• Title/Summary/Keyword: 김대식

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Seasonal Changes of Shorelines and Beaches on East Sea Coast, South Korea (동해안 해안선과 해빈의 계절적 변화)

  • Kim, Dae Sik;Lee, Gwang-Ryul
    • Journal of the Korean Geographical Society
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    • v.50 no.2
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    • pp.147-164
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    • 2015
  • This study analyzed characteristics and tendencies of seasonal change on shoreline and beach with 8 beaches at East Sea coast by topographical survey for 2 years from March 2012 to February 2013. The shorelines of East Sea coast appeared that amount of seasonal change was bigger than amount of annual change. The seasonal change tendencies between Gangwon-do and Gyeongsangbuk-do coast areas existed some regional differences. To synthesize seasonal changes on 8 beaches of East Sea coast, shoreline advance and beach deposit showed clearly in summer and shoreline retreat and beach erosion showed clearly in autumn. This result is different from tendencies of seasonal change in many mid-latitude coast areas of the world, but generally corresponds with reference studies in west coast and east coast. The major factor of beach erosion showing mostly in summer is storm wave caused by typhoon. The beach erosion by storm wave also occurred in late winter. And it assumes that the beach deposit showing mostly in autumn is result of equilibrium processes of coast area against strong erosion in summer.

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Analysis of Land Conversion Characteristics in Process of Farmland Loss and Urbanization by Distance from Center of City Using Detailed Digital Land Use - With Representative Big Cities and Their Fringe Areas in Japan - (정밀수치정보를 이용한 도시중심에서 거리별 농지손실 및 도시화과정의 토지전용 특성 분석 - 일본의 대표적 도시주변지역을 중심으로 -)

  • Kim, Dae-Sik
    • Journal of Korean Society of Rural Planning
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    • v.9 no.1 s.18
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    • pp.65-75
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    • 2003
  • As a pre-step research to make land-use planning in the region level, this study aims to analyze some probability pattern representing transition probabilities from farmland to others using the sequential detailed digital land-use maps. Kinki and Chubu regions of Japan, which have Osaka and Nagoya cities as their center places respectively, were selected as test regions in this study. The 10m grid land-use maps for four time series at every 5 year from 1977 to 1992 were used. In this study, the regions were divided into three sub-areas 10km, 20km, and 30km according to distance from center cities, respectively. The correlation coefficient (CC) between sub-areas with same distance in the two regions was calculated to analyze whether or not the two regions have common points in the pattern of land-use conversion probability from farmland to other types. The probability distribution of the converted areas which were moved to the urbanized area (residential, commercial, industrial, road, park and public facility areas) was about $40{\sim}70%$ for both all periods and sub-areas. According to distance from city centers, the probability moved to the urbanized area was about 60% at 10km area, and 40% at the 30km area, which means that the values we decreased gradually, while in the case moved to the forest and the etc areas, the values were increased slightly. The CC analysis from the paddy field and the dry field to the others separately showed that there is high correlation in the probability pattern between the two regions.

A Study on Application of Landscape Diagnosis Index and Landscape Formation Plan of Rural Villages (농촌마을단위 경관진단지표 적용 및 경관형성방안에 관한 연구 - 충청북도 9개 마을을 대상으로 -)

  • Song, Hee-Jung;Kim, Dae-Sik;Doh, Jae-Heung;Koo, Hee-Dong
    • Journal of Korean Society of Rural Planning
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    • v.19 no.4
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    • pp.149-160
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    • 2013
  • In this study, it propose what the landscape elements is to be improved urgently and how to improve landscape by reflecting the rural village characteristics away from the spatial integrated landscape planning. The study area for landscape research is selected as the 9 rural villages in Chungcheongbuk-do, and research is done by using village unit landscape diagnostic index(VULDI). the result is shown that average VULDI value of the rural village zones is bigger than one of the town village zones with difference of 15%. Two zones of Chilseong-myeon and Sangchon-myeon among the town village zones are appeared to be similar with the rural village zones in landscape level by VULDI value. Generally, the rural villages to maintain the good landscape have the low population and high engagement rate in agriculture. Looking political support criteria at the landscape level, the seven zones except Deoksan-myeon and Maengdong-myeon have high VULDI value more than 60%, which means that it seems unnecessary to support political landscape improvement. However, when it is divided into two parts of the village inside landscape and the surrounding landscape, 8 rural village zones except one zone of Sangchon-myeon have low VULDI value less than 60%, which means it is necessary to support political landscape improvement. It is important to give the intensive support of ever urgent landscape improvements and high priority landscape elements on the results of the diagnostic before planning of the rural landscape formation.

A Hierarchical Network Architecture and Handoff framework for Integrating CDMA2000, WiBro and WLAN (CDMA2000, WiBro 및 WLAN 연동을 위한 계층적 네트워크 구조와 핸드오프 프레임워크)

  • Kong, Du-Kyung;Cho, Jin-Sung;Kim, Seung-Hee;Kim, Dae-Sik
    • Journal of Internet Computing and Services
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    • v.7 no.5
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    • pp.43-57
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    • 2006
  • Next-generation mobile communication systems evolve in the form of high speed data transmission along with integration of wired-wireless network. Therefore, it needs researches on integrating service to heterogeneous networks to offer high speed data transmission and various services while supporting user mobility. In existing studies, heterogeneous networks are linked to single core network separatively, Since vertical handoff between heterogeneous networks leads to some delay, packets may be lost during vertical handoff. To solve this problem, this paper proposes an hierarchically integrated network architecture considering the characteristics of CDMA2000, WiBro, and WLAN. The hierarchically integrated networks are overlaid according to coverage of each network. Therefore, the proposed architecture can minimize handoff delay and packet loss. In addition, this paper proposes an integrated framework for next generation mobile communication networks.

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A Study on 3 Dimensional Modeling of Keum-man Connection Canal using GIS and considering Hydraulic Analysis (GIS와 수리학적 해석을 고려한 금만연결수로의 3차원 모델링에 관한 연구)

  • Kim, Dae-Sik;Nam, Sang-Woon;Kim, Tai-Cheol
    • Journal of The Korean Society of Agricultural Engineers
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    • v.50 no.5
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    • pp.3-15
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    • 2008
  • This study aims to simulate the 3 dimensional (3D) model of Keum-man connection canal using geographic information system (GIS) as well as considering design in viewpoint of engineering. The canal connects from Keumkang to Mangyungkang in order to supply fresh water into Saemankeum lake. This study used 3 dimensional spatial planning model (3DSPLAM) process to generate the 3D model, which has not only several planning layers in actual process, but also their corresponding layers in modeling process to simulate 3D space of rural villages. The discharge of the canal is $20m^3/s$ on slope of 1/28,400 in the canal length of 14.2km, which consists of pipe line and open channel. This study surveyed the route of the canal and its surrounding environment for facilities to make images in the 3D graphic model. Besides, the present study developed data set in GIS for geogrphical surface modeling as well as parameters in hydraulic analysis for water surface profile on the canal using HEC-RAS model. From the data set constructed, this study performed analysis of water surface profile with HEC-RAS, generation of digital elevation model (DEM) and 3D objects, design of the canal section and route on DEM in AutoCAD, and 3D canal model and its surrounding 3D space in 3DMAX with virtual reality. The study result showed that the process making 3D canal model tried in this study is very useful to generate computer graphic model with the designed canal on the surface of DEM. The generated 3D canal can be used to assist decision support for the canal policy.

Photodynamic Inactivation of Moraxella catarrhalis (Moraxella catarrhalis의 광역학적 비활성화)

  • Hong, Seong-No;Kwon, Pil-Seung;Kim, Dae-Sik
    • Korean Journal of Clinical Laboratory Science
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    • v.39 no.1
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    • pp.19-24
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    • 2007
  • The aim of this study was to evaluate the bacterial effects of Moraxella catarrhalis in otitis media with effusion (OME) by photodynamic therapy (PDT). Bacterial suspensions (10000 CFU/mL) were prepared. The colony forming units (CFU) of Moraxella catarrhalis have been measured after an application of photogem plus 632 nm diode laser irradiation. One ml of the bacterial suspensions have been incubated in the dark for 3h with various concentrations of photogem ($0.625{\sim}5.0_{\mu}g/mL$) and then irradiated with 632 nm diode laser ($15J/cm^2$). After, the PDT Moraxella catarrhalis suspensions ($50{\mu}L$) were inoculated on chocolate agar plate and cultured in the dark at $37^{\circ}C$, 5% $CO_2$ condition for 18h. The colony forming units off the bacteria were measured. Also transmission electron microscopy (TEM) was employed to evaluate the effect of otitis media pathogens by PDT. The nucleus of Moraxella catarrhalis was stained using green fluorescent nucleic acid dye thiazole orange and the fluorescence intensity of the nucleus was measured by flow cytometry. The PDT was effective in killing Moraxella catarrhalis at the photogem dose of $5.0_{\mu}g/mL$, respectively, As assessed by flow cytometry analysis the fluorescence intensity of the nucleus got lower after PDT. TEM result appeared to able to cause damage to the bacterial membranes. On the basis of these findings, bacterial photodynamic therapy with photogem can be considered to be a promising new therapeutic approach for OME.

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A Study of Administration of Cyber Range (사이버 레인지 운용 방안 연구)

  • Kim, Daesik;Kim, Yonghyun
    • Journal of Internet Computing and Services
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    • v.18 no.5
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    • pp.9-15
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    • 2017
  • In the whole world the Attack Technologies of cyber warfare in modern society are growing faster and complicated. The frequency of the new attacks is shorter than before day by day. The defense technologies and experts against these attacks are very few. One of answers to solve these problems is the cyber range as a test-bed to prepare the cyber warfare considered by many countries. This paper examines the foreign cases and similar systems, collects and analyzes various attributes for cyber range. Finally it refines them through system engineering processes. In these processes missions and concepts for administration are set with architecture framework. The logical architecture is designed. Based on designed architecture two goals, defense technologies and procurement of experts, are established. And it shows effective and persistent administration of cyber range.

Anti-inflammatory Effects of Pyropia yezoensis Extract in LPS-stimulated RAW 264.7 cells (방사무늬 김(Pyropia yezoensis) 추출물에 의한 RAW 264.7 대식세포의 항염증 효과)

  • Lee, Ji Young;Choi, Jeong Wook;Lee, Min Kyeong;Kim, Young Min;Kim, In Hye;Nam, Taek Jeong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.47 no.6
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    • pp.757-764
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    • 2014
  • Many researchers have studied algae as a source of material having potential biological activities, not least because many marine algae extracts have strong antioxidant properties. In this study, we investigated the anti-inflammatory effects of Pyropia yezoensis extract (PYE) on RAW 264.7 cells by measuring nitric oxide (NO), reactive oxygen species (ROS), superoxide dismutase (SOD), catalase activity, inducible NOS (iNOS), cyclooxygenase-2 (COX-2), nuclear factor-kappa B (NF-${\kappa}B$), interleukin-$1{\beta}$ (1L-$1{\beta}$), and tumor necrosis factor-alpha (TNF-${\alpha}$). PYE decreased the production of intracellular ROS dose-dependently and increased SOD and catalase activity in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. PYE significantly suppressed the production of NO and reduced the expression of iNOS, COX-2, and NF-${\kappa}B$. PYE treatment also inhibited the production of IL-$1{\beta}$ and TNF-${\alpha}$ significantly and reduced the phosphorylation of Akt and MAPK significantly in LPS-stimulated RAW 264.7 cells. These results suggest that PYE has potential anti-oxidant and anti-inflammatory activities.

Thermoacoustic Analysis Model for Combustion Instability Prediction - Part 2 : Nonlinear Instability Analysis (연소 불안정 예측을 위한 열음향 해석 모델 - Part 2 : 비선형 안정성 해석)

  • Kim, Daesik;Kim, Kyu Tae
    • Journal of the Korean Society of Propulsion Engineers
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    • v.16 no.6
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    • pp.41-47
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    • 2012
  • It is very important to predict the nonlinear behavior of combustion instability such as transition phenomena and limit cycle amplitude for fully understanding and controlling the instabilities. These nonlinear instability characteristics are highly dependent upon the flames' nonlinear dynamics in a gas turbine premixed combustor. In this study, nonlinear instability TA(Thermo-acoustic) models were introduced by applying the concept of flame describing function to the thermoacoustic analysis method. As a result of model development, for a given combustor length, the growth rate of instability was greatly affected by the change in amplitude, although the instability frequency was not. Further researches under various operating conditions and model validation on limit cycle amplitude are required.

Limit Cycle Amplitude Prediction Using Results of Flame Describing Function Modeling (화염묘사함수 모델링 결과를 이용한 한계 진폭 예측)

  • Kim, Jihwan;Kim, Jinah;Kim, Daesik
    • Journal of the Korean Society of Propulsion Engineers
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    • v.20 no.6
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    • pp.46-53
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    • 2016
  • It is required to predict a limit cycle amplitude controlled by system's nonlinear behavior as well as an eigen-frequency and initial growth rate of instabilities under the linear motions, in order to fully understand combustion instabilities in a lean premixed gas turbine combustor. Special focus of the current work is placed on the limit cycle amplitude prediction using flame describing function(FDF) where the ratio of a heat release fluctuation to a given flow perturbation is expressed as a function of frequency and amplitude. In this study, the CFD modeling work based on RANS is carried out to obtain FDF, which makes that the nonlinear thermo-acoustic model is successfully developed for predicting the limit cycle amplitude of the combustion instability.