• Korean Journal of Soil Science and Fertilizer
• /
• v.32 no.3
• /
• pp.211-214
• /
• 1999

To acknowledge the differences in soil physical properties of cultivated land derived from major parent rocks in Yeong-nam areas, we investigated Riley's projection sphericity(one of the morphological properties) of sand and made up Soil Moisture Characteristics Curve(SMCC). The averages in Riley s projection sphericity range from 0.63 to 0.67 in soils derived from Sedimentary rocks than 0.56 to 0.61 in soils derived from igneous rocks. In case of soils derived from igneous rocks, the Riley's projection sphericity is lower as the particle size get to be smaller. The differences of SMCC were larger in the fine loamy soils than in coarse loamy soils. The moisture retention was higher in the soils derived from Sedimentary rocks than in the soils derived from Igneous rocks. After we transformed the water retention into dimensionless scale value by available water ratio, the SMCC was nearly unchangeable in the tested soils except for fine loamy soils derived from Sedimentary rock, but was not correlated with soil texture or parent rocks.

• Journal of Korea Water Resources Association
• /
• v.40 no.8
• /
• pp.665-675
• /
• 2007

An equation is developed to estimate potential groundwater resources available for development. This equation is useful for preliminary planning stages prior to detailed design stages. The equation is a function of major factors such as aquifer characteristics, saltwater intrusion length, coastal groundwater discharge and potential locations of pumping wells. Thus, most important factors are taken into account. The equations are derived using well-known analytical solutions. Thus, the basis is scientifically sound. Use of the equation is quite simple since it is an explicit function of variables. A logical method is proposed to assess a radius of influence of a pumping well considering aquifer characteristics and the pumping rate. Applications to a hypothetical problem and comparison with results from a more rigorous numerical simulation model indicate that results obtained from the proposed equation are conservative.

• International Journal of Highway Engineering
• /
• v.12 no.1
• /
• pp.61-69
• /
• 2010

In this paper, we present the methodology about an optimal probability distribution selection as well as survival rate estimation with the national highway database from 1999 to 2008. Probability paper methods are adopted to estimate the parameters of each hazard model. The goodness-of-fit test, such as the Anderson-Darling statistics, was performed. As a result, we found that Lognormal distributionan is an appropriate distribution of newly constructed sections as well as overlayed sections. We also ascertained that the results of survival rate for pavement life between the proposed method and observed data are similar. Such a selection methodology and measures based on reliability theory can provide useful information for maintenance plans in pavement management systems as long as additional life data on pavement sections are accumulated.

• The Journal of the Korea Contents Association
• /
• v.15 no.8
• /
• pp.532-543
• /
• 2015

Damage of national infrastructures not only endangers the structural safety, but also has a direct and indirect influence on national economy and society. Since the influence of damage has been enhanced in the metropolitan areas, the infrastructures in danger should be identified and managed under disaster situations. This study suggests the importance factors for national infrastructures, calculates weights for the factors through AHP analysis, and develops the importance evaluation system for national infrastructures. The evaluation system provides the priority of infrastructures for local governments and facility managers and enables management based on the degree of importance in emergency situations. After disasters, the evaluation system will support a systematic decision-making for recovery priorities with a limited budget.

• The Journal of the Korea Contents Association
• /
• v.13 no.8
• /
• pp.211-228
• /
• 2013

In this study, it has conducted the questionnaire in the Seoul, Gyeonggi Province and DaeGu, GyeongBuk Province among males and females from 30s to 60s randomly to consider if the socio-demographical variance and the life style will meaningfully affect the preference of the silver town among elderly consumers as well as the future silver consumers. SPSS Win Ver.18.0 was used to analyze the statistical management of the collected data. As a consequence, among the socio-demographic variances, it was analyzed that the academic ability and religions were meaningfully affecting the preference of the silver town statistically, and after assaying how the characteristics of the life style affects the preference of the silver town, the more the family pursues the conservative life style the lower the preference of the silver town was observed, the more the life style covets the health, safety and the materials, the higher the preference of the silver town was analyzed. In addition, it was analyzed life style and the preference of the silver town showed a difference depending on the socio-demographic variances.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.28 no.1
• /
• pp.87-94
• /
• 2001

A survey was undertaken among a group of dentists working at private dental clinics to investigate the state of dental care and the level of education and training in the dental care to people with handicaps. Forty four percents of dental clinics take care of one more patients per month. The types of handicaps were physical, mental, sensory handicap and autism. The common problems are difficulty in communication and delay of treatment. Forty nine percents of dentists got education and nineteen percents had clinical experience for dental care of handicapped patients. Most of dentists felt necessity of training program and establishment of specialized dental hospital supported by government for the handicapped. This study indicated the necessity of undergraduate and postgraduate education and clinical training for dental care of handicapped patients.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2006.11a
• /
• pp.361-366
• /
• 2006

As time goes by, educational facilities have become superannuated and damaged; therefore, performance and safety of buildings have been decreased. It causes the decrease of service quality and deterioration of educational environment. In order to protect facilities from serious damages and deterioration, a consistent maintenance and repair program is required. The educational facilities can keep the good educational environments and also make better environments through the program. This study is made by investigating and analyzing the maintenance data which was collected from fifty schools in Asan area, Chungchengnam-do in order to derive foundation data for the efficient educational environment maintenance program.

• Journal of Energy Engineering
• /
• v.16 no.3
• /
• pp.103-112
• /
• 2007

Flood issue for nuclear power plants designed and built in 1970 is extremely severe for main steam header compartment and main feedwater line region of intermediate building and lower floor. A calculation for flood level at the main feedwater line isolation compartment is now performing by hand calculation. But, this methodology is quite conservative assumption. The goal of this study was to develop method to analyze flowrate using the RETRAN-3D computer code, and the developed method was applied to flood level analysis following main feedwater line break. As a result of analysis, flood level was low remarkably.

• Journal of Korean Society of Transportation
• /
• v.31 no.2
• /
• pp.80-89
• /
• 2013

The purpose of this research is to optimize the line planning of the intercity passenger railway. In this study, the line planning problem has been formulated into a mixed integer programming by minimizing both user costs (passenger's total travel time) and operator costs (operation, maintenance and vehicle costs) with multiple train types. As a solution algorithm, the branch-and-bound method is used to solve this problem. The change of travel demand, train speed and the number of schedules have been tested through sensitivity analysis. The optimal stop-schedules and frequency as well as system split with respect to each train type have been found in the case study of Kyoung-bu railway line in Korea. The model and results of this research are useful to make a decision for railway operation strategy, to analyze the efficiency of new railway systems and to evaluate the social costs of users and operators.

• Korean Journal of Construction Engineering and Management
• /
• v.16 no.2
• /
• pp.3-11
• /
• 2015

The urban has been improved houses and facilities as accelerating industry and society, while the rural area was inferior to the city. Furthermore, there was not a maintenance in time as ageing, and did not expect to rebuilding of using proper techniques and materials for financial reasons. This study find a way to make a revitalizing plan for appropriate real state. For this, perform a current status survey that 900 rural residences of 36 rural villages in Chungcheong area. As a result, Korean traditional structure is a half in residential type, and has poor residential conditions by comparison with western pattern. The structural type comprises two type that a pure structure and a mixed structure, and Korean traditional structure is a mixed structure more than a pure structure. It is considered continuous changes by a resident due to a pure structure was not satisfy various functions. It need appropriate plan to improve a rural residence for each characteristics.