 멸종된 것으로 추정되었다.에서 동시에 시행하였다. 수술 후 1년 내 시행한 심초음파에서 모든 환아에서 단지 경등도 이하의 승모판 폐쇄 부전 소견을 보였다. 수술 후 조기 사망은 없었으며, 합병증으로는 유미흉이 한 명에서 있었다. 술 후 10개월째 허혈성 확장성 심근증이 호전되지 않아 Dor 술식을 시행한 후 사망한 예를 제외한 나머지 6명은 특이 증상 없이 정상 생활 중이다 결론: 좌관상동맥 페동맥이상 기시증은 드물기는 하나, 영유아기에 심근경색 및 허혈성 심근증 또는 선천성 승모판 폐쇄 부전등을 초래하는 심각한 선천성 심질환이다

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.809-813
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• 2004

강우시 유역 내에서 발생하는 수문특성을 구명하고자 하는 연구는 지속적으로 진행되고 있다. 특히 최근 몇년간 집중호우로 인한 홍수피해가 매우 실각한 수준으로 발생하였고, 이에 지방 소하천을 포함한 전국의 하천정비사업이 새로운 설계홍수빈도를 토대로 진행되고 있다. 우리나라의 강우특성은 여름철에 편중되는 특성을 지니고 있어 홍수시의 홍수방어 대책 등 치수에 많은 어려움이 있는 것이 현실이다. 집중호우로 인한 피해는 전 세계적인 문제로 제기되고 있으며, 이에 강우-유출 관계를 규명하고자 하는 노력이 지속적으로 이루어지고 있다. 강우-유출과정은 시간적, 공간적 다변성을 지닌 수문학적 인자에 의해 좌우되기 때문에 이러한 문제를 해결하기 위해 다년간의 강우-유출 자료를 바탕으로 알고리즘을 생성하고, 이를 바탕으로 정확한 모의가 가능한 수문 모형 및 시스템들을 개발하는데 노력을 기울이고 있다(심순보 등, 1998, 신사철 등, 2002). 그러나 이러한 모형들은 많은 매개변수와 다양한 정보들을 필요로 하게 되어 이들을 처리하는데 많은 어려움이 따른다. 따라서 최근에는 GIS(Geographical Information System)를 활용하여 유역과 분수계를 결정하고 하천형태학적인 특성인자를 추출하는 자동화된 유역정보 추출기술 개발에 대한 관심이 집중되고 있다(Bhaskar, 1992, Francisco, 1995, Yeon, 1999). 이에 본 연구에서는 GIS기법을 이용하여 지형자료로부터 하천연장, 배수면적, 지체시간, 도달시간 등 유역내의 분포형 수문매개변수를 추출하였고 추출된 매개변수를 통해 강우-유출식을 적용하여 분포형 유출량을 산정하는데 활용하고자 한다.ansverse Mercatro) 지구좌표계의 DEM 자료로 변환하였다. 또한 유역의 고도차를 이용한 흐름특성 분석을 위해 수치고도자료를 이용하여 유역흐름특성을 분석할 수 있는 TOPAZ(Topographic PArameteri-Zation) 프로그램을 이용하였다. TOPAZ 프로그램을 통해 분석된 각 격자별 분포형 수문 매개변수는 적합한 관계식을 통해 분포형 유출량을 모의하는데 적용된다.다 정확한 유입량 예측이 가능할 것으로 사료된다.이 작은 오차를 발생하였으며, 전체적으로 퍼프 모형이 입자모형보다는 훨씬 적은 수의 계산을 통해서도 작은 오차를 나타낼 수 있다는 것을 알 수 있었다. 그러나 Gaussian 분포를 갖는 퍼프모형은 전단흐름에서의 긴 유선형 농도분포를 모의할 수 없었고, 이에 관한 오차는 전단계수가 증가함에 따라 비선형적으로 증가하였다. 향후, 보다 다양한 흐름영역에서 장${\cdot}$단점 분석 및 오차해석을 수행한 후에 각각의 Lagrangian 모형의 장점만을 갖는 모형결합 방법을 제시할 수 있을 것으로 판단된다.mm/$m^{2}$로 감소한 소견을 보였다. 승모판 성형술은 전 승모판엽 탈출증이 있는 두 환아에서 동시에 시행하였다. 수술 후 1년 내 시행한 심초음파에서 모든 환아에서 단지 경등도 이하의 승모판 폐쇄 부전 소견을 보였다. 수술 후 조기 사망은 없었으며, 합병증으로는 유미흉이 한 명에서 있었다. 술 후 10개월째 허혈성 확장성 심근증이 호전되지 않아 Dor 술식을 시행한 후 사망한 예를 제외한 나머지 6명은 특이 증상 없이 정상 생활 중이다 결론: 좌관상동맥 페동맥이상 기시증은 드물기는 하나, 영유

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.4
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• pp.127-134
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• 2012

This study analyzed the present status of services by fire-suppression mobilization time of fire station where is located in Jinju city, by using network analysis of GIS targeting fire station(five 119 safety centers, one 119 division) in Jinju city area. As a result, it was indicated to be 15.9% in the ratio with less than 5 minutes of mobilization time, 34.7% in the ratio with less than 8 minutes, 94% in the ratio with less than 20 minutes out of the whole fire service area in Jinju city. Even districts with more than 20 minutes were analyzed to reach 6%. Especially, to solve vulnerability to approach the fire service in uptown districts(Jinseong, Jisu, Sabong, Ilbanseong, the whole area of Ibanseong), the 119 division is installed more to be operated. However, accessibility is still remaining in low level. Also, in case of 119 safety center of Cheonjeon, the national industrial complex and the general industrial complex are being formed on a large scale. However, analyzing the fire service level in the corresponding area, the districts with more than 8 minutes and less than 20 minutes were existing broadly. In consequence of analyzing the fire service area in Jinju city with the fire-suppression mobilization time as the above, the fire service level is failing to escape largely from the status prior to the urban-rural consolidation compared to what the jurisdictional area was largely expanded by which the administrative districts were integrated by the urban-rural consolidation in locally small-and medium-sized city. Thus, there is a need of a measure for improving this.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.2 s.117
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• pp.158-165
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• 2007

In this paper, the circularly polarized $4{\times}4$ array antenna is proposed for the X-band. A single antenna consists of square patch and unequal cross-aperture coupled feeding. The RHCP(Right Handed Circularly Polarization) is generated by unequal cross-aperture coupled feeding. By reducing space among elements of way antenna from 0.8 ${\lambda}_0$ to 0.45 ${\lambda}_0$, the mounting area of array antenna is miniaturized. The $2{\times}2$ array antenna is designed using sequential rotation feeding network. The good level of gain, axial ratio, and impedance bandwidth are achieved. The $4{\times}4$ array antenna is extended by ${\lambda}/4$ transformer and T-junction power divider. The simulated maximum radiation gain is 15.09 dBi at 10 GHz. The simulated 3 dB Axial Ratio bandwidth is from 9.05 to 10.4 GHz(13.5%). Also the measured impedance bandwidth($VSWR{\leq}2$) of manufactured $4{\times}4$ array antenna is from 8.45 to 11.84 GHz(33.9%). The measured maximum radiation gain is 11.10 dBi at 10 GHz. The measured 3 dB Axial Ratio bandwidth is from 9.42 to 10.47 GHz(10.5%).

• The Journal of the Petrological Society of Korea
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• v.9 no.1
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• pp.40-50
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• 2000

This study is aimed at elucidating the source rocks of the Hayang strata in the northeastern part of the Gyeongsang Basin. Zircon morphology was analyzed for sandstones from the Iljig, Hupyeongdong, and Jeomgog formations of the Hayang Group and Precambrian gneisses and Jurassic granites. Generally, the composite zircon crystals extracted from the basement rocks and the Hayang Group sandstones show short prismatic to middle prismatic shapes. {110)={100) prism type is dominant and (101) pyramid is the average of the zircon morphology data. Zircon index@) and the shape trend characteristics clearly show that the zircon crystal forms of the Iljig and Hupyeongdong sandstones are dominantly similar to those of the biotite banded gneiss and granite gneiss of Precambrian age. Zircon morphology of the Jeomgog sandstones is dominantly similar to those of the Jurassic granites. Referring to the reported paleocurrent result, the source rocks of the Iljig and Hupyeongdong formations are mainly the Precambrian gneisses distributed in the southeastern and northeastern parts, respectively. And Jeomgog sandstones were mainly derived from Cheongsong granite at Cheongsong uplift region in the eastern part. At the time of completion of the Hupyeongdong sedimentation, the Precambrian basement rocks were severely eroded and formed low topography. During the Jeomgog period, the Jurassic granites which intruded the Precambrian basement began to crop out on the surface. The basin widely extended toward the east and the exposed Jurassic granite of Cheongsong uplift region actively supplied the sediments to the basin.

• Journal of Environmental Policy
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• v.13 no.3
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• pp.3-19
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• 2014

Large-scale unband development resulted from the rapid economic growth in the Republic of Korea has brought about the habitat destruction for the native animals and plants living in forest and farmland. In order to resolve this problem, it is necessary to consider the natural ecosystem as an organism and to preserve the natural ecosystem by managing ecologically significant habitat consistently. Especially, the local governments should be able to establish regional ecologic networks in consideration of the ecological connectivity and the environmental and ecological excellence, and to reflect them into the local development plans. In regard to this, the methods of the regional ecological network establishment was presented, making use of the results including the national ecological network which assessed the ecological connectivity of the nation and the environmental and ecological assessment results of the Environmental Conservation Value Assessment Map which was designed to analyze and assess the national environmental and ecological values quantitatively. Making use of the case of Gyeongsangnam-do; the results presented that the existing national ecological network in the core region has expanded from $2,986km^2$ to $4,049km^2$ and the existing national ecological network in the buffer region has expanded from $2,940km^2$ to $3,006km^2$. Referring to the regional ecological network in the process of the local development plans could contribute to the increase in biodiversity and the integrated local environmental management including the ecosystem preservation.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.2
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• pp.63-70
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• 2014

Design sensitivity analysis and topology design optimization for a piezoelectric crystal resonator are developed. The piezoelectric crystal resonator is deformed mechanically when subjected to electric charge on the electrodes, or vice versa. The Mindlin plate theory with higher-order interpolations along thickness direction is employed for analyzing the thickness-shear vibrations of the crystal resonator. Thin electrode plates are masked on the top and bottom layers of the crystal plate in order to enforce to vibrate it or detect electric signals. Although the electrode is very thin, its weight and shape could change the performance of the resonators. Thus, the design variables are the bulk material densities corresponding to the mass of masking electrode plates. An optimization problem is formulated to find the optimal topology of electrodes, maximizing the thickness-shear contribution of strain energy at the desired motion and restricting the allowable volume and area of masking plates. The necessary design gradients for the thickness-shear frequency(eigenvalue) and the corresponding mode shape(eigenvector) are computed very efficiently and accurately using the analytical design sensitivity analysis method using the eigenvector expansion concept. Through some demonstrative numerical examples, the design sensitivity analysis method is verified to be very efficient and accurate by comparing with the finite difference method. It is also observed that the optimal electrode design yields an improved mode shape and thickness-shear energy.