• 대한기계학회논문집A
• /
• 제27권6호
• /
• pp.981-986
• /
• 2003

In order to investigate the possibility of processing of brittle material by ball impact, the effects of boundary conditions about impact damage of soda-lime glass by small spheres were evaluated experimentally. It was investigated that crack appearance developed in soda-lime glass with boundary conditions of without sealing, single-sealing and double-sealing by impact velocity. The double-sealing was most effective in the development of perfect cone than other boundary condition. In case of double-sealing condition, PVC and Polyurethane sealing were more effective in producing a perfect cone formation than other sealing materials. The impact velocity range over which perfect cones were formed was influenced by both the contact area and diameter of impact particle.

• 한국환경복원기술학회지
• /
• 제21권5호
• /
• pp.39-60
• /
• 2018

National parks are designated for the purpose of maintenance, conservation and utilization of different habitats. Therefore, it is necessary to select habitats of a high value as a protected area in order to balance conservation and development. However, the existing national park boundary adjustment and new designation criteria only focused on the endangered species and protected area, without proper evaluation of the habitat value of actual species. Therefore, this study aims to quantitatively evaluate habitat function in terms of biodiversity and habitat value, so that it can be referred to for the designation and boundary adjustment of national parks. We assessed species diversity and habitat values for each of the habitat types, for mammals only, as they are able to choose preferred habitats. In order to evaluate biodiversity, we used Maxent to derive species richness map and used InVEST's Habitat quality model to evaluate habitat value. As a result of evaluation, species richness was high in the national park boundary area. Also, even if the same edge is adjacent to the development area depending on the land cover, the species richness is low. Compared with Wolaksan and Sobaeksan National Park, the species richness and habitat value of the northern area, which is connected with other forests, were higher than those of the southern area where roads were developed. Therefore, it is expected that the use of the result of this study for the national park boundary adjustment and management will enhance the function of the national park as a habitat.

• 대기
• /
• 제22권4호
• /
• pp.387-400
• /
• 2012

This study aims at examining the sensitivity of numerical simulations to the resolution of initial and boundary data, and to an application of WRF (Weather Research and Forecasting) 3DVAR (Three Dimension Variational data Assimilation). To do this, we ran the WRF model by using GDAS (Global Data Assimilation System) FNL (Final analyses) and the KLAPS (Korea Local Analysis and Prediction System) analyses as the WRF's initial and boundary data, and by using an initial field made by assimilating the radar data to the KLAPS analyses. For the sensitivity experiment, we selected a heavy rainfall case of 21 September 2010, where there was localized torrential rain, which was recorded as 259.5 mm precipitation in a day at Seoul. The result of the simulation using the FNL as initial and boundary data (FNL exp) showed that the localized heavy rainfall area was not accurately simulated and that the simulated amount of precipitation was about 4% of the observed accumulated precipitation. That of the simulation using KLAPS analyses as initial and boundary data (KLAPC exp) showed that the localized heavy rainfall area was simulated on the northern area of Seoul-Gyeonggi area, which renders rather difference in location, and that the simulated amount was underestimated as about 6.4% of the precipitation. Finally, that of the simulation using an initial field made by assimilating the radar data to the KLAPS using 3DVAR system (KLAP3D exp) showed that the localized heavy rainfall area was located properly on Seoul-Gyeonggi area, but still the amount itself was underestimated as about 29% of the precipitation. Even though KLAP3D exp still showed an underestimation in the precipitation, it showed the best result among them. Even if it is difficult to generalize the effect of data assimilation by one case, this study showed that the radar data assimilation can somewhat improve the accuracy of the simulated precipitation.

• 한국지리정보학회지
• /
• 제25권4호
• /
• pp.19-31
• /
• 2022

우리나라 도시숲은 「도시숲 등의 조성 및 관리에 관한 법률」에 의거하여 자연공원을 제외한 모든 산림과 수목으로 정의되고 있으나, 일반적인 인식으로서의 도시 내 존재하는 숲의 개념과는 이질성이 있다. 본 연구에서는 도시숲을 "도시 내에 존재하는 산림과 수목"으로 규정하였으며, 도시의 경계를 설정하기 위한 시나리오를 제안하고 그에 따른 도시숲의 면적 변화를 모의하였다. 법률상 도시지역의 정의, WHO에서 제안한 주거지로부터 도시숲에 접근 가능한 거리(300m), 산림유역을 고려한 네 가지 시나리오를 설정하여 각 시나리오에 따라 도시숲의 양적 분포를 분석하였다. 첫 번째로 "용도지역상 도시지역"의 최외곽 경계와 연접하는 산림유역까지를 도시숲 경계로 규정한 경우, 도시숲 면적은 약 183만ha, 1인당 도시숲 면적은 약 386㎡로 분석되었다. 두 번째로 "용도지역상 도시지역"의 최외곽 경계로부터 300m 이내까지 도시로 규정하고 해당 경계와 연접한 산림유역 내에 존재하는 숲을 도시숲으로 규정한 경우, 도시숲 면적은 약 192만ha, 1인당 도시숲 면적은 약 405㎡로 분석되었다. 세 번째로 "행정구역 상 읍·동 지역"내 "용도지역상 도시지역"의 최외곽 경계와 연접하는 산림유역까지를 도시숲 경계로 규정한 경우, 도시숲 면적은 약 108만ha, 1인당 도시숲 면적은 약 230㎡로 분석되었다. 네 번째로 "행정구역 상 읍·동 지역" 내 "용도지역상 도시지역"의 최외곽으로부터 300m 경계와 연접하는 산림유역까지를 도시로 규정한 경우, 도시숲 면적은 약 120만ha, 1인당 도시숲 면적은 약 256㎡로 분석되었다. 이렇듯 도시의 정의에 따라 도시숲의 면적이 다양하게 추정될 수 있기 때문에, 국가통계를 집계하기 위해서는 도시에 대한 정의가 먼저 정립되어야 하고, 그에 따라 현실적·과학적 분석에 근거하여 도시숲의 면적이 산출되어야 한다.

• 한국환경과학회지
• /
• 제25권7호
• /
• pp.1029-1042
• /
• 2016

The initial and boundary conditions are important factors in regional chemical transport modeling systems. The method of generating the chemical boundary conditions for regional air quality models tends to be different from the dynamically varying boundary conditions in global chemical transport models. In this study, the impact of real time Copernicus atmosphere monitoring service (CAMS) re-analysis data from the modeling atmospheric composition and climate project interim implementation (MACC) on the regional air quality in the Korean Peninsula was carried out using the community multi-scale air quality modeling system (CMAQ). A comparison between conventional global data and CAMS for numerical assessments was also conducted. Although the horizontal resolution of the CAMS re-analysis data is not higher than the conventionally provided data, the simulated particulate matter (PM) concentrations with boundary conditions for CAMS re-analysis is more reasonable than any other data, and the estimation accuracy over the entire Korean peninsula, including the Seoul and Daegu metropolitan areas, was improved. Although an inland area such as the Daegu metropolitan area often has large uncertainty in PM prediction, the level of improvement in the prediction for the Daegu metropolitan area is higher than in the coastal area of the western part of the Korean peninsula.

• 인문언어
• /
• 제8집
• /
• pp.265-289
• /
• 2006

The geographical characteristics of Yeongdong(永同) the southernmost part of the Chungcheongbukdo province, has attracted attention among the academic circle as one of the dialectal contact regions since it adjoins the Gyeongsang and Jeolla dialects. Unlike the local language in Mooju (Jellado dialect) adjacent to the Southwest part, the local language in Yeongdong is quite different from that of Kimcheon (Gyeongsang dialect). More specifically, it is noteworthy that the boundary line of the Gyeongsang dialect is found in this region, which is different from the administrative division. In other words, the local language in Yeongdong is divided into the Chungcheong dialect and the Gyeongsang dialect, and furthermore each dialect region still has the characteristics of the other region's dialect. For example, the phonological structure of Yeongdong Chungcheongdo dialect has very unique characteristics of the fudged dialect, which is seemingly influenced by the Gyeongsang dialect. The present study is to define the bottom boundary line of the southeast area of the Chungcheong dialect by identifying the boundary line between the Gyeongsang dialect and the Chungcheong dialect, and to clarify its specific sound system generated by the contact of these two dialects. For this, the author collected and analyzed data of the local language around Yeongdong and adjacent areas. It was found that Cheongwha-ri, Deokjin-ri, and Sanjeo-ri at Yeongsan-myeon, and Mugeunjeom, Sangga-ri, and Jungga-ri at Yeongdong-eup, among the regions that belongs to Chungcheong dialect within the local language of Yeongdong, show the characteristics of the Gyeongsang dialect. Accordingly, the western areas of these villages become the southeast boundary line of the Chungcheong dialect. Also, the unique phonological characteristics of the Yeongdong Chungcheong dialect is affected by the Gyeongsang dialect, among which "rhythms, y deletion, nasal phoneme deletion, and w deletion" appeared. It is thought to be the unique fudged dialectal phenomenon that appeared only in this region. The research result is expected to be of some help in finding out various aspects of dialectal contacts as well as clarifying the phonological features of the local language in Yeongdong, and thereby contributing to exact divisioning of the Chungcheong dialect.

• 한국주조공학회지
• /
• 제29권6호
• /
• pp.270-276
• /
• 2009

After casting button-type small ingots of ternary Fe-Mn-S alloys which had three different Mn/S ratios (1, 5 and 70) in a vacuum arc furnace, the effect of the ratio on the sulfide formation was investigated. In case of the Mn/S ratio of 1, if alloy composition was located in an iron-rich corner on a Fe-Mn-S ternary phase diagram, only duplex MnS-FeS sulfide films were observed in the grain boundary. If the alloy composition was located in the miscibility gap area of the phase diagram, primary globular dendritic sulfides and dendritic sulfide slags were generated within the grain and tubular monotectic sulfides were also detected in the grain boundary. When the Mn/S ratio was 5, if the alloy composition was in the iron-rich corner, only bead-like sulfides were generated. On the other hand, if the composition was in the miscibility gap area, globular dendritic sulfides and dendritic sulfide slags were generated in the form of primary sulfide inclusions and rod-like eutectic sulfides were observed in the grain boundary. Especially, if the contents of Mn and S increased more in the miscibility gap area of the phase diagram, primary globular sulfides containing iron intrusions were observed. In case of Mn/S ratio of 70, if the contents of Mn and S was decreased in the Fe corner of the phase diagram, only bead-like sulfides were observed in the grain boundary. Despite the composition was outside the miscibility gap area of the phase diagram, if the contents of Mn and S increased, clusters of fine sulfide particles as well as fine spherical primary monophase sulfides were observed in the grain boundary.

• 지적과 국토정보
• /
• 제45권2호
• /
• pp.101-116
• /
• 2015

경계점좌표 등록지역에서 지적공부 세계측지계 변환의 정확도는 기준점 측량성과에 의해 결정된다. 하지만 현재 기준점 측량성과는 등록 당시 측량기술과 방식의 한계로 인해 불균질한 성과를 나타내고 있으며, 사업지구별 특성이나 형성 시기에 따라 다양한 오차를 가지고 있다. 따라서 본 연구에서는 경계점좌표 등록지역 사례에 대해 사업지구 유형별 오차 원인을 규명하고, 세계측지계 변환과 검증측량을 통해 최적의 측지계 변환방법과 정확도의 향상 방안을 제시하였다.

• 한국지리정보학회지
• /
• 제22권1호
• /
• pp.39-50
• /
• 2019

2012년부터 "지적재조사에 관한 특별법"이 시행됨에 따라 우리나라의 지적재조사사업이 본격적으로 추진되고 있으나 사업예산 확보의 어려움과 도심지역을 중심으로 필지면적 증감에 따른 토지경계 설정 및 조정금 산정, 사업 주체와 토지 소유자 또는 경계를 이웃한 토지소유자 등 이해당사자 간의 의견 대립의 문제가 발생하고 있다. 따라서 이 연구에서는 우리나라보다 앞서 지적재조사를 추진하고 있는 일본의 관민경계제도의 분석을 통해 지적재조사 사업에 있어 경계설정 등 합의사항 추진 시 복잡한 이해관계를 한번에 결정하려하지 말고 이해관계자 대상을 줄여 단계적으로 추진할 필요가 있다. 또한 관민경계 선행조사를 통한 지적재조사의 비용절감 방안도입이 필요함에 따라 MMS를 이용한 정밀도로지도 구축사업등과의 연계, 지적재조사를 위한 선행조사사업 등의 도입, 관민경계기본조사 정보의 중요도와 국토조사정보로의 활용적 가치를 고려하여 도시재생, 도시계획업무 등과 연계추진이라는 방향을 제시하였다.

• 대기
• /
• 제27권4호
• /
• pp.455-466
• /
• 2017

In Korea, property and human damages occur annually due to heavy precipitation during the summer. On August 8, 2015, heavy rainfall occurred in the Seoul metropolitan area due to an outflow boundary, and $77mmhr^{-1}$ rainfall was recorded in Gwangju, Gyeonggi Province. In this study, the simulation of the WRF numerical model is performed to understand the cause and characteristics of heavy rainfall using the Conditional Instability of the Second Kind (CISK), potential vorticity (PV), frontogenesis function, and convective available potential energy (CAPE) analyses, etc. Convective cells initiated over the Shandong Peninsula and located on the downwind side of an upper level trough. Large amounts of water vapor were supplied to the Shandong Peninsula along the southwestern edge of a high pressure system, and from the remnants of typhoon Soudelor. The mesoscale convective system (MCS) developed through CISK process and moved over to the Yellow Sea. The outflow boundary from the MCS progressed east and pushed cold pool eastward. The warm and humid air over the Korean Peninsula further enhanced convective development. As a result, a new MCS developed rapidly over land. Because of the latent heat release due to convection and precipitation, strong potential vorticity was generated in the lower atmosphere. The rapid development of MCS and the heavy rainfall occurred in an area where the CAPE value was greater than $1300Jkg^{-1}$ and the fronto-genesis function value of 1.5 or greater coincided. The analysis result shows that the MCS driven by an outflow boundary can be identified using CISK process.