• Journal of the Korean association of regional geographers
• /
• v.3 no.2
• /
• pp.105-120
• /
• 1997

One of the most important issues of object-oriented geographical database system is to develop an indexing technique which enables more efficient I/O processing within aggregation hierarchy or inheritance hierarchy. Up to present, several indexing schemes have been developed for this purpose. However, they have separately focused on aggregation hierarchy or inheritance hierarchy of object-oriented data model. A recent research is proposing a nested-inherited index which combines these two hierarchies simultaneously. However, this new index has some weak points. It has high storage costs related to its use of auxiliary index. Also, it cannot clearly represent the inheritance relationship among classes within its index structure. To solve these problems, this thesis proposes a pointer-chain index. Using pointer chain directory, this index composes a hierarchy-typed chain to show the hierarchical relationship among classes within inheritance hierarchy. By doing these, it could fetch the OID list of objects to be retrieved more easily than before. In addition, the pointer chain directory structure could accurately recognize target cases and subclasses and deal with "select-all" typed query without collection of schema semantic information. Also, it could avoid the redundant data storing, which usually happens in the process of using auxiliary index. This study evaluates the performance of pointer chain indexing technique by way of simulation method to compare nested-inherited index. According to this simulation, the pointer chain index is proved to be more efficient with regard to storage cost than nested-inherited index. Especially in terms of retrieval operation, it shows efficient performance to that of nested-inherited index.

• Journal of Korean Society for Geospatial Information Science
• /
• v.17 no.4
• /
• pp.53-60
• /
• 2009

Recently, the Korean government has amended the "National Territory Planning Act" by adding criteria to designate the Impact Fee Zone on the basis of the population increase rate. Taking the Dongtan Newtown in Hwasung City as the case, the study first tries to apply a grid analysis method to figure out the cells that exceed the legal population increase rate criteria. Then, the study, for rather a practical purpose, introduces a scenario analysis that tries to envelope the cells into a spatially contiguous groups based on their degrees of stepwise adjacency by cell buffer formation. By overlapping the selected cell groups chosen by such stepwise scenarios over the actual zoning map of land-uses for the vicinity, it seems clear that the chosen areas rationally coincide with those residential blocks and commercial areas with the high population density in the Newtown.

• Journal of Korean Society for Geospatial Information Science
• /
• v.18 no.4
• /
• pp.51-60
• /
• 2010

In 2008, the Development Impact Fee Zoning has been newly amended and added to the existing National Territory Planning Act. Since the beginning of 2009, many local governments nationwide started to adopt the law as a powerful tool to prepare the prescirbed masterplans for the installment of adequate infrastructure and to procure the financial resources to realize the plan. The study, in this context, tried to build gridded population data and analyzed the population cells that exceed the legal criteria of population increase rate required by the law over the case area of Sooyoung-Ri in Hwasung City. The study further probed to group the selected population cells in five specified increasing steps on which the alternative impact fee zones are built. Throughout the process, the study could properly set a reasonable impact fee zone and suggested a practical examples of the final zone specification applicable by the localities.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.12 no.4
• /
• pp.74-83
• /
• 2009

In September 2008, the Korean government has legally pronounced criteria to designate the Impact Fee Zone on the basis of the population increase rate. Taking the Dongtan Newtown in Hwasung City as the case, the study tries a grid analysis method to figure out the cells that exceed the legal population increase rate criteria. The study then performs scenario analyses that try to envelope the cells into spatially contiguous groups based on their degrees of stepwise adjacency either by the cell buffer or the cell distance standards. By overlapping the selected cell groups over the actual land-use map for the vicinity, it is found that the selected areas reasonably coincide with the blocks of the high population density in the Newtown.

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.34 no.10
• /
• pp.131-142
• /
• 2018

Being dealt in Alfred Weber's Theory of the location of Industries, a lot of economic benefits can be obtained through aggregation and clustering of industrial facilities, which derived to the development of industrial complexes in Korea. However, with the IMF economic crisis as well as various institutional changes, the framework of aggregation and clustering of industries is broken, which led to individual developments that took place without any consideration of surrounding industries. For reformation of these condition of industrial complexes, national government-led regeneration projects are being carried out currently. However, national government-led projects mainly focus on profitable projects such as officetel and hotel that are irrelevant to exist composition of industrial complexes which is usually manufacturing base industries and are unable to solve the fundamental problems of industrial complexes. Thus, a necessity of industry clustering is deduced through case analysis of actual private-led manufacturing industry cluster with governance and analysis of benefits on financial, spatial and environmental aspects. In addition, implications on the necessity follow base on factorial analysis on the benefit of clustering development than individual development as well as analysis on the measures taken for successful clustering.

• Nuclear Engineering and Technology
• /
• v.25 no.2
• /
• pp.193-203
• /
• 1993

A new heuristic method for loading pattern search has been developed to overcome short-comings of the algorithmic approach. To reduce the size of vast solution space, general shuffling rules, a regionwise shuffling method, and a pattern grouping method were introduced. The entropy theory was applied to classify possible loading patterns into groups with similarity between them. The pattern search program was implemented with use of the PROLOG language. A two-group nodal code MEDIUM-2D was used for analysis of power distribution in the core. The above mentioned methodology has been tested to show effectiveness in reducing of solution space down to a few hundred pattern groups. Burnable poison rods were then arranged in each pattern group in accordance with burnable poison distribution rules, which led to further reduction of the solution space to several scores of acceptable pattern groups. The method of maximizing cycle length(MCL) and minimizing power-peaking factor(MPF) were applied to search for specific useful loading patterns from the acceptable pattern groups. Thus, several specific loading patterns that have low power-peaking factor and large cycle length were successfully searched from the selected pattern groups.

• Journal of Korean Society of Transportation
• /
• v.11 no.1
• /
• pp.37-54
• /
• 1993

본 연구는 화물수송수단 선택 모형이론과 그 적용측면을 개괄적으로 살펴봄으로써 관련 현황수준(state of the art)에 대한 이해를 높이고, 발전방향을 모색함에 그 목적이 있다. 이러한 관점에서 먼저, 모형구성 정황(context)과 집단화(aggregation)를 포함한 화물수송수요 모형화의 몇가지 기본과제를 고찰한다. 이어서 집단모형과 비연속선택 개별모형으로 대별되는 모형이론과 그 세부적 구조(specification)를 설명하고 각 모형들의 중요성(significance)에 관하여 언급하며, 비연속선택모형의 추정과 관련된 기존의 투입자료형태 및 표본추출방법들에 대하여 문헌조사를 통하여 고찰함으로써 그 장단점과 중요성을 검증한다. 마지막으로 이러한 논의 및 검토결과를 토대로 화물수송수요예측을 위한 앞으로의 연구방향을 제시하여 본다.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2004.05a
• /
• pp.632-635
• /
• 2004

PCB assembly is a complicated and difficult process to optimize due to the necessity of simultaneous consideration of rack assignment and board mounting sequencing. An efficient component mounting method is developed using component gathering phenomenon. It is found that same components are located closely each other by checking PCBs in field and interviewing PCB designers. A new method counting this phenomenon is developed and it is performed better with more number of total components and more number of gathered components cases. Simulation models are developed using Visual C++ for performance evaluation of the heuristic.

• Journal of computational fluids engineering
• /
• v.21 no.4
• /
• pp.46-53
• /
• 2016

Direct numerical simulation is conducted to observe the behavior of microbubbles in isotropic turbulence. Navier-Stokes equation and the motion of equation for microbubbles are solved with periodic boundary condition in a cube domain. Vorticity contour, enstrophy ratio, relative reduction of bubble rise velocity, and the closest distance of particles are investigated for various Stokes numbers and gravity factors to understand clustering of microbubbles. Also, clustering due to the effect of the lift force is investigated.

• Proceedings of the Korea Contents Association Conference
• /
• 2003.11a
• /
• pp.60-64
• /
• 2003

Individualization serverces to be persuited in most web sites are not one automated by system but collectivization services provided into several groups with information collected in initial register. Also, as most of the web sites provide individualization services according to environmental setting fitted by each individual, it is hard to offer to provide them with analyzing members by system itself. In this paper, as we store behavior characters of members on web surfing into member database and anlyze them automatically, system itself enables to provide individualization services.