• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.3
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• pp.82-90
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• 2006

Recently the electrostatic 2-axis MEMS stages have been fabricated for the purpose of an application to PSD (Probe-based Storage Device). However, all of the components(platform, comb electrodes, springs, anchors, etc.) in those stages are placed in-plane so that they have low areal efficienceis, which is undesirable as data storage devices. In this paper, we present a novel structure of an electrostatic 2-axis MEMS stage that is characterized by having large area platform. for obtaining large area efficiency, the actuator part consisting of mainly comb electrodes and springs is placed right below the platform. The structure and operational principle of the MEMS stage are described, followed by a design procedure, structural and modal analyses using FEM(Finite Element Method). The areal efficiency of the MEMS stage was designed to be about 25%, which is very large compared with the conventional ones having a few percentage.

• Journal of the Korea Society of Computer and Information
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• v.10 no.4 s.36
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• pp.221-228
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• 2005

Data storage was thought to be inside of or next to server cases but advances in networking technology make the storage system to be located far away from the main computer. In Internet era with explosive data increases, balanced development of storage and transmission systems is required. SAN(Storage Area Network) and NAS(Network Attached Storage) reflect these requirements. It is important to know the capacity and limit of the complex storage network system to got the optimal performance from it. The capacity data is used for performance tuning and making purchasing decision of storage. This paper suggests an analytic model of storage network system as queuing network and proves the model though simulation model.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.5
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• pp.71-81
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• 2013

This study is aimed to provide basic data for the estimation of carbon effects in development project areas such as Happy Housing Project which includes redevelopment and reconstruction projects by inducing the basic unit of carbon effects and strategic planning and management to enhance carbon effects. According to the analysis, in urban parks, carbon uptake and carbon storage by the unit area of living area parks were $7.614kg/m^2$ and $18.5203kg/m^2$ respectively while carbon uptake and carbon storage by the unit area of theme parks were $1.2261kg/m^2$ and $2.831kg/m^2$ each. In facility greens, carbon uptake and carbon storage were $0.5683kg/m^2$ and $0.6636kg/m^2$ respectively while they were $10.77kg/m^2$ and $13.69kg/m^2$ individually in other urban planning facilities. In other greens, on the contrary, carbon uptake and carbon storage were $0.45kg/m^2$ and $1.02kg/m^2$ respectively. In site landscape, carbon uptake and carbon storage by the unit area of apartment landscape were $3.7394kg/m^2$ and $9.2292kg/m^2$ each.

• Journal of Environmental Science International
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• v.22 no.2
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• pp.139-149
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• 2013

Anthropogenic increases in greenhouse gas concentrations, primarily through radiative forcing from carbon dioxide, continue to challenge earth's climate. This study quantified $CO_2$ storage and uptake by dominant forest types and age classes in the middle region of Korea. In addition, the role of forest landscapes in reducing atmospheric $CO_2$ against $CO_2$ emissions based on energy consumption was evaluated. Mean $CO_2$ storage and uptake per unit area by woody plants for three forest types and four age classes were estimated applying regression equations derived to quantify $CO_2$ storage and uptake per tree; and computations per soil unit area were also performed. Total $CO_2$ storage and uptake by forest landscapes were estimated by extrapolating $CO_2$ storage and uptake per unit area. Results indicated mean $CO_2$ storage per unit area by woody plants and soils was higher in older age classes for the same forest types, and higher in broadleaved than coniferous forests for the same age classes, with the exception of age class II (11-20 years). $CO_2$ storage by broadleaved forests of age class V (41-50 years) averaged 662.0 t/ha (US$331.0 hundred/ha), highest for all forest types and age classes evaluated. Overall, an increased mean $CO_2$ uptake per unit area by woody plants was evident for older age classes for the same forest types. However, decreased $CO_2$ uptake by broadleaved forests at age class V was observed, compared to classes III and IV with an average of 27.9 t/ha/yr (US$14.0 hundred/ha/yr). Total $CO_2$ storage by woody plants and soils in the study area was equivalent to 3.4 times the annual $CO_2$ emissions, and woody plants annually offset the $CO_2$ emissions by 17.7%. The important roles of plants and soils were associated with 39.1% of total forest area in South Korea, and $CO_2$ emissions comprised 62.2% of the total population. Therefore, development of forest lands may change $CO_2$ sinks into sources. Forest landscape management strategies were explored to maintain or improve forest roles in reducing atmospheric $CO_2$ levels.

• Water for future
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• v.28 no.5
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• pp.129-140
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• 1995

In this study we derived steady-state relationships between surface saturation area and subsurface outflow, and between surface saturation area and soil moisture storage through numerical experiments with Richards equation on a hillslope. Numerical experiments analyzed the sensitivity of topographic and soil hydraulic properties on steady-state relationships between surface saturation area and subsurface outflow. And the power law for the extent of surface saturation area was determined as a function of subsurface outflow or soil moisture storage.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.373-378
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• 2004

Recently the electrostatic 2-axis MEMS stages have been fabricated for the purpose of an application to PSD (Probebased Storage Device). However, most of them have low area efficiency, which is undesirable as data storage devices, since all of the components (springs, comb electrodes, anchors, platform, etc.) are placed in-plane. In this paper, we present a novel structure of electrostatic 2-axis MEMS stage that is characterized by having large area platform. For large area efficiency, the actuator part consisting of mainly comb electrodes and springs is placed right below the platform. In this article, the structures and operational principle of the MEMS stages are described, followed by design procedure, structural and modal analysis using FEM(Finite Element Method). The area efficiency of the MEMS stage was designed to be about 55％, that is very large compared with conventional ones having a few percentage.

• The Journal of the Korea Contents Association
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• v.9 no.1
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• pp.23-29
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• 2009

This paper presents a capacity estimation of a storage system accumulating all data sensed during the lifetime of an individual human being. The calculation assumes modern data compression and data collection schemes based on wearable or implanted devices under ubiquitous environment. More than 76% of the storage area is found to be used for video data storage of common TV image quality. The remaining storage area is for data from other sensing organs including audio, taste, olfactory and tactual systems in addition to indexing information. Total storage area of around 600 tera bytes is needed to cover 100 years of human life including his fetal period.

• Proceedings of the Korea Contents Association Conference
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• 2004.11a
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• pp.275-279
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• 2004

In this paper, a large-scale, wide-area storage system based on IP is proposed which is under development. OASIS is a storage system enforced with very high-scalability up to hundreds and thousands of clients over IP network, and it is able to extend the service to the wide area network. For this purpose, we adopt an storage interconnection technology based on IP, the object based storage technology and a clustered server architecture which provides high-scalability and availability to our system. This system can be utilized to provide network storage service which gains more reality with the incoming FTTH and WiBro services.

• Journal of the Korean housing association
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• v.21 no.3
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• pp.53-65
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• 2010

The purpose of this study is to develop a checklist based on the stored items of cooking, for making a good kitchen furniture reseach. The research candidates are purposive sampled from 30 households of for 40 or 50 pyeong-type apartments in Kangnam, Seoul, The research data are is collected gotten at by a field study of the stored items of cooking, eating and utility area, by an in-depth interview to 30 households, and by a field survey of the department stores, super-markets of home appliances. Studied households in average hold about 890 items, which are classified as 239 sorts. The first step of making the checklist is to categorize items into 9 biggest categories, considering the usage of items and the stage of the preparing the food. when the item was used. Second step of making the checklist is to categorize the items into 31 smaller categories, which reflect the shape of items, the storage style and the place of storage. Third step of making the checklist is to sort the items into smallest categories by the frequency of the usage, storage type, and the additional capacity of the item. Even Although items are sorted into the same level of categories, the frequency of use make a different storage area. Also, the storage style of the items was different according to the storage area. Based on these factors, we suggested a checklist based on the stored items of cooking.

• Journal of Korean Society of Forest Science
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• v.85 no.1
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• pp.66-75
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• 1996

This study was carried out to examine the forest fire effect on water storage characteristics in the forests. Water storage capacity of the burned area was analyzed by several major factors, such as soil pore, maximum water content, effective water storage, and percolation rate. The results obtained from the analysis of major factors are as follows; The deeper soil depth, the less total pore, coarse pore, effective water storage, and percolation rate. However, fine pore increased slightly in both burned area and control plot. As compared with control plot, burned area showed lower percolation rate, coarse pore, and effective water storage, but higher values of fine pore. Directly after forest fire, the soil pore is little affected. But as the time passes, top soil structure changes and soil pore also is affected even in a deep soil. Estimated effective water storage was lower at top soil of Namcheon and at deep soil of Namha in all the burned areas, but slowly decreased in deep soil compared to control plots. Therefore it was concluded that forest water storage capacity was greatly affected by the forest fire.