• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.3
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• pp.344-349
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• 2006

The low-temperature processing is very important for fabrication of the very large scale ($60{\sim}70nm$) semiconductor devices since the submicron transistors are sensitive to the thermal budget. Hence, in this work, we propose a noble low-temperature LPCVD (Low-Pressure Chemical Vapor Deposition) process for the $SiO_2$ film and evaluate the electrical reliability of the LTO (Low-Temperature Oxide) by making the capacitors with ONO (Oxide/Nitride/Oxide) structure. The leak current of the LTO was similar to that of the high-temperature wet oxide until the electric field was lower than 5 MV/cm. However, when the electric field was higher, the LTO showed much better characteristics.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.4
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• pp.62-72
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• 2015

Nowadays the issue of aging society has received considerable critical attention, especially in transportation planning and demand forecasting. This study identified the factors related to travel time budget for elderly by purpose using seemingly unrelated regression model (SUR model). The SUR model is suitable when error terms of each equation are assumed to be correlated across the equations in terms of travel time budget which is constant in 2 hours per day commonly. The results showed that elderly's travel time budget was affected by individual, household, urban facility and transportation service. The leisure travel comprised a large proportion of total travel time and had a positive relationship with elderly, sports, religious facilities. Moreover, the elderly who had low income or unemployed person had low frequency of social activity such as leisure, shopping and business. This study can provide a comprehensive implications of forecasting the future travel demand and analyzing the travel behavior.

• Korean Journal of Construction Engineering and Management
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• v.23 no.3
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• pp.13-24
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• 2022

Construction projects are exposed to various types of risks, which tend to increase. The increasing risks call for contractors' more attentions to forecasting and dealing with these risks. One of the measures to deal with contractors' risks is to forecast or estimate risk cost and include it in the construction budget. Although various researches in relation to risk cost have been observed, little attention has been paid to general contractors' perceptions and current practices in estimating risk cost of construction budget. The objective of the study is to identify and discuss key characteristics and implications based on the survey and analysis of general contractors' perceptions and current practices in estimating risk cost of construction budget. The study shows that there is a gap between the perception and the practice of estimating risk cost, that is, high perception of the importance of risk cost and a relatively low level of practice. It suggests that historical cost data, guidelines and corporate-level standard procedures are required to improve the current practice in addition to sufficient time allocations for risk cost estimating. It discusses that there is a need for using sophisticated estimating techniques including bid data analytics despite a low level of the current adoption, and also proposes that research and development in the field of the sophisticated estimating techniques should be further implemented in order to increase their practicality.

• The Journal of Sustainable Design and Educational Environment Research
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• v.8 no.1
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• pp.11-22
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• 2009

School is a basic and the most fundamental facility of city planning just like other basic public facilities including the village office. Every plan is established on the basis of school. However, the problems such as the population reduction resulting from the nuclear family-zation and low birth rate, employment and welfare of the aged people resulting from "the old aged society", and the infant nursing and education resulting from a rapid increase of the working couples become notable and accordingly more requirements are being made. Reflecting this trend, the concept and operation system should be changed. Up to now, the BTL projects of the educational facilities are gaining a reputation of being efficient in terms of national budget running, but at the same time receiving negative reputation in terms of budget saving under the civil creativity and efficiency. Through upgrading the private sector investment projects into the BTO+BTL system and further into the BTO(Build Transfer Operate), we can accomplish the original goals of the private sector investment projects, and can make the education budget operation more efficient, and can greatly improve the education environments. However, we should not underestimate in this process that these facilities should not negatively affect the education environments. In any situation, the owners of schools are students.

• The Journal of Korean Physical Therapy
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• v.10 no.1
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• pp.105-125
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• 1998

We are confronted by increase in old people due to the improvement in medical science, public hygiene and socioeconimic status in 20th century. But our medical security system for old people dees not meet the need for medical service of old people. Current medical insurance system restricts term and extent in allowance although the characteristics of the disease of the aged people need medical care of Bong duration and high cost. And in the medicaid system the speciality of the aged people is not recognized and the budget of the government is scanty. In addition many old people to our country are in economic distress due to low income. But the government authority does not give sufficient consideration for eld people in law, policy and budget. To improve social security system for old people it is necessary to increase the budget for the security of old people, to enhance the traditional respect for the aged, to improve medical security system by improving the accessibility to medical service and by expanding the allowance of medical insurance, and to expand the public welfare institutions. And these are roles for all the family. the society and the nation as well as the aged people themselves.

• Journal of Korean Society of Rural Planning
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• v.8 no.2 s.16
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• pp.42-49
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• 2002

Since legislation of Rural Minor Road Improvement Act 1990, a quarter of its total length had been paved now. However, over 80% of arterial road length(national+provincial roads) had been paved, so, road improvement policy should be focussed on the local road(county+rural minor roads) from now. Generally, in the greater part of coastal plain and island areas, arterial road intensity(total road length/total catchment area) is relatively low, but local road intensity is relatively high. So, in terms of balanced development, much more efforts for rural minor road improvement should be concentrated in coastal plain and islands areas. In Chonnam Province, the maximum differentials of minor rural road improvement ratio was over 20%(the lowest; 14.1% in Goheung, the highest; 35.6% in Goksung) in 1999, but the improvement budget have been allocated in proportion to unpaved road length of each county by the provincial government. However, the differentials should not be fairly narrowed in the near future if the present budget allocation policy be maintained. To solve this problem, target differentials of rural minor road improvement between regions should be set up for each planning year and road improvement budget be allocated according to this policy change.

• Journal of Astronomy and Space Sciences
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• v.33 no.4
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• pp.335-344
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• 2016

Scientific CubeSat with Instruments for Global Magnetic Fields and Radiations (SIGMA) is a 3-U size CubeSat that will be operated in low earth orbit (LEO). The SIGMA communication system uses a very high frequency (VHF) band for uplink and an ultra high frequency (UHF) band for downlink. Both frequencies belong to an amateur band. The ground station that communicates with SIGMA is located at Kyung Hee Astronomical Observatory (KHAO). For reliable communication, we carried out a laboratory (LAB) test and far-field tests between the CubeSat and a ground station. In the field test, we considered test parameters such as attenuation, antenna deployment, CubeSat body attitude, and Doppler frequency shift in transmitting commands and receiving data. In this paper, we present a communication performance test of SIGMA, a link budget analysis, and a field test process. We also compare the link budget with the field test results of transmitting commands and receiving data.

• Journal of Integrative Natural Science
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• v.8 no.4
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• pp.293-304
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• 2015

This study examined the factors which have influence on the welfare facilities for the elderly and analyzes their efficiency. It investigated theoretical studies and preceding studies and divided the efficiency evaluation factors into input and output factors. Input factors included budget, the number of workers and clients and facility area and output factors were operation management, the number of clients, profitability and welfare for the elderly. To sum up the analysis results of evaluation factors of welfare facilities for the elderly, the analysis of relative importance of input showed that budget was most important. As a result of analyzing the relative importance among detailed items, balance sheet and professional manpower were highest. Input factors by facility types showed that the budget for utility facilities and living facilities were highest. In output factors, utility facilities and living facilities were highest in management systematization and welfare for the elderly, respectively. In efficiency evaluation, utility facilities for the elderly showed 100% of efficiency in CCR and BCC models. In welfare facilities for the elderly, while CCR model showed 100% of efficiency in facility types A, C, D, and F, the efficiency was low in facility B (79.89%), E (77.14%), and G (80.72%). In BCC model, facility E was low as 78.69%. In efficiency comparison between utility facilities and living facilities for the elderly welfare, the efficiency of utility facilities for the elderly welfare was higher. Therefore, this study investigated the efficiency of welfare facilities for the elderly as its main purpose and presented policy suggestions based on the research results as the alternative.

• Korean Journal of Ecology and Environment
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• v.37 no.3 s.108
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• pp.272-281
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• 2004

The Primary production and budget of organic carbon at rainy and dry period was surveyed to evaluate the contribution of primary production in Paldang Reservoir. Primary productivity of phytoplankton showed remarkable differences depending on sampling dates and sites, ranged from 110 to 2,701 mgC $m^{-2}day^{-1}$. In the rainy period of April and August when there had been frequent rainfall resulting short hydraulic retention time and low algal biomass in Paldang Reservoir, autochthonous organic carbon occupied very low ratio, farming approximately 7 percent of total inflow of organic carbon. However in June when it almost never rained and dominant algal species changed from diatoms to green algae and small flagellates, autochthonous organic carbon from primary productivity of phytoplankton formed 29 percent of total inflow of organic carbon.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.53.2-53.2
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• 2010

In this study, we focused on our specialized electrode process for Si back-contact crystalline solar cell. It is different from other well-known back-contact cell process for thermal aspect and specialized process. In general, aluminum makes ohmic contact to the Si wafer and acts as a back surface reflector. And, silver is used for low series resistance metal grid lines. Aluminum was sputtered onto back side of wafer. Next, silver is directly patterned on the wafer by screen printing. The sputtered aluminum was removed by wet etching process after rear silver electrode was formed. In this process, the silver paste must have good printability, electrical property and adhesion strength, before and after the aluminum etching process. Silver paste also needs low temperature firing characteristics to reduce the thermal budget. So it was seriously collected by the products of several company of regarding low temperature firing (below $250^{\circ}C$) and aluminum etching endurance. First of all, silver pastes for etching selectivity were selected to evaluate as low temperature firing condition, electrical properties and adhesive strength. Using the nano- and micron-sized silver paste, so called hybrid type, made low temperature firing. So we could minimize the thermal budget in metallization process. Also the adhesion property greatly depended on the composition of paste, especially added resin and inorganic additives. In this paper, we will show that the metallization process of back-contact solar cell was realized as optimized nano-paste characteristics.