• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.6
• /
• pp.683-691
• /
• 2011

In order to develop technology for an equipment qualification (EQ) test, which is an important process in localizing solenoid-operated valves used in nuclear power plants, we analyzed related regulations, test procedures, conditions, equipment, and acceptance criteria. EQ regulations for the solenoid-operated valve are classified as law, guide, and standard, and are subdivided according to test specimens and contents. The EQ test is composed of functional, normal-, and accident- condition tests. The solenoid-operated valve is aged under normal and accident conditions, which are predicted in the design conditions of a nuclear power plant, and the performance of the valve is measured by a functional test. The test method and procedure analyzed in this paper might be very useful for manufacturers as well as EQ testers.

• Journal of Broadcast Engineering
• /
• v.22 no.1
• /
• pp.95-106
• /
• 2017

Interest in companion screen services and high-definition television broadcasting services are rising along with the advanced of digital broadcasting communication technology. Not only providing good-quality broadcasting services in the main screen, but also creating added values of companion services in the secondary screen are important. In this paper we suggest a platform and a related authoring tool generating adaptive companion screen services according to user contexts. The Platform providing adaptive companion screen services based on user environment is designed and implemented for real service market. Proposed platform organizes a higher quality content service considering both user contexts and demands of service providers in real time, and the related authoring tool enables a novice user interface designer and service director to make adaptive user interfaces quickly and easily. We developed and simulated this platform in accordance with Korean UHD IBB standard which provides interactive service applications.

• Journal of Korea Water Resources Association
• /
• v.31 no.5
• /
• pp.553-564
• /
• 1998

For the proper design and management of underground storage cavern, groundwater flow around cavern should be analyzed. Since this flow is influenced by spatial nonuniformity of hudraulic conductivity, the two-dimensional finite element flow model incorporating stochastic concepts was developed to analyze influences due to this nonuniformity. Monte Carlo technique was applied to obtain an approximate solution for two-dimensional, steady flow in a stochastically defined nonuniform medisu. For this purpose, the values of hydraulic conductivity were generated for each element with known mean and standard deviations. The uncertainty in model prediction depends on both the nonuniformity in hydraulic conductivity and the natures of the flow system such as water curtain and boundary condition. Therefore the uncertainties in predicted hydraulic head and gradient are the greatest where the mean hydraulic gradients are relatively large and far from the boundaries. Especially, we relate these uncertainties with well known gas tightness condition.

• Journal of the Korean Society for Railway
• /
• v.15 no.5
• /
• pp.467-475
• /
• 2012

Static and dynamic train load tests were conducted to evaluate the train load transfer mechanism in the roadbed which was retained by two types (fully and partially) of segmental retaining walls reinforced by geogrid. The test roadbed was 2.6m high, 5m wide, and 6m long. A combination of earth pressure gages, displacement transducers, and strain gages were placed in specific locations to measure the responses. Test results showed that the wall displacement pattern as well as the earth pressure for the fully reinforced retaining wall was different from those for the partially reinforced retaining wall. In the dynamic train load test, the strain in the upper part of the wall tended to decrease, and both the residual deformation and the rate of the deformation were significantly lower than those in the current design standard.

• KIEAE Journal
• /
• v.3 no.3
• /
• pp.35-42
• /
• 2003

It is required impressive expression of urban night environment that makes city as the safe pleasant, convenient place for the economic activity, cultural pleasure and landmarks. This study aims to establish the proper direction to the outdoor lighting in Seoul by analyzing and comparing the lighting situation and policies among Seoul, Shanghai and Yokohama. 1986 Asian Game and 1988 Olympic Game became very important role of activation of outdoor lighting in Korea. Then, outdoor lighting were facilitated in the cultural heritages and bridges along Han river. Millenium Light Plan, Outdoor Lighting Field of Seoul Architectural Award, 2002 Lightscape Local Plan, hosting 2002 World Cup have been good opportunities for the improvement of outdoor lighting in Seoul. In China, outdoor lighting was introduced to the city of Shanghai according to the orders of the president in 1988. Outdoor lighting of Shanghai have created unique lighting with beautiful color and intensive brightness under the direction of city government. Outdoor lighting of Shanghai needs the standard of lighting design and improvement of lighting facilities. Outdoor lighting was introduced to Japan with 1964 Tokyo Olympic games. Urban outdoor lighting plan was carried out in Yokohama in 1986. In Yokohama, outdoor lighting of civilian and public facilities have been harmonized. And the city government of Yokohama established the committee of promotion of outdoor lighting in its government to support and manage the outdoor lighting with corporation of civilian organization. As the result of comparative analysis on Seoul, Shanghai, Yokohama, Seoul Metropolitan Government needs the criteria and incentive system of outdoor lighting.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.20 no.2
• /
• pp.1-9
• /
• 2016

The authors performed the experimental work to propose the strength prediction equation for high strength concrete based on the non-destructive test methods. The concrete specimens that the range of design compressive strength was 40~80 MPa was produced in laboratory, and then tested rebound test and ultrasonic velocity methods and also compressive test according to the Korea Standard. The test results was compared with previously equations suggested by other researcher. From the test, these traditional nondestructive methods are simple, quick, has proven to be reliable and useful method for predicting the concrete strength. The test results were compared with the previous equations and then newly proposed own equations based on the test results. The proposed equations have the suitable precision and accuracy for applying the high strength concrete structures.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.38 no.11
• /
• pp.881-887
• /
• 2014

This paper presents numerical study on flow and heat transfer characteristics in micro-gap plate heat exchanger. In particular, we investigate the effect of flow inertia on the flow distribution from single main channel to multiple parallel micro-gaps. The flow regime of the main channel is varied from laminar regime (Reynolds number of 100) to turbulent regime (Reynolds number of 10000) by changing the flow rate, and non-uniformity of the flow distribution and temperature field is evaluated quantitatively based on the standard deviation. The flow distribution is found to be significantly affected by not only the header design but also the flow rate of the main channel. It is also observed that the non-uniformity of the temperature field has its maximum at the intermediate flow regime.

• Journal of the Korean Geotechnical Society
• /
• v.36 no.6
• /
• pp.17-34
• /
• 2020

In response spectrum analysis of pile-supported structure, an amplified seismic wave should be used as the input ground acceleration through the site-response analysis. However, each design standard uses different input ground acceleration criteria, which leads to confusion in determining the appropriate input ground acceleration. In this study, the ground accelerations were calculated through dynamic centrifuge model test, and the response spectrum analysis was performed using the calculated ground acceleration. Then, the moments derived from the test and analysis were compared, and a method for determining the appropriate input ground acceleration in response spectrum analysis was presented. Comparison of the experimental and simulated results reveals that modeling of the ground using elastic springs allows proper simulation of the natural period of the structure, and the use of a seismic wave that is amplified at the ground surface as the input ground acceleration provided the most accurate results for the response analysis of pile-supported structures in sands.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.11 no.1
• /
• pp.77-84
• /
• 2011

The methods of the rational formula and Kajiyama formula have been widely used for estimating the peak flood for design to all kind of hydraulic structure. However, there are many limitations and we have to apply these methods to ungauged basin. These methods require to calculate the Probable Maximum Precipitation (PMP) before determining the Probable Maximum Flood (PMF). Creager's method (Creager et al., 1945) is a kind of estimation of specipic flood and this method provided nonlinear equations based on relationship between the drainage area and PMF in order to calculate the PMF of multipurpose dams over medium-sized. But this method has not much applied in Korea. Creager's coefficient is not clear about its application because this method has never been applied to dams in Korea. Based on the PMP for rainfull-runoff models with the PMF of small and larger dams in this research, the range and standard of Creager's coefficients with parameters are proposed to apply basin areas in Korea.

• Korea Journal of Hospital Management
• /
• v.26 no.3
• /
• pp.68-83
• /
• 2021

Background: It is widely acknowledged that single bedrooms have many potential advantages compared to multiple bedrooms. However, Korea has a reimbursement system that patients have to pay the additional fee if they will use single bedroom or pay-bed (1-3 bedroom). There is little research on patients' bed selection and relationship between patient satisfaction and bed type in the Korean setting. Methods: Using the 2017 Korea Health Panel (KHP) Survey data, we modified bed type by two dichotomous variables: single bedroom vs. multiple bedroom (2+ bedrooms) and pay-bed (1-3 bedroom) vs. reimbursed bed (4+ bedroom). Multivariate logistic regression is performed to determine the factors affecting the patient's choice of room types. Multivariate regression analysis was conducted to examine how hospital room types are affecting patient satisfaction. Results: Single room and pay-bed (1-3 bedroom) use was influenced by patient age (19- years old), male, a person at work, hospitalizing in a clinic, and birth. After controlling variables of the behavioral model of medical utilization, the association between patient satisfaction and use of single bedroom & pay-bed (1-3 bedroom). Cause of hospitalization, major treatment, and recognition of unnecessary care are statistically significant variables on patient satisfaction. Conclusion: Although the single room is about the standard for newly built hospitals in western countries, it remains unclear that single room or pay-bed (1-3 bedroom) has positive effects on patient's outcomes and satisfaction. In this empirical study, the difference in patient satisfaction by bedroom type was not noticeable. In terms of bed management by hospital staff, securing patient credibility in hospital care is an important task. Patients' perception of whether medical staffs have encouraged unnecessary treatment or tests has a significant impact on patient's satisfaction.