• Archives of design research
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• v.13 no.2
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• pp.95-102
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• 2000

The purpose of this study is to find out what is the preference of users according to the location of benches at urban community parks. This location of benches is seperated into 4 patterns according to arranging pattern of water space, a walk, pergola and shelter, greenspace. To investigate the visual preference is examined by analyzing visual volume of 4 patterns. Results are as follows; 1. Factor analysis by the total data showed that 5 factors explain 60.40 percent of total variance of the location of bench visual character. They were classified by the sensitive factor, visual factor, physical-individual factor, distinct factor, density factor. Among 5 factors, the sensitive factor which represented psychological reaction was appreciated to be highest. 2. Most of 20 items showed the following scores of mean values in sementic differential experiment : Spot 1->Spot 4-> 2-> 3. The mean values between arrangement place locational differences showed significantly, that could explain to be a violent contrast between the natural factors(weater space, green space, etc) and the artificial factors (around of pergola, shelter, etc)

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.6
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• pp.71-79
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• 2016

Evaluation of the walkability of the urban pedestrian network requires construction of a pedestrian network model that reflects Space Syntax Theory. Space Syntax Theory deduces an integration value through which materials for evaluation of the pedestrian network's connectivity can be produced; and can aid in illustrating the ease of walkability through the model's calculation of pedestrian indices such as movability, comfort, and safety. But the representation of space syntax theory in the pedestrian network requires that turn delay be added by means of a network-type construction method. While tree-based Dial Algorithm proposed for the logit-based probability walkability distribution model may be effective for link-based pedestrian volume distribution, it requires further network expansion to reflect turn delays. In this research, Vine-based Dial Algorithm is executed in order to obtain a measure reflecting the integration value for Space Syntax Theory. The Vine-based Dial Algorithm of two adjacent links, which forms the minimum unit of the Vine network, has the advantage of encompassing turn delay, and thus eliminates the need for network expansion. Usage of the model to evaluation of complicated pedestrian spheres such as urban roads is left to further research. Especially the progression of the proposed method is deduced through case study.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.4
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• pp.247-252
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• 2013

Pit and fissure sealant prevents biofilm accumulation, plays a role in forming a barrier to acidic substance made by the bacteria. The Surface reaction-type pre-reacted glass ionomerI(S-PRG) filler was developed in 1999. S-PRG filler releases fluoride continuously and does not decompose under wet conditions. The aim of this study was to test the microleakage and anticariogenic effect to adjacent enamel of S-PRG filler-containing pit and fissure sealant. Sound premolars and molars were used in this study. A S-PRG filler-containing pit and fissure sealant, Beautisealant$^{(R)}$(Shofu, Japan) was used for this experiment, the composite resin sealant Concise$^{(R)}$(3M ESPE, USA) was used as control. For the microleakage test, all teeth surface were double coated with finger nail varnish, with the exception of a 1.0 mm window around the restoration margins. The teeth were immersed in 2% methylene blue solution for 24 hours and then rinsed in tap water. For the anticariogenic effect evaluation, all tooth were immersed in artificial carious solution for 9 days and rinsed with tap water. Each tooth was embedded in orthodontic acrylic rein and subsequently sectioned longitudinally in a bucco-lingual direction with a low-speed diamond saw. The cut sections were examined using a stereomicroscope. Differences in microleakage between the two groups were not different significantly. But the S-PRG filler-containing pit and fissure sealant showed higher anticariogenic effect than that of flowable resin sealant.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.7
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• pp.898-906
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• 2018

To investigate the effect of yellow dust on phytoplankton, a field survey and physiological experiments were carried out in the waters near Taean Peninsula from April 22 to 26, 2006, when yellow dust occurred. Phytoplankton populations during the yellow dust period were in the range of $26{\sim}290{\times}10^3cells{\cdot}L^{-1}$, a somewhat low standing crop. An increase in diatoms (a main taxonomic group), especially benthic diatoms such as Paralia sulcate, a typical species for active mixed sea water areas, was also remarkable. In addition, the Chl-a concentration after yellow dust exceeded the Chl-a concentration change range according to the tide before yellow dust. As the concentration of yellow sand increased in a yellow sand treatment experiment, primary productivity decreased, and the maximum assimilation number showed the same tendency. In the 48h culture experiment, primary productivity of the test group was lower than that of the control group at the early stage (T0) of yellow sand treatment, but after 48 hours (T48), the test group showed higher primary productivity than the control group. In particular, the primary productivity of the test group significantly increased to 321 % after 48 hours. Therefore, strong physical environment accompanied by yellow dust may temporarily inhibit the growth of phytoplankton in the waters adjacent to China in the early stage of yellow dust, but the formation of stable water mass has also been identified as a potential factor promoting the growth of phytoplankton.

• Proceedings of the KOR-KST Conference
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• 1998.10a
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• pp.151-160
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• 1998

실시간 교통정보 처리과정은 현장설비로부터 수집되는 각종 교통상황자료를 분석/처리하여 소통상황, 주행속도, 통행시간 등의 교통상황을 단기 예측하는 과정으로서 이는 주행안내시스템의 핵심요소기술이다. 주행안내 시스템 개발의 필요성은 선진국을 중심으로 제기되어 왔으며, 주행안내시스템은 각국 정부의 강력한 지원정책을 바탕으로 연구개발 단계를 거쳐 시범운영의 단계에 있다. 국내에서도 교통정체의 해소와 안전주행의 연구개발 단계를 거쳐 시범운영의 단계에 있다. 국내에서도 교통정체의 해소와 안전주행의 여건마련을 위하여 교통정보를·처리·제공하는 기술의 개발이 활발하게 진행되고 있다. 그러나 국내 기술수준을 보면 전자통신기술을 바탕으로 교통정보의 수집과 제공에 관한 연구는 어느 정도 진행되고 있으나 운전자가 필요로 하는 교통정보의 분석과 처리에 관한 연구는 매우 저조한 실정이다. 본 연구의 목적은 다양한 시스템에서 수집되는 자료를 종합적으로 처리, 저장,관리하고 이의 분석결과를 제공하는 교통정보센터의 프로토타입(Prototype)을 설정하는 것이다. 이러한 목표를 수행하기 위해서 요구되는 교통정보실험실의 기능은 수집된 교통자료의 신뢰성 분석, 교통정보의 종합적인 처리·저장·관리, 그리고 교통정보의 제공은 구분할 수 있다. 따라서, 현재 교통정보실험실에서 운영중인 정보의 형태를 제시하며, 이들 정보의 신뢰성을 실측자료와 비교한 실험적 결과를 예시한다. 또한, 개별 정보이용자에게 실시간 교통정보를 제공하기 위한 통신기술의 검토가 이루어진다. 차내 이용자에게 정보를 실시간으로 제공하기 위해서는 궁극적으로 무선통신기술의 응용이 필요하며, 정보이용자에게 다양한 정보를 제공하기 위해서 인터넷 통신과 연계시키는 것이 합리적으로 판단된다. 결론 부분에서는 교통정보실험실의 기능을 강화시키기 위한 향후의 연구과제를 제시한다.Si결정의 크기를 비교하였을 때 45$\mu\textrm{m}$ 이하의 분말을 섞어 압출하였을 때 가장 작은 초정 Si입자 크기를 얻음 을 볼 수 있었다. 주의 Fairfax County에 소재한 주간 고속도로 66번(I-66)과 인접 교통망의 교통자료를 사용하여 각종 돌발교통 혼잡 상황을 전제로 한 Traffic Simulation과 정보제공시나\리오를 INTEGRATION Model을 이용해 실행하였다. 그 결과 적응형 알고리즘이 개개인의 최단시간 경로를 제공하는 사용자 평형 경로안내전략에 비해 교통혼잡도와 정체시간의 체류정도에 따라 3%에서 10%까지 전체통행시간을 절약할 수 있다는 결론을 얻었다.출발참, 구성대외개방선면축심, 실현국제항선적함접화국내항반적전항, 형성다축심복사식항선망; 가강기장건설, 개피포동제이국제기장건설, 괄응포동개발경제발전적수요. 부화개시일은 각 5월 26일과 5월 22일이었다. 11. 6월 중순에 애벌레를 대상으로 처리한 Phenthoate EC가 96.38%의 방제가로 약효가 가장 우수하였고 3월중순 및 4월중순 월동후 암컷을 대상으로 처리한 Machine oil, Phenthoate EC 및 Trichlorfon WP는 비교적 약효가 낮았다.>$^{\circ}$E/$\leq$30$^{\circ}$NW 단열군이 연구지역 내에서 지하수 유동성이 가장 높은 단열군으로 추정된다. 이러한 사실은 3개 시추공을 대상으로 실시한 시추공 내 물리검층과 정압주입시험에서도 확인된다.. It was resulted from increase of weight of single cocoon. "Manta"2.5ppm produced 22.2kg of cocoon. It is equal to 9% increase in index, as com

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1639-1643
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• 2008

국내에서의 범람홍수 및 범람으로 인한 제방붕괴 특성은 그 해석상의 어려움으로 인해 주로 과거 범람상황 및 지형도를 통한 경험적 추정 등에 의존해 오고 있는 실정으로 정교한 물리학적 이론에 근거하지 못하였으므로 범람홍수량, 제방의 붕괴폭 등을 정확하게 예측하기에는 미흡한 점이 많았다. 도시하천과 같이 제방 인접한 곳에 주거, 산업시설 등이 밀집하고 있는 지역에서의 제방붕괴로 인한 홍수류의 범람은 막대한 인명 및 재산피해를 발생시키는 큰 재해가 될 수 있다. 본 연구를 통해서 홍수시 제방월류로 인한 제방붕괴 양상을 예측하고 이를 통해 범람유량의 정확한 예측을 통하여 도시하천 제방 계획시 홍수피해와 투자액을 감안한 경제적인 하천 제방단면 결정을 위한 기본자료로 활용될 수 있고, 도시 중요시설물의 입지 선정시 홍수피해에 대한 판단자료로 이용될 수 있을 것이다. 본 연구에서 개발된 모형을 이용하여 Teton 댐, Mantaro landslide 댐, Spirit Lake 장애물 댐 등에 적용하여 개발된 모형의 정확성을 입증하였다. 적용결과 개발된 모형은 기존의 모형과 같은 결과를 나타내어 국내 계산환경에 적용가능함을 보여 앞으로 이용가능성이 큰것을 알 수 있었다. 적용결과 파이핑의 발생위치의 영향은 대체로 파이핑의 위치가 제체의 윗부분에 위치할수록 최대 유출량은 커지는 것으로 나타났으나 Lawn Lake 댐의 경우에는 사면의 식생의 영향으로 다른 결과를 나타내었다. 점착력은 경우에는 점착력이 클수록 유출량의 크기는 감소하는 것으로 나타났으며 마찰각은 최대 붕괴폭의 크기 및 발생시간, 댐의 높이와 폭, 저수용량 등과 유출량이 연관있어 좀 더 많은 계산결과를 이용하여 심도있는 고찰이 요구되었다. 입자의 중간크기, 공극률, 균일성의 경우 적용된 댐들 모두 유사한 결과를 나타내었고 변수들이 커질수록 유출량도 증가하였다. 댐 사면 경사의 경우에는 상,하류 사면 모두 경사가 완만할수록 유출량이 감소하였다. 위의 결과를 통해 개발된 제방붕괴 해석모형은 좀 더 많은 연구와 적용을 통해 개선과 검증이 이루어진다면 국내 제방붕괴해석에 필요한 해석모형이 될 수 있다고 판단되었다.

• The Journal of Engineering Geology
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• v.26 no.1
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• pp.79-85
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• 2016

A concrete silo plays an important role in subsurface low- and intermediate-level waste facilities (LILW) by limiting the release of radionuclides from the silo geosphere. However, due to several physical and chemical processes the performance of the concrete structure decreases over time and consequently the concrete loses its effectiveness as a barrier against groundwater inflow and the release of radionuclides. Although a number of processes are responsible for degradation of the silo concrete, it is determined that the main cause is corrosion of the reinforcing steel. Therefore, the time it takes for the silo concrete to fail is calculated based on two factors: the initiation time of corrosion, defined as the time it takes for chloride ions to penetrate through the concrete cover, and the propagation time of corrosion. This paper aims to estimate the time taken for concrete to fail in a LILW disposal facility. Based on the United States Department of Energy (DOE) approach, which indicates that concrete fails completely once 50% of the volume of the reinforcing steel corrodes, the corrosion propagation time is calculated to be 640 years, which is the time it takes for corrosion to penetrate 0.640 cm into the reinforcing steel. In addition to the corrosion propagation time, a diffusion equation is used to calculate the initiation time of corrosion, yielding a time of 1284 years, which post-dates the closure time of the LILW disposal facility if we also consider the 640 years of corrosion propagation. The electrochemical conditions of the passive rebar surface were modified using an acceleration method. This is a useful approach because it can reduce the test time significantly by accelerating the transport of chlorides. Using instrumental analysis, the physicochemical properties of corrosion products were determined, thereby confirming that corrosion occurred, although we did not observe significant cracks in, or expansion of, the concrete. These results are consistent with those of Smartet al., 2006 who reported that corrosion products are easily compressed, meaning that cracks cannot be discerned by eye. Therefore, it is worth noting that rebar corrosion does not strongly influence the hydraulic conductivity of the concrete.

• Korean Journal of Ichthyology
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• v.19 no.3
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• pp.225-235
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• 2007

The freshwater fish fauna and physical characteristics of streams in Yeosu peninsula and Geumo Islands were surveyed at thirty nine stations in the period of 2003 and 2005. Most of the streams were short in length and narrow in flowing water width. Main materials of riverbed in most stations were cobble, pebble and gravel; those in the stations adjacent river mouth gravel and sand. In the river type, eighteen stations out of surveyed stations were upstream type: Aa. Thirty nine fish species belonging sixteen families were caught in this survey region. Among them twenty seven species were primary freshwater fishes and nine were peripheral. In the species composition of each family, there were the most species in Cyprinidae and Gobiidae, twelve and ten species, respectively. Endemic species of Korean peninsula in this region were eight species. One exotic fish species, Lepomis macrochirus was found in Yeosu peninsula. Dominant species in each district was Zacco temminckii in Yeosu peninsula, Rhinogobius brunneus in Dolsan Island, Leucopsarion petersii in Geumo island and Oryzias latipes in Gae island. In the analysis of community structure, it was appeared that the community of Yeosu peninsula was the most diverse and stable in this region; as the size of island became smaller, diversity and richness of community decreased. Kichulchoia brevifasciata did not caught in this survey, and it is possible that the species was extincted in this island. Acanthorhodeus gracilis and L. petersii were reported firstly in this region.

• The Journal of the Acoustical Society of Korea
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• v.27 no.7
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• pp.333-341
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• 2008

In this paper, a new interpolation model for the head related transfer function (HRTF) was proposed. In the method herein, we assume that the impulse response of the HRTF for each azimuth angle is given by linear interpolation of the time-delayed neighboring impulse responses of HRTFs. The time delay of the HRTF for each azimuth angle is given by sum of the sound wave propagation time from the ears to the sound source, which can be estimated by using azimuth angle, the physical shape of the underlying head and the distance between the head and sound source, and the refinement time yielding the minimum mean square error. Moreover, in the proposed model, the interpolation intervals were not fixed but varied, which were determined by minimizing the total number of HRTFs while the synthesized signals have no perceptual difference from the original signals in terms of sound location. To validate the usefulness of the proposed interpolation model, the proposed model was applied to the several HRTFs that were obtained from one dummy-head and three human heads. We used the HRTFs that have 5 degree azimuth angle resolution at 0 degree elevation (horizontal plane). The experimental results showed that using only $30\sim40%$ of the original HRTFs were sufficient for producing the signals that have no audible differences from the original ones in terms of sound location.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.4
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• pp.64-74
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• 2010

The study is based on an urban park design that is designed in consideration of the characteristics of Uijeongbu City, applied with adequate functions for the environment and showcasing the unique scenery in relation to the relocation of the US Air Force Camp Falling Water. The bases of the design are: the reasonable convergence of the square and park in consideration of the site characteristics; the application of an urban context as the park is located near a station; and the realization of an eco-friendly space. This study is based on foundation research regarding a review of urban square patterns, particular items in planning in relation to modern urban parks and the adaptability of the park in the future. Regarding space usage, the design is applied with notable ideas that allow the space to make its own characteristics through voluntary user activity in conjunction with the environment that will allow the park to cope with changes in the future, as opposed to a space that users experience through pre-determined programs. Below are the focal points of the design. First, the park is designed as an empty space which may accommodate the urban structural context of and usage patterns for being a field of the city ecology that changes and develops, beyond a passively-created square pattern. Such open spaces have a continuity which allows it to adapt to the development of the city. In addition, the design facilitates spontaneous processes through changes in usage pattern and time. Second, the design includes the message that the park and the city, natural things and artificial things, must communicate and network with each other. Hence the park shall not be an isolated green island within the city, but is an open space accommodating the demands for open area from nearby commercial, public and residential facilities; the park shall include a field that can accommodate a variety of programs. Third, the park is designed to encourage the effect of direct and indirect practical education by reflecting a physical plan as well as interesting experience design methods to lower carbon emissions and to create and maintain an eco-friendly space, the basis of a zero-emissions city.