• The Transactions of the Korean Institute of Power Electronics
• /
• v.11 no.5
• /
• pp.409-416
• /
• 2006

Operating Characteristics of LLC Series resonant converter with a LLT(Inductor-Inductor-Transformer) transformer is presented. LLT transformer used to combine the inductor and transformer into one unit has the increased leakage inductance in the primary and secondary due to the winging method and the use of the gaped core. The increased leakage inductance in the primary and secondary of LLT transformer can be impacted on the DC voltage gain characteristics of LLC series resonant converter. In the paper, DC gain characteristics and the experimental results of the LLC series resonant converter with a LLT transformer are verified on the simulation based on the theoretical analysis and the 400W experimental prototype.

• Textile Coloration and Finishing
• /
• v.22 no.2
• /
• pp.173-179
• /
• 2010

In this study, we determine the stretch and shrinkage properties of conjugated yarns. The shrinkage(%) and elasticity(%) were determined by applying twist conditions of 0, 350, 800, 1000, 1200, 1400, 1600, 2000 T/M (twisting per meter). It is found that the shrinkage(%) and elasticity(%) gradually decreased with increasing T/M. Especially the elasticity(%) dramatically decreased over 1400 T/M condition. In contrast, it is showed that the handle and drapery properties decreased below 1000 T/M, which indicates that the optimal T/M condition could be 1000~1400. The effect of shrinkage(%) and elasticity(%) with different steam setting temperatures (60, 70, 80 and $90^{\circ}C$) was also determined. The shrinkage(%) decreased with increasing setting temperature, while the elasticity not changed. In this context, the optimal steam setting temperature could be $80^{\circ}C$ because it is not easy to weave with the yarns which was set below $80^{\circ}C$. The elasticity(%) decreased with increasing the density of warp and weft. To produce soft handle, excellent drapery and good stretch fabrics, the warp density needs to be reached by 90% of the ideal warp density. In the case of NaOH treatments to the fabrics, the elasticity(%) increased with increasing weight reduction. Therefore, this study have demonstrated that the conjugated yarns with core yarn and the SDY CD(cation dyeable spindraw yarn) as an effect yarn would be appropriate to produce excellent mixture-yarn, which displays clean appearance, good handle and excellent elasticity, The optimized conditions are as follows; 1000~1200 twist per meter, $80^{\circ}C$ steam setting temperature, 90% of ideal warp density and relaxation condition treated with 5g/l NaOH concentration.

• Journal of Broadcast Engineering
• /
• v.11 no.1 s.30
• /
• pp.107-115
• /
• 2006

In the environment of single application data broadcasting, only one application can be serviced at a specific time on one channel. To overcome this, we developed the structure and the method of operation for multi-applications which are fully conformant to the ACAP (Advanced Common Application Platform), and modified data broadcasting system to support multi-applications. In multi-application environment, broadcasters can service multiple applications simultaneously at a specific airtime on one channel so users can enjoy services selectively according to their preferences. In this paper, we present an example of multi-application service which was developed to make an experiment before servicing them to users on the air. The core of the multi-application is a manager application which manages other ordinary applications, so we describe the function and structure of the manager application, and then present the experimental results to show that the proposed method is the proper model for multi-applications.

• Korean Journal of Medicinal Crop Science
• /
• v.7 no.3
• /
• pp.172-176
• /
• 1999

The saponins are considered the main effective components in Platycodon grandiflorum (Jacq.) A. DC.. In order to obtain the basic information for producing the high quality medicinal plant and processing, the crude saponin contents were analyzed with platycodi radix, the root of Platycodon grandiflorum by different cultivating years, parts, harvesting times and drying methods. The crude saponin contents were decreased by increasing cultivating years. The crude saponin contents were 2.74% in tail of root and 1.65 % in head of root, respectively. Besides, the contents of the crude saponin in cortex were 1.8 times more than that in core of root. The crude saponin contents in different harvesting times were 2.82% and 2.74% at March 10 and December 10, showing higher than that being harvested at June 10 and September 10. The crude saponin contents among drying methods were not significantly different at 5% level DMRT, but the hot air drying after steam showed the least crude saponin.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.23 no.1
• /
• pp.11-17
• /
• 2011

A major source of durability problems in concrete structures is the corrosion of steel by the damage of passivity layer around steel bars. As chloride ion penetration is major cause of the destruction of passivity layer, evaluation of depth and concentration profile of chloride ion is the essential factor for the service-life estimation of concrete structure. To estimate chloride ion penetration characteristics, this paper on the basis of in-situ experimental data investigated the depth and concentration profile of chloride ion penetration. The core specimens are obtained at air-zone, splash zone, and tidal zone in Wando, Masan, Incheon, Gwangyang, and donghae harbors. Colorimentric method measured the chloride ion penetration depth and ASTM C 114 evaluated the concentration profile of chloride ion. Based on experimental data, the influence of harbor location and exposure condition on chloride ion penetration is evaluated.

• Journal of the Korean Institute of Rural Architecture
• /
• v.22 no.3
• /
• pp.49-60
• /
• 2020

The purpose of this study utilizes the service design methodology centered on the lives and experiences of rural residents, who are the main beneficiaries of the service, to derive specific problems and needs, and to propose a service improvement plan suitable for the rural residential environment. The study selected Dosan 2-ri Village, Hongseong-gun, Chungcheongnam-do as the target of the survey, used personas and Customer Journey map of service design method to derive specific core issues and insights from the village residents. By developing this, the final five service directions for 'Air care service', 'Self-driving garbage collection and treatment service', 'Emergency/disaster networking service', 'Contaminant removal service' and 'Mobility share service' were derived and presented according to each key keyword. This study is not just a study to grasp the actual conditions of the rural residential environment, but it focuses on the lives and experiences of rural residents and extracts elements that can respond to changes in the lifestyles and patterns of the residents. It can be used as a basic material for more realistic improvement of rural residential environment and service development research. Most of the existing studies on residential environments and spaces is focused on urban areas, and there is a limit to the use of rural areas in residential areas. Therefore, by making recommendations for improvement of residential environment services suitable for rural areas and by creating residential spaces and environments in rural areas in a comfortable and safe manner, it is thought that it is possible to contribute to improvement of satisfaction in rural areas and improvement of healthy housing welfare as well as to improvement of the quality of life of residents of rural areas.

• Journal of Korean Society for Quality Management
• /
• v.41 no.4
• /
• pp.567-580
• /
• 2013

Purpose: This study aims to develop measuring tools for 'Consumer Issues' of ISO 26000, the international standards for corporate social responsibility(CSR), and propose strategic suggestions on the CSR implemention by analyzing the differences among various industries. Methods: In order to test the research models, structured questionnaires were used and nationwide surveys were conducted targeting at customers who have had experiences in using the products and services from the companies which published CSR reports. In addition, for the empirical analysis of data, the models were verified with AMOS confirmatory factor analysis(CFA). Results: From the result of the analysis of differences among industries, it was shown that level of CSR activities was high in public sectors, followed by service industries and manufacturing. It was also shown high in air transport and the electrical and electronic industries, while it was confirmed low in energy and environment related industries such as energy, automobile and chemical industries. As a result, strategic approaches are suggested, considering the different characteristics of each industry in implementing CSR. Conclusion: This study has developed measuring tools for 'Consumer Issues' to research the core subjects and issues of ISO 26000, the international standards for CSR. It has confirmed the characteristics and differences regarding 'Consumer Issues' among industries and proved that industries can provide guidelines for the implementation of CSR activities through approaching and researching various issues from interested parties. This study has also suggested the importance of customer awareness of CSR activities and active communications by industries.

• Journal of the Korean Institute of Gas
• /
• v.22 no.4
• /
• pp.55-62
• /
• 2018

There is growing interest in solar power generation due to global warming. As a result, demand for polysilicon, which is the core material for solar cells, is increasing day by day. As the market grows, large and small accidents occurred in the production process. In 2013, hydrochloric acid leaked from the polysilicon manufacturing plant in SangJu. In 2014, a fire occurred at a polysilicon manufacturing plant in Yeosu, and in 2015, STC(Silicon Tetrachloride) leaked at a polysilicon manufacturing plant in Gunsan City. Leakage of chemicals in the polysilicon manufacturing process can affect not only the workplace but also the surrounding area. Therefore, in this study, we identified the hazardous materials used in the polysilicon manufacturing process and quantitatively estimate the amount of leakage and extent of damage when the worst case scenario is applied. As a result, the damage distance by explosion was estimated to be 726 m, and the damage distance to toxicity was estimated to be 4,500 m. And, if TCS(Trichlorosilane), STC(Silicon Tetrachloride), DCS(Dichlorosilane) leaks into the air and reacts with water to generate HCl, the damage distance is predicted to 5.7 km.

• Journal of KIISE:Information Networking
• /
• v.35 no.1
• /
• pp.11-20
• /
• 2008

An inevitable trend in the next generation wireless network environments is coexistence of different wireless access networks in a complementary, manner. In addition, mobile devices equipped with multiple air interfaces simultaneously executing diverse applications have been emerging, In such network environment, It is required that a solution for mobile users to seamlessly roam between different access networks as well as to satisfy QoS requirements of each application by efficiently utilizing coexisting various wireless access networks. In this paper, therefore, we propose a mobility management platform based on per-application end-to-end mobility management and cross-layer handover controls. Four core functional modules composing the proposed platform for end user devices are defined: Monitoring Agents, Profile Database, Decision Engine, and IP Agent. We show through simulations that the presented platform provides an improved QoS as it selectively utilizes the best available networks.

• Journal of Advanced Navigation Technology
• /
• v.19 no.3
• /
• pp.182-191
• /
• 2015

The automatic dependent surveillance - broadcast (ADS-B) system which is a core system of aviation system block upgrade is designed and implemented. The ADS-B system consists of the 4 blocks and 10 units, and filtering algorithm is applied to the implemented ADS-B system. To evaluate a performance of the implemented ADS-B system, real aircraft position data is used and compared reliable radar data. The comparison results show that average position difference of 99.57 m. In addition, comparisons of aircraft position data between the implemented ADS-B system employing filtering algorithm and the conventional ADS-B system under various situations are carried out, such as aircraft turning, taking off, landing, and cruising. The comparison results show that average position difference of 8.02 m.