• Journal of the Korean Society of Safety
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• v.34 no.1
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• pp.14-20
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• 2019

This paper presents a safety assessment based approach for the safe operation for PCS(Power Conditioning System) of photovoltaic and energy storage systems, applying FTA. The approach established top events as power outage and a failure likely to cause the largest damage among the potential risks of PCS. Then the Minimal Cut Set (MCS) and the importance of basic events were analyzed for implementing risk assessment. To cope with the objects, the components and their functions of PCS were categorized. To calculate the MCS frequency based on IEEE J Photovolt 2013, IEEE Std. 493-2007 and RAC (EPRD, NPRD), the failure rate and failure mode were produced regarding the basic events. In order to analyze the top event of failure and power outage, it was assumed that failures occurred in DC breaker, AC breaker, SMPS, DC filter, Inverter, CT, PT, DSP board, HMI, AC reactor, MC and EMI filter and Fault Tree was drawn. It is expected that the MCS and the importance of basic event resulting from this study will help find and remove the causes of failure and power outage in PCS for efficient safety management.

• The Korean Journal of Health Service Management
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• v.4 no.1
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• pp.145-156
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• 2010

The purpose of this study is one of high price medical equipment wished to grasp propriety factor about the MRI introduction, analyzing payability through cost accounting into compensation. It was investigated from January 1 to December 31, 2007 about the MRI of a General Hospital. Expectation availability was 23.2 cases, but actual availability did achievement more than 196.1% with 45.5 items. It is estimated that there are a lot of occurrence cases because great reasons that actual availability increases more than expectation availability is excellent resolving power than a CT, and is device that prefer to reason back that radiation damage is less in person body. The followings show the main results of this study. 1. The MRI was construed in order of cost accounting, wave and personnel expenses 45.4%, administrative expenses 53.0%, and material costs 1.6%. 2. According to CVP (Cost-volume-profit) analysis, BEP (Break Even Point) profit is 173,931,428 won for 11 months, and break even usage number of items are 37.5 cases, and separation usage number of items were confirmed by 1.4 cases. Therefore, was construed that can achieve BEP within 11 months though usage number of items keeps 1.4 items day to create the MRI's hospital operation profit. 3. Estimated limit profitability appears high by 96.7%, exceed fixed charges even if when is non-benefit and when it is benefit consider variable, is judged that the MRI's addition induction helps in hospital management enhancing earning rates.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.2
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• pp.137-145
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• 2014

Objectives: The study examines the relation between urinary arsenic concentration and blood pressure, which is a risk factor of cardiovascular disease. Materials: In this study, the urinary arsenic concentration, history of diagnosed disease, and blood pressure of 782 local residents in Gwangyang, Yeosu, and Hadong regions from May 2007 to July 2007. Results: The urinary arsenic concentration of total participants was $9.06{\mu}g/g-ct$. The logistic regression analysis of medical diagnosed history and urinary arsenic concentration, showed statistically significance (p<0.05) of high urinary arsenic concentration in participants with diagnosed hypertension. In addition, diagnosed hypertension it was observed that the high blood pressure was related with the pulse pressure. Conclusions: The arsenic concentration level was low in this study, but the exposure to low levels of arsenic has an effect on hypertension. Also, hypertension is related to pulse pressure and mean arterial blood pressure as well as being risk factor of cardiovascular disease. Therefore, close supervision of low -level arsenic exposure is needed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.521-522
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• 2008

21세기를 접하면서 산업전자 분야의 비약적인 발전과 함께 과학문명은 눈부시게 발전해 나아가고 있다. 이것의 원천은 바로 전기(Electric)이다. 우리는 풍요로운 삶 자체를 전기 공급에서 누리고 있으며 또 비극적인 사태를 맞이할 때도 있다. 즉, 전기기기를 이용하면 원하건 원치 않건 전자기파가 발생이 된다 이것이 자연현상이며 전자기파는 IT, BT, CT를 비롯하여 산업 전체에 많은 영향을 미치고 있다. 일반적으로 우리가 말하는 전자기파 장해의 기본 요소는 노이즈원(잡음원), 경로매체, 피해장치 등으로 구성되는 데 잡음원(Noise Source)은 각종 시스템에서 구성되고 있는 전자기 에너지의 발생원으로 볼 수 있으며 이 발생원에서 경로매체(금속:전도성, 대기중:전파성 등)를 통하여 피해장치(전기전자통신기기류)에 방해를 주고 있는 상태를 전자기파 장해라고 설명할 수 있다. 전자기파 잡음원에서 경로를 거쳐 전자기파에 대하여 피해장치가 안정된 상태로 동작하도록 규정하는 용어 즉, 전자파 양립성 또는 적합성 (EMC : Electro Magnetic Compatibility))이란 용어를 가지고 전기 전자 통신기기에서 발생되는 불필요한 전자파와 전자파 내성시험을 만족하도록 의무화하고 있다. EMC 는 EMI (불요 전자파 또는 전자파 간섭 : Electro Magnetic Interference) + EMS (전자파 내성 : Electro Magnetic Susceptibility) 2가지 시험을 함께 전자파 적합성 (EMC) 시험으로 표현되고 있다. 전자파 적합성 시험의 목적으로 EMl는 전도성 또는 전파성에 대한 주파수 대역(잡음)을 보호하기 위한 것이 목적이고 EMS는 프로세서가 내장된 기기류의 오동작을 방지하기 위하여 감응평가를 하는 것이다. 즉, 감응(Susceptibility)이란 어떤 장비나 시스템이 전자기파 장해에 쉽게 영향을 받는 것을 뜻하는 데 전자파 장해를 견디면서 본래의 기능을 충분하게 발휘하며 동작할 수 있는 능력을 말한다.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.1
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• pp.61-72
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• 2012

Background: The purpose of this study was to analyze the associations between physical therapists' work-related musculoskeletal pain, quality of life (QoL), and presenteeism. Methods: Self-reported questionnaires were given to 402 physical therapists in Korea. Variables examined included the prevalence of pain sites related to work, pain intensity, pain pattern, pain frequency, pain duration, pain rating score (PRS), general characteristics, QoL, and presenteeism. Results: Of the 314 physical therapists who responded, 251 (79.9%) reported work -related musculoskeletal pain in at least one body part. The most affected regions included the wrist and hand (21.0%), shoulder (19.6%), and lower back (19.1%). On average patients, QoL and presenteeism differed significantly between physical therapists who reported pain and those who did not (P < 0.05). QoL showed a negative correlation with the work-related musculoskeletal pain (P < 0.01) and presenteeism (P < 0.01), while the presenteeism and work-related musculoskeletal pain showed positive one(P < 0.01). Factors influencing a physical therapist's QoL included presenteeism, Working venues (Convalescent hospital), Work status (Contra ct worker) and professional experience, while the presenteeism included QoL, work status (Intern), PRS, working venues (Convalescent hospital), Area of specialty (Pediatrics), age, sex and working hour. Conclusions: Results show that physical therapists appear to be at a higher risk for work-related musculoskeletal pain. Therefore, administrators need to use the intervention strategies to manage the presenteeism and QoL of physical therapists.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.5
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• pp.597-608
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• 2021

The control head components used in small military vessels are designed to be domestically produced, prototypes, structural analysis, and casting methods are designed and cast. The control head assembly consists of a lever, an aluminum outside cover, Middle, front gear cover, back gear cover, and a zinc worm gear. In order to reverse the design of each component, 3D scanning device was used, 3D modeling was performed by CATIA, and prototype productions were carried out by 3D printer. In order to reduce the cost of components, gating system is used by gravity casting method. The SRG ratio of 1:0.9:0.6 was set by applying non-pressurized gating system to aluminum parts, 1:2.2:2.0 and pressurized gating system to zinc parts, and the shapes of sprue, runner and gate were designed. The results of porosity were also confirmed by casting analysis in order to determine whether the appropriate gating system can be designed. The results showed that all parts started solidification after filling completely. ANSYS was used for structural analysis, and the results confirmed that all five components had a safety factor of 15 more. All castings are free of defects in appearance, and CT results show only very small porosity. ZnDC1 zinc alloy worm gear has a tensile strength of 285 MPa and an elongation of 8%. The tensile strength of the four components of A356 aluminum alloy is about 137-162 MPa and the elongation is 4.8-6.5%.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.5
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• pp.589-596
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• 2021

In this study, the optimum gating system was designed, and the two zinc alloy worm gears were manufactured in single process by applying a symmetrical gating system with 2 runners. The SRG ratio is set to 1 : 0.9 : 0.6, and the cross-sectional shapes such as sprue, runner and gate are designed. In order to determine whether the design of the gating system is appropriate, casting analysis was carried out. It takes 4.380 s to charge the casting 100%, 0.55 to 0.6 m/s at the gates and solidification begins after the casting is fully charged. The amount of air entrapment is 2% in the left gear and 6% in the right gear. Hot spots occurred in the center hole of the gear, and pores were found to occur around the upper part of the hole. Therefore, the design of the casting method is suitable for worm gears. CT analysis showed that all parts of worm gear were distributed with fine pores and some coarse pores were distributed around the central hole of worm gear. The yield strength and tensile strength were 220 MPa, 285 MPa, and the elongation rate was 8%. Vickers hardness is 82 HV.

• Applied Chemistry for Engineering
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• v.22 no.1
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• pp.91-97
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• 2011

The efficacies of anti-atopic preparations were investigated in hairless mice suffering from 2,4-dinitro-chlorobenzene (DNCB)-induced atopic dermatitis-like lesion. Solid lipid nanoparticle (SLN) containing ceramide and astaxanthin was prepared by a melt-homogenization method using Aminsoft-CT 12 (Cocoyl glutamate) as an emulsifier. And then, the SLNs were coated with silk fibroin (SF) by taking advantage of an electrostatic interaction between the surface of SLNs and SF. SLNs were included in lotion (FL) and cream (FC) types of preparations. Anti-atopic efficacies of the preparations were investigated in terms of appearance of skin surface, spleen index, serum IgE level, and serum cytokine level. SLN-containing preparations suppressed IgE production and IL-4 expression, but promoted $IFN-{\gamma}$ expression.

• The Journal of the Korea Contents Association
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• v.22 no.5
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• pp.383-392
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• 2022

Culture technology is contributing to the creation of new values through convergence with other industries. The government is also actively investing in R&D in this field to secure competitiveness. In this study, the R&D efficiency of culture technology is analyzed by characteristics. Data envelopment analysis and non-parametric tests are performed on 968 national research projects in 2016-2019. As a result, it is confirmed that there are a difference in R&D efficiency according to the characteristics of national research projects in culture technology sector. This suggests that when planning national research projects for culture technology, these characteristics should be taken into consideration and strategically promoted.

• Review of Culture and Economy
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• v.17 no.2
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• pp.103-135
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• 2014

This research dwells on the new paradigm of policy making of some innovative nations in Korean content industry. Especially this paper did evaluation of governmental policy in recent 5 years (2008~2012) in the field of Korean content industry. According to this research, the program of policy in Korean content industry had been obsessed to passive enrichment focusing on some part of content industry. The whole process of policy, scheme of policy and working flow of policy were very constrained in order to encourage more measurable area like CT(culture technology). Thus, we need new strong policy in this new government launched in 2013. The apparent keyword should be 'management'. New activity of policy need to focus on encourage Korean content industry in the real site of field, not in bureaucratic office in remote site. This change reflecting real filed management system would be productive innovation for policy making and activity in Korea.