• Design & Manufacturing
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• v.7 no.1
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• pp.40-44
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• 2013

My company develops, manufactures injection mold and produces thin-walled cosmetics and food containers. Without high quality and low production cost, it is hard to compete in the market. To be competitive, a company has to utilize mold with as many cavities as possible to lower manufacturing cost. Eject plate abrasion and deformation cut down mold lifespan, troubles during injection lower productivity and foreign substances in molds cause abrasion. This study focuses on how to improve mold life and productivity, and to slow down mold abrasion.

• Wind and Structures
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• v.10 no.1
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• pp.83-97
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• 2007

In the last decades there have been frequent reports of oscillations of slender tension members under simultaneous action of rain and wind - characterized by large amplitudes and low frequencies. The members, e.g. cables of cable-stayed bridges, slightly inclined hangers of arch bridges or cables of guyed-masts, show a circular cross section and low damping. These rain-wind induced vibrations negatively affect the serviceability and the lifespan of the structures. The present article gives a short literature review, describes a mathematical approach for the simulation of rain-wind induced vibrations, sums up some examples to verify the calculated results and discusses measures to suppress the vibrations.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.133-134
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• 2009

Although the sheaths exerts decisive influence on quality and lifespan of total structural, there is no clear definition about experiment methods on the sheaths in Korea. Therefore, this research is designed to come up with simple and efficient test measures suitable for domestic conditions by modifying the existing foreign standard

• KIEAE Journal
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• v.2 no.2
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• pp.15-22
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• 2002

Importation of mass production of building elements with standardization are vital way for environment-friendly architectural planning, which it makes the lifespan of a building longer than normal with easier maintenance and remodeling. The advantage might be magnified here in Korea since typical types of apartment house are dominated in our construction market. For the purpose, a series of pre-manufactured window systems is one of the optimal elements to be prototype building modules. In the design process of the system windows, lots of consideration should be involved and they include aesthetics, thermal performance, noise reduction, airtightness, and so forth. A real survey on the ready-made window systems has been performed and its optical issue related to luminous peculiarity is what is of major interest in this study. In addition, technical review on more advanced window products and their adaptable potential for the integration with fundamental architectural design elements were carried out.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.3
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• pp.223-231
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• 2015

LEDs have been widely used in lighting displays, automobiles, and airplanes owing to their excellent light output characteristics and long lifespan. Though LEDs are manufactured under the same process, variations in impurity concentrations cause electrical deviation among LEDs. The resulting electrical deviation can not only reduce the life time of the LED but also cause non-uniform luminance of LEDs connected in parallel. LED driving circuit is required to solve these problems. In this paper, we propose a LED driving system using Y-type current balancing transformer to maximize the efficiency of the system by removing output stage Schottky diodes. Experimental results are presented to verify the performance of proposed LED driving system that is applied to 80 W LED modules.

• Journal of Industrial Technology
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• v.29 no.B
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• pp.187-191
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• 2009

Recently, we have used LEDs to illumination because it has a high luminous efficiency and prolong lifespan. However the light power and lifetime is reduced by junction temperature increment of LED. So it is important to measure the junction temperature accurately. In case of using a electrical method measuring junction temperature of LED. Temperature measurement errors are spontaneously generated because of a parasitic capacitances in LED. In this paper, we proposed a method that reducing LED's parasitic capacitance effects for electrical measurement. It was demonstrated by the experimental result that is more correct than established method.

• Korean Journal of Pharmacognosy
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• v.33 no.3 s.130
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• pp.224-229
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• 2002

Sarcodon aspratus (Thelephoraceae), a native mushroom distributed in Korea and Japan has been widely used as a traditional food and folk medicines. Two proteoglycan polysaccharides, named SAP-A and SAP-B were isolated from the fruitbody of S. aspratus. Their molecular weight were determined as 6184.9 D, and 25749.2 D, respectively, by maldi-tof ms. The composition of sugar and amino acid of these compounds was also determined. The SAP-A showed potent antitumor activity. The $ID_{50}$ value of SAP-A was 8.2 mg/kg/day for ICR mice transplanted with solid sarcoma-180, and the elongation of lifespan effect was 167.4% for ICR mice transplanted with ascitic sarcoma-180. Moreover, the elongation life-span effect of SAP-A increased dose-dependently.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.28 no.3
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• pp.156-167
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• 2017

Childhood exposure to intimate partner violence (IPV) and other adversities has been shown to have adverse effects on health and well-being not only in childhood but also throughout the lifespan. This paper focuses on the prevalence of childhood adversities including exposure to IPV. The intersection of adverse childhood experiences and IPV victimization/perpetration in adulthood is also explored. The neurobiology of trauma is discussed and by understanding the impact of trauma on health, it is hoped that enhancement of resilience is possible. Based on the identification of protective factors at the individual, familial, and community level, examples of interventions that encourage safe, stable, and nurturing relationships between parents and children are described.

• The Korean Journal of Applied Statistics
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• v.24 no.4
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• pp.633-646
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• 2011

Clinical vaccines studies (that include cancer prevention vaccines and therapeutic vaccines) are ongoing to improve the quality of life and lengthen the human lifespan. Recently clinical trials and research on vaccines have become more active due to the prevalence of new viruses such as the A(H1N1) virus that freighted the whole word in 2009. In this paper we will describe the statistical aspects of clinical vaccine trials and outline the current situation of domestic and international vaccine development.

• Journal of Korean Society of Steel Construction
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• v.14 no.2
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• pp.365-373
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• 2002

In this paper, the system reliability concept was presented to predict the lifespan of bridges. Lifetime distribution functions (survivor functions) were used to model real bridges to predict their remaining life. Using the system reliability concept and lifetime distribution functions (survivor functions), a program called LIFETIME was developed. The survivor functions give the reliability of component at time t. The program was applied to an existing Colorado state highway bridge to predict the failure probability of the time-dependent system. The bridge was modeled as a system, with failure probability computed using time-dependent deteriorating models.