• 한국CDE학회논문집
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• 제10권6호
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• pp.432-443
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• 2005

Recent three-dimensional feature-based CAD systems based on solid or non-manifold modelling functionality have been widely used for product design in manufacturing companies. When product models associated with features are used in various downstream applications such as analysis, however, simplified and abstracted models at various levels of detail (LODs) are frequently more desirable and useful than the full detailed model. To provide multi-resolution models, the features need to be rearranged according to a criterion that measures the significance of the feature. However, if the features are rearranged, the resulting shape is possibly different from the original because union and subtraction Boolean operations are not commutative. To solve this problem, in this paper, the new concept of the effective zone of a feature is defined and identified using Boolean algebra. By introducing the effective zone, an arbitrary rearrangement of features becomes possible and arbitrary LOD criteria may be selected to suit various applications. Besides, because the effective zone of a feature is independent of the data structure of the model, the multi-resolution modelling algorithm based on the effective zone can be implemented on any 3D CAD system based on conventional solid representations as well as non-manifold topological (NMT) representations.

• 대한전기학회논문지:전력기술부문A
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• 제53권3호
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• pp.161-167
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• 2004

Zone 3 of the distance relay is used to provide the remote back-up protection in case of the failure of the primary protection. However, the risk lot mal-operations under stressed conditions such as heavy loading, voltage and transient instability is usually high. Zone 3 is used in combination with the derivatives of the voltage, and current, etc to prevent mal-operations. Sometimes, the impedance characteristics that restrict the tripping area of relay are used to avoid the mal-operations due to load encroachment. This paper presents a novel Zone 3 scheme based on combining the steady-state components (i.e. 60Hz) and the transient components (TCs) using a state diagram that visualizes the sequence of studies that emanate from the sequence of events. The simulation results show that the novel zone 3 distance relay elements using the proposed method operates correctly for the various events.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.643-650
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• 2002

It is necessary, in the light of the importance of long-term slope stability problem, to develop a simple method or tool which can figure out the possible failure zone resulted from weathering effect and other factors. The FBG sensor system is used to estimate the correlations between the temperature and the slope in Yunhwajae, and to find a failure zone in slopes effectively. This research is to seek for the correlation between the soil temperature distribution and the strain distribution in a active zone by analyzing the data from the in-situ measurement so that the possible failure zone should be well defined based on the correlation. The zone of high temperature fluctuation can be regarded as one of the possible sliding zone due to the weathering effect while the constant temperature depth of the ground, if exists, would not be relatively affected by the weathering process.

• The Korean Journal of Ecology
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• 제15권1호
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• pp.59-65
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• 1992

Pollen analysis to clear vegetational history of korea was carried out on the deposite taken from the pit of the miruksa site, south-western korea(36o00'18'N, 127o1'12'E, 10m in alt.). This area has been known as the cool temperate zone(southern zone) according to yim and kira(1975). But, now we can not found the original vegetation because the area has been disturbed severely and almost area changed to cultivated land.the area is one of the most developd area in early agricultural stage of korea. By the pollen diagram, three local pollen zones are distinguished in this site, bottom to surface, as following. is-Ⅰ :pinus-quercus zone (140∼120 cm, sample 1 and 2) is-Ⅱ :ulmus+zelkova zone(120∼84 cm, sample 3∼6) is-Ⅲ :pinus zone(84∼0 cm, sample 7 ∼13) is-Ⅰ is characterized by high values in frequences of pinus, the temperate conifer and quercus the cool temperate oak, and is-Ⅱ zone by the decrease of quercus and increase of ulmus and increase of ulman+zelkova as ravine forest elements, isⅢ zone is characterized by pinus, especially, based on data of sample no.9.

• Journal of Ecology and Environment
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• 제37권4호
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• pp.185-194
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• 2014

Seasonal monitoring was implemented to understand the influence of macrophyte bed structure on the composition and trophic interaction of aquatic organisms (algae, zooplankton, macro-invertebrate, and fish) in a shallow wetland (Upo Wetland, South Korea). Distinct division of the plant assemblage (reed zone and mixed plant zone) was observed. The reed zone was composed solely of Phragmites communis, whereas the mixed plant zone comprised a diverse macrophyte assemblage (Salvinia natans, Spirodela polyrhiza, Trapa japonica, Ceratophyllum demersum, and Hydrilla verticillata). Most of the aquatic organisms were more abundant in the mixed plant zone than in the reed zone, and this was positively associated with the seasonal development of macrophyte cover. Stable isotope analysis showed seasonal interactions among aquatic organisms. The majority of aquatic animal (zooplankton, Odonata, and Ephemeroptera) were dependent on epiphytic particulate organic matter (EPOM), and the dependence on EPOM gradually increased toward autumn. Interestingly, Lepomis macrochirus consumed Ephemeroptera and zooplankton in both macrophyte zones, but Micropterus salmoides depended on different food items in the reed zone and the mixed plant zone. Although, M. salmoides in the reed zone showed food utilization similar to L. macrochirus, it consumed Odonata or small L. macrochirus in the mixed plant zone. Based on these results, it appears that differences in the structure of the two macrophyte zones support different assemblages of aquatic organisms, strongly influencing the trophic interactions between the aquatic organisms.

• 생물환경조절학회지
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• 제15권4호
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• pp.340-345
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• 2006

A potato (Solanum tuberosum L. cv. Superior) cultivar was grown in aeroponic cultivation system to investigate the effect of root zone cooling in summer. Based on their nutrient uptake, growth responses, and tuberization, the possibilities for potato seed production were determined. Although shoot growth and early tuberization increased in the conventional non-cooling root zone system (root zone temperature of $25\pm2^{\circ}C$), stolen growth, photosynthesis, transpiration rate and number of tubers produced were higher in the cooling root zone system ($20\pm2^{\circ}C$) than in the non-cooling system. Increasing root zone temperature above $25^{\circ}C$ stimulated absorption of K more than T-N, P, Ca, Fe and Mn. On the other hand, root zone temperatures in the range of $20^{\circ}C$ to $25^{\circ}C$ did not affect Mg contents. The lower uptake and supply to leaves of T-N, Fe and Mn at the high root zone temperature promoted early tuberization and advanced haulm senescence. The results stress the importance of keeping root zone temperature to as low as below 20, particularly in summer under temperate Bone.

• 한국분말재료학회지
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• 제25권4호
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• pp.331-335
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• 2018

This study investigates the directional recrystallization behavior of Ni based oxide dispersion strengthened (ODS) alloy according to the zone annealing velocity. The zone annealing temperature is set as $1390^{\circ}C$, while the zone velocities are set as 2.5, 4, 6, and 10 cm/h, respectively. The initial microstructure observation of the as-extruded sample shows equiaxed grains of random orientation, with an average grain size of 530 nm. On the other hand, the zone annealed samples show a large deviation in grain size depending on the zone velocities. In particular, grains with a size of several millimeters are observed at 2.5-cm/h zone velocity. It is also found that the preferred orientation varies with the zone annealing velocity. On the basis of these results, this study discusses the role of zone velocities in the directional recrystallization of Ni base ODS alloy.

• 한국도로학회논문집
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• 제17권6호
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• pp.117-126
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• 2015

PURPOSES : This study prioritizes potential technology for establishing a safe work zone environment on roadways. We consider almost all conceivable technologies that enable mitigation of unexpected accidents for both road workers and drivers. METHODS : This study suggests a methodology to set the priority of potential technology for establishing a safe work zone environment by using the analytical hierarchy process (AHP). For this purpose, the AHP structure was first developed. Thereafter, a web-based survey was conducted to collect experts' opinions. Based on the survey results, weights associated with the relevant criteria of the developed structure were estimated. With the consistency index (CI) and consistency ratio (CR), we verified the estimated weights. In addition, a sensitivity analysis was performed to confirm whether the estimated weights were reliable. We finally proposed the priority for potential technology for establishing a safe work zone environment on roadways. RESULTS : In the first level, safety technology has the highest priority, and real-time information delivery for work zone, hazard warning for drivers, and temporal automated operation for traffic facilities were selected in the second level of hierarchy. CONCLUSIONS : The results imply that establishing the priority will be useful to establish a future road map for improving the work environment for road workers and drivers by employing appropriate protection facilities and developing safety systems.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 춘계학술대회
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• pp.273-276
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• 2011

본 논문에서는 Cloud 서비스를 지원하기 위하여 유닉스 가상화 시스템을 구현하고, 자바기반의 애플리케이션을 사용한 서비스 방식을 제안한다. 유닉스 가상화는 Web Server zone 과 NFS zone, FTP zone의 세가지 시스템으로 나누어 구현하며. 애플리케이션은 자바 프로그래밍으로 구현하게 된다. 애플리케이션과 유닉스 시스템을 연동함으로서 언제 어디서나 데이터 업로드 다운로드, 음악 감상, 문서 작업 등 효율성을 제공할 수 있도록 한다. 유닉스 가상화에 따라서 서버자원의 에너지 절감을 기대할 수 있고, PC없이 스마트 폰으로 업무를 처리 할 수 있게 되는 효과를 얻게 된다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.612-613
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• 2016

오늘날 여성이나 어린이를 보호하기 위한 다양한 시스템들이 개발되고 있다. 그러나 여전히 그린 존 내의 범죄율이 상승하고 있으며 이를 보호하기 위한 시스템의 필요성이 부각되고 있다. 본 논문에서는 등록된 범죄자가 그린존 지역에 접근 시 그린존 관리자에게 실시간으로 메시지를 전달하는 시스템을 제안한다. 이는 기존 시스템이 모니터링을 통해 수동적으로 데이터를 전송하는 것과 달리 제안하는 시스템은 설정된 그린존 접근 시 이를 GPS 기반으로 감지한다. 이에 따라 등록된 대상을 실시간으로 감시하고 관리할 수 있어 범죄자들로부터 여성과 어린이를 보호할 수 있을 것으로 판단된다.