• 전력전자학회논문지
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• 제7권4호
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• pp.346-352
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• 2002

본 논문에서는 정류용 다이오드의 역 회복시 발생하는 손실을 줄이기 위한 새로운 듀얼 모드로 동작하는 ZCS-PWM 승압형 컨버터를 제안한다 제안된 회로에서 각각의 스위치는 소프트 스위칭 조건에서 매 사이클마다 교번으로 스위칭 동작을 하고 스위치 $S_2$에 직렬로 공진형 인덕터 Lr을 달아서 스위칭 손실과 EMI 노이즈와 관련된 정류용 다이오드$(D, D_1)$의 역 회복 전류를 감소시켰다. 제안된 컨버터는 기존의 ZVT-PWM 컨버터$^{[2]}$에 수동 및 능동 소자를 더 이상 추가하지 않기 때문에 각 소자들이 받는 전류/전압 스트레스는 기존의 하드 스위칭 컨버터 같다. 본 논문에서는 제안된 회로의 동작을 분석하고 이를 바탕으로 제작 및 실험을 통해서 타당성을 입증하였다.

• 방사성폐기물학회지
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• 제14권4호
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• pp.435-443
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• 2016

본 논문은 국내 원전의 습식저장조에 저장 중인 경수로형 사용후핵연료를 금속겸용용기를 이용해 건식으로 운영하기 위한 운영공정을 개발하는 것이다. 국내 경수로형 원전의 사용후핵연료는 1990년대 초부터 습식으로 소내에서 운반을 한 경험은 많으나 건식으로 운전한 경험은 전혀 없는 실정이다. 이에 따라 금속겸용용기를 운영할 수 있는 세부 운영공정을 개발하였으며 주요 운영공정에서 금속겸용용기의 주요 구성품 및 사용후핵연료의 안전성이 유지됨을 확인하였다. 단기운영공정은 총 21시간 내에 이루어지도록 절차를 수립하였고 단계별로 허용운전 시간(15시간 습식공정, 3시간 배수공정, 그리고 3시간 진공공정)도 제시하였다.

• 가정과삶의질연구
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• 제33권4호
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• pp.1-17
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• 2015

The purpose of this study was to investigate the effects of individual characteristics, family characteristics, job characteristics, and family strength on work-family spillover in dual-earner families focusing on users and non-user of Healthy Family Support Centers(HFSC). The subjects were 703 people who lived in Seoul and Gyeonggi-Do. The results were analyzed by using the PASW 21.0 program. The findings of this study led to the following conclusions: First, the users of HFSC showed a higher level of family strength than the non-users did. This is the users had a high level of awareness of family's values and importance compared to the non-users. Second, the users revealed higher levels at a positive spillover from work to family and from family to work than the non-users. Therefore, it is confirmed that the users have a positive view of work-family spillover due to their family strength. Finally, there was a significant result at the moderation effects of work-family spillover according to personal traits, family and job characteristics. Specifically, work-family negative spillover was effected family strength through the age of the users' children. The result suggest that family strength has positive effects on the family cycle. It will be worthwhile to pay attention in future research to discover what is the appropriate support for dual earner families.

• International Journal of Advanced Culture Technology
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• 제7권1호
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• pp.231-236
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• 2019

Background/Objectives: This paper proposes a dual mode feedback-controlled cycling system for children with spastic cerebral palsy to rehabilitate upper extremities. Repetitive upper limb exercise in this therapy aims to both reduce and analyze the abnormal torque patterns of arm movements in three- dimensional space. Methods/Statistical analysis: We designed an exercycle robot which consists of a BLDC motor, a torque sensor, a bevel gear and bearings. Mechanical structures are customized for children of age between 7~13 years old and induces reaching and pulling task in a symmetric circulation. The shafts and external frames were designed and printed using 3D printer. While the child performs active/passive exercise, angular position, angular velocity, and relative torque of the pedal shaft are measured and displayed in real time. Findings: Experiment was designed to observe the features of a cerebral palsy child's exercise. Two children with bilateral spastic cerebral palsy participated in the experiment and conducted an active exercise at normal speed for 3 sets, 15 seconds for each. As the pedal reached 90 degrees and 270 degrees, the subject showed minimum torque, in which the child showed difficulty in the pulling task of the cycle. The passive exercise assisted the child to maintain a relatively constant torque while visually observing the movement patterns. Using two types of exercise enabled the child to overcome the abnormal torque measured in the active data by performing the passive exercise. Thus, this system has advantage not only in allowing the child to perform the difficult task, which may contribute in improving the muscle strength and endurance and reducing the spasticity but also provide customizable system according to the child's motion characteristic. Improvements/Applications: Further study is needed to observe how passive exercise influences the movement characteristics of an active motion and how customized experiment settings can optimize the effect of pediatric rehabilitation for spastic cerebral palsy.

• Journal of Power Electronics
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• 제10권5호
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• pp.451-460
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• 2010

This paper presents a new kind of digital control metal halide lamp electronic ballast. A zero-voltage-switch quasi-square-wave (ZVS-QSW) dual Buck converter is adopted here. In this paper, a digital control method is proposed to achieve ZVS for the converter. This ZVS can be realized during the whole working condition. Single-cycle-peak-current control is proposed to solve the problem of excessive inductor current during a low-frequency reversal transient. Power loop control is also realized and its consistency for different lamps is good. An AVR special microcontroller for a HID ballast is used to raise the control performance, and the low-frequency square-wave control method is adopted to avoid acoustic resonance. A 70W prototype was built in the laboratory. Experimental results show that the electronic ballast works reliably. Furthermore, the efficiency of the ballast can be higher than 92%.

• Toxicological Research
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• 제17권
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• pp.59-69
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• 2001

Arsenic exposure is associated with several human diseases, including cancers, atherosclerosis, hypertension, and cerebrovascular diseases. In cultured cells, arsenite, an inorganic arsenic com-pound, was demonstrated to interfere with many physiological functions, such as enhancement of oxidative stress, delay of cell cycle progression, and induction of structural and numerical changes of chromosomes. The objective of this study is to investigate the effects of arsenic exposure on gene expression profiles by colorimetric cDNA microarray technique. HFW (normal human diploid skin fibroblasts), CL3 (human lung adenocarcinoma cell line), and HaCaT (immortalized human keratinocyte cell line) were treated with 5 $\mu\textrm{M}$ or 10 $\mu\textrm{M}$ sodium arsenite for 6 or 16 h, respectively. By a dual-color detection system, the expression profile of arsenite-treated cultures was compared to that of control cultures. Several genes expressed differentially were identified on the microarray membranes. For example, MDM2, SWI/SNF, ubiquitin specific protease 4, MAP3K11, RecQ protein-like 5, and Ribosomal protein Ll0a were consistently induced in all three cell types by arsenite, whereas prohibitin, cyclin D1, nucleolar protein 1, PCNA, Nm23, and immediate early protein (ETR101) were apparently inhibited. The present results suggest that arsenite insults altered the expression of several genes participating in cellular responses to DNA damage, stress, transcription, and cell cycle arrest.

• 대한의생명과학회지
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• 제23권3호
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• pp.290-294
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• 2017

Metformin or sodium salicylate is known to induce apoptosis and G0/G1 phase arrest in a variety of cancer cells. However, the anti-cancer effects of the combined treatments for these drugs-induced apoptosis are yet unclear. Here, we found that the combined treatment of metformin and sodium salicylate increased the efficacy of chemotherapeutics against breast cancer cells. These combined drugs significantly inhibited cellular proliferation and induced apoptosis at an earlier stage in human MCF-7 breast cancer cells. Also, co-treatments of metformin and sodium salicylate induced G1 cell cycle arrest in MCF-7 cells more effectively than either agent alone. Taken together, these results demonstrate that dual metformin/sodium salicylate treatment prevents proliferation of MCF-7 cells by inducing apoptosis and G1 cell cycle arrest.

• 대한기계학회논문집
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• 제12권4호
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• pp.747-754
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• 1988

본 연구에서는 우리나라 자동차업계에서 널리 사용되는 복합조직인 고장력 강 판(high strength steel sheet, HS)과 아연도금강판(galvanized steel sheet, GA)을 선택하여 각 강판간의 점용접 피로특성을 규명하기 위하여 아래와 같은 4가지 조건하 의 단점 점용접 시험편을 제작하였다.

• Animal cells and systems
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• 제2권4호
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• pp.529-538
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• 1998

In order to analyze the intracellu1ar localization of specific RNA components of ribonucleoproteins (RNP) in Xenopus oocytes, a modified protocol of whole-mount in situ Hybridization is presented in this paper, Mitochondria specific 12S rRNA probe was used to detect the amplification and distribution of mitochondria in various stages of the oocyte life cycle, and the results were found to be consistent with previously known distribution of mitochondria. The results with other specific probes (U1 and U3 small nuclear RNAs, and 5S RNA) also indicate that this procedure is generally effective in localizing RNAs in RNP complexes even inside organelles. In addition, the RNA component of RNase MRP, the RNP with endoribo-nuclease activity, localize to the nucleus in various stages of the oocyte life cycle. Some of MRP RNA, however, were found to be localized to the special population of mitochondria near the nucleus, especially in the active stage of mitochondrial amplification. It suggests dual localization of RNase MRP in the nucleus and mitochondria, which is consistent with the proposed roles of RNase MRP in mitochondrial DNA replication and in rRNA processing in the nucleolus.

• 대한가정학회지
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• 제35권5호
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• pp.1.1-15
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• 1997

The purposes of this study were to identify the household's financial status by life cycle stage and no analyze contributing factors to financial planning for retirement preparation among Korean marred couples. For these purpose, 2074 married couples those being under 55 and having either single earner or dual earners were selected, and total sample was divided into three stages; young-aged(＜35), middle-aged(35-44) & old-aged(45-54). Statistics were frequencies, means, percentile, and logistic analysis. The results were as follows. First, old-aged had higher level of total income, total expenditure and total assets than either young-aged or middle-aged. In addition, households those holding private pensions were likely to have higher total income, total expenditure and total assets than those owning no private pension. while middle-aged had a highest total debts. Second, gini coefficients of total income and total expenditure between three aged groups were similar, but old-aged had the highest gini coefficient of total assets and total debts. In particular, gini coefficients of total assets and total debts of households those having no private pension were greater than those holding private pensions. third, contributing factors to private pension ownership of young-aged were family & household-related factor and financial factor, middle-aged's factors were household head's characteristics and financial factor. Also, old-aged's factors were household head's characteristics, family & household-related factor and financial factor.