• Korean Journal of Materials Research
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• v.25 no.4
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• pp.196-201
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• 2015

This paper presents the impact of partial shading on $CuIn_xGa_{(1-x)}Se_2(CIGS)$ photovoltaic(PV) modules with bypass diodes. When the CIGS PV modules were partially shaded, the modules were under conditions of partial reverse bias. We investigated the characterization of the bypass diode and solar cell properties of the CIGS PV modules when these was partially shaded, comparing the results with those for a crystalline silicon module. In crystalline silicon modules, the bypass diode was operated at a partial shade modules of 1.67 % shading. This protected the crystalline silicon module from hot spot damage. In CIGS thin film modules, on the other hand, the bypass diode was not operated before 20 % shading. This caused damage because of hotspots, which occurred as wormlike defects in the CIGS thin film module. Moreover, the bypass diode adapted to the CIGS thin film module was operated fully at 60% shading, while the CIGS thin film module was not operated under these conditions. It is known that the bypass diode adapted to the CIGS thin film module operated more slowly than that of the crystalline silicon module; this bypass diode also failed to protect the module from damage. This was because of the reverse saturation current of the CIGS thin film, $1.99{\times}10^{-5}A/cm^2$, which was higher than that of crystalline silicon, $8.11{\times}10^{-7}A/cm^2$.

• Journal of Embryo Transfer
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• v.21 no.2
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• pp.129-135
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• 2006

This study was conducted to investigate the effect of in vitro maturation (IVM) duration of porcine follicular oocytes on maturation rate, polyspermic rate, and subsequent embryo development. The nuclear maturation rates of oocytes matured for 36, 38, 40, 42 and 44 hr were similar between 68.0, 78.0, 79.5, 73.8 and 81.8% respectively. There was no significant difference in the rates of polyspermy after in vitro feritilization (IVF). The cleavage rate in the group of 36 hr was significantly higher in than that of 40, 44 hr (p<0.05) but not to 38 and 42 hr. The development rate to blastocyst stage was significantly higher in the group of 38 hr (23.1%) than that in the group of 44 hr (15.6%) (p<0.05) but not to 36, 40 and 42 hr. These results suggest that the aged oocytes for 44 hr is not required for the production of bias to cysts derived from porcine IVF embryos.

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.467-485
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• 2015

The market share of private brand(PB) is growing at a rapid pace. Based on the previous studies, consumers pay more attention to the extrinsic cues when they buy the PB products. This paper proposes an integrated model to examine how the retailer credibility which is one of the important extrinsic cues affects perceived quality variation, value consciousness, attitude to PB, and PB product purchase intention. Also, familiarity with PB is regarded as a moderating variable that can interact with retailer credibility. An analysis of 199 useable questionnaires found that retailer credibility has a significant impact on the attitude to PB, directly and indirectly. Further, the moderating effect of familiarity with PB was significant. For this, we interpret that when consumers are more familiar with the private brand, they tend to have few bias toward the quality of PB. These findings provide several effective strategies for the development of PB, such that retailers must improve consumer's familiarity with PB via various promotions like free samples or testing events. Academic and practical implications of the study findings and future research directions are also discussed.

• Korean Journal of Optics and Photonics
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• v.30 no.6
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• pp.249-254
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• 2019

An optical current sensor device that measures electric current by the principle of the Faraday effect was designed and fabricated. The polarization-rotated reflection interferometer and the quadrature phase interferometer were introduced so as to improve the operational stability. Complex structures containing diverse optical components were integrated in a polymeric optical integrated circuit and manufactured in a small size. This structure allows sensing operation without extra bias feedback control, and reduces the phase change due to environmental temperature changes and vibration. However, the Verdet constant, which determines the Faraday effect, still exhibits an inherent temperature dependence. In this work, we tried to eliminate the residual temperature dependence of the optical current sensor based on polarization-rotated reflection interferometry. By varying the length of the fiber-optic wave plate, which is one of the optical components of the interferometer, we could compensate for the temperature dependence of the Verdet constant. The proposed optical current sensor exhibited measurement errors maintained within 0.2% over a temperature range, from 25℃ to 85℃.

• Korean Journal of Biological Psychiatry
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• v.17 no.2
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• pp.79-85
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• 2010

Objectives : Trauma patients have attentional bias which enforces traumatic memories and causes cognitive errors. Understanding of such selective attention may explain many aspects of the posttraumatic stress disorder(PTSD) symptoms. Methods : We used the rapid serial visual presentation(RSVP) method to verify attentional blink in burn patients with PTSD. International affective picture system(IAPS) was used as stimuli and distracters. In the 'neutral test', patients have been presented series of pictures with human face picture as target stimuli. Each picture had 100ms interval. However the distance between target facial pictures was randomized and recognition of second facial picture accuracy was measured. In the 'stress test', the first target was stress picture which arouses patient emotions instead of the facial picture. Neutral and Stress tests were done with seven PTSD patients and 20 controls. In '85ms test' the interval was reduced to 85ms. The accuracy of recognition of second target facial picture was rated in all three tests. Eighty-five ms study was done with eighteen PTSD patients. Results : Attentional blinks were observed in 100-400ms of RSVP. PTSD patients showed increased recognition rate in the 'stress test' compared with the 'neutral test'. When presentation interval was decreased to 85 ms, PTSD patient showed decrease of attentional blink effect when target facial picture interval was 170ms. Conclusion : We found attentional blink effect could be affected by stress stimulus in burn patients. And attentional blink may be affected by stimulus interval and the character of stimulus. There may be some other specific mechanism related with selective attention in attentional blink especially with facial picture processing.

• Korean Journal of Optics and Photonics
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• v.2 no.3
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• pp.139-148
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• 1991

A fiber-optic magnetic sensor system for the detection of small ac magnetic field(200Hz-2 kHz) was constructed. Magnetic field sensing part was fabricated by bonding a section of optical fiber to amorphous metallic glass(2605SC) having large magnetostriction effect. And with the directional coupler, all fiber type Mach-Zehnder interferometer was constructed to measure the variation of the external magnetic field by translating it into the optical phase shift in the interferometer. The signal fading problem of the interferometer, which is due to random phase drifts originated from the environment, i.e., temperature fluctuation, vibrations, etc., was elliminated by feedback phase compensation. This allows the sensitivity to be maintained at the maximum by keeping the interferometer in quadrature phase condition. The frequency response of metallic glass was found to be nearly flat in the range of 90 Hz-2 kHz and dc bias field for the maximum ac response was 3.5 Oe. The interferometer output showed good linearity over the range $\pm$0.5 Oe. For 1 kHz ac magnetic field the scale factor S and the minimum detectable magnetic field were measured to be 8.0 rad/Oe and $3X10^{-6} Oe/\sqrt{Hz}$at 1 Hz detection bandwidth respectively.

• The Journal of Internal Korean Medicine
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• v.41 no.3
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• pp.306-325
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• 2020

Objectives: The aim of this study is to investigate the effect of a Dachaihu decoction for hyperlipidemic acute pancreatitis (HLAP) by systematic review and meta-analysis of Chinese clinical studies. Methods: China National Knowledge Infrastructure (CNKI) was utilized as the major search engine. The date of the literature search was March 7, 2020. Randomized controlled trials (RCTs) about using a Dachaihu decoction for HLAP were included in this study. Meta-analysis was performed by synthesizing outcome data, including total effective rate, abdomen pain relief time, first bowel movement time, blood amylase recovery time, and triglyceride (TG) levels (mmol/L). The selected literature was assessed using Cochrane's risk of bias (RoB). Results: Twelve of 44 RCTs met the inclusion criteria. Most studies were evaluated with RoB as having unclear risk. The total effective rate of herbal medicine treatment based on the Dachaihu decoction was significantly higher than that of symptomatic supportive treatment in 10 articles (risk ratio=1.15, 95% CI: 1.08 to 1.21, p<0.00001, I²=0%). Herbal medicine treatment based on a Dachaihu decoction was significantly more effective than symptomatic supportive treatment in terms of reducing abdomen pain relief time (in all articles; mean difference=-1.70, 95% CI: -1.91 to -1.41, p<0.00001, I²=45%), first bowel movement time (in 7 articles; mean difference=-1.46, 95% CI: -1.86 to -1.05, p<0.00001, I²=73%), blood amylase recovery time (in 8 articles; mean difference=-1.48, 95% CI: -2.04 to -0.92, p<0.00001, I²=90%), and TG levels (in 8 articles; mean difference=-1.59, 95% CI: -2.28to -0.91, p<0.00001, I²=90%). Only one article reported side effects of treatment among the intervention group and control group, citing pancreatic ulcer and pancreatic pseudocyst formation. Conclusions: This study suggests that herbal medicine treatment based on a Dachaihu decoction could yield higher efficacy for HLAP than symptomatic supportive treatment alone. However, the results might be somewhat biased because of the poor quality and small sample size of the included RCTs. Well-qualified clinical studies are needed to prove the effectiveness of Dachaihu decoction therapy for HLAP.

• Asia pacific journal of information systems
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• v.23 no.4
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• pp.129-149
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• 2013

According to the development of new Information Technologies, firms consistently invest a significant amount of money in IT activities, such as establishing internal and external information systems. However, several anti-Information activities-such as hacking, leakage of information and system destruction-are also rapidly increasing, thus many firms are exposed to direct and indirect threats. Therefore, firms try to establish information security systems and manage these systems more effectively via an enterprise perspective. However, stakeholders or some managers have negative opinions about information security systems. Therefore, in this research, we study the relationship between multibusiness firms' performance and information security systems. Information security indicates physical and logical correspondence of information system department against threats and disaster. Studies on information security systems suggested frameworks such as IT Governance Cube and COBIT Framework to identify information security systems. Thus, this study define that information security systems is a controlled system on enterprise IT process and resource on IT Governance perspective rather than independent domain of IT. Thus, Information Security Systems should be understood as a subordinate concept of IT and business processes. In addition, this study incorporates information capability to information security system literature to show the positive relationship between Information Security Systems and Corporate Performance. The concept of information capability suggested that an interaction of human, information, technical and an effect on corporate performance using three types of capability (IT Practice, Information Management Practice, Information Behaviors and Values). Information capability is about firms' capability to manage IT infrastructure and information as well as individual employees who use IT infrastructure and information. Thus, this study uses information capability as a mediating variable for the relationship between information security systems and firms' performance. To investigate the relationship between Information Security Systems and multibusiness firms' performance, this study extends the IT relatedness concept into Information Security Systems. IT relatedness provides understanding of how corporations cope with conflicts between headquarters and business units to create a synergy effect and achieve high performance using IT resources. Based on the previous literature, this study develops the IT Security Relatedness model. IT Security Relatedness is our main independent variable, while Information Capability and Information Security Performance are mediating variables. To control for the common method bias, we collect each multibusiness firm's financial performance and use it as our dependent variable. We find that Information Security Systems influence Information Capability and Information Security Performance positively, and these two variables consequently influence Corporate Performance positively. In addition, this result indirectly shows that corporations under a multibusiness environment can obtain synergy effects using the integrated Information Security Systems. This positive impact of Information Security Systems on multibusiness firms' performance has an important implication to various stakeholders. Therefore, multibusiness firms need to establish Information Security Systems to achieve better financial performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.366-379
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• 2017

In this study, we performed a systematic review and meta-analysis to identify the effects of exercise on endothelial progenitor cells (EPCs) in patients with cardiovascular disease (CVD). We conducted database searches (Cochrane Library, PubMed, EMBASE, ScienceDirect, CINAHL, Scopus, KoreaMed, KISS, RISS, KMBASE) for the effect of exercise on cardiovascular disease, using heart disease, coronary artery disease, heart failure, cardiovascular disease, exercise, motor activity, rehabilitation, and endothelial progenitor cells as the keywords. Of the 539 studies identified, 9 met the inclusion and exclusion criteria. Comprehensive Meta-Analysis version 2.0 was used to analyze the effect size and the publication bias was checked with a funnel plot. Exercise was found to improve the VEGF (vascular endothelial growth factor), CD34+KDR+, and endothelial function, assessed via FMD (flow-mediated dilation), in the exercise vs. control groups, viz. 2.008 (95% CI 0.204-3.812), 1.399 (95% CI 0.310-2.489), and 1.881 (95% CI 0.848-2.914), respectively. Exercise improved the VEGF, number of EPCs, and endothelial function in the CVD patients. Considering the increasing prevalence and mortality rates for cardiovascular disease in Korea, the findings of this study that analyzed the effects of exercise on EPCs might provide guidelines for planning exercise interventions for patients with CVD.

• The Journal of Internal Korean Medicine
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• v.44 no.3
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• pp.387-401
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• 2023

Objective: This study was conducted to investigate the preventive effect of herbal medicines on restenosis after percutaneous coronary intervention (PCI) by reviewing randomized controlled trials (RCTs). Methods: RCTs were searched for herbal medicine treatment after PCI using eight online databases (PubMed, CNKI, Wanfang, J-STAGE, OASIS, ScienceON, KTKP, and KISS). Studies that confirmed restenosis through coronary angiography at follow-up were selected according to the inclusion and exclusion criteria. The primary outcome was the restenosis rate, and the secondary outcome was the angina recurrence rate. Data were extracted from the final selected studies according to the research methodology and then analyzed with Review Manager 5.4.1. Study quality was assessed using Cochrane's risk-of-bias (RoB) tool. Results: Of the 252 papers obtained through the primary search, nine studies that met the selection criteria were finally selected. In these nine studies, herbal medicine combined with western medicine was used for the experimental group, and western medicine treatment was used alone for the control group. The meta-analysis result revealed that the restenosis rate and angina recurrence rate were significantly lower in the experimental group than in the control group (RR=0.34, 95% CI: 0.22-0.53, p<0.00001, I²=0% and RR=0.47, 95% CI: 0.29-0.78, p=0.004, I²=0%, respectively). Furthermore, the quality of studies assessed by Cochrane's RoB was low. Conclusions: This study showed that the combined treatment of herbal medicine and western medicine was effective in preventing restenosis and angina after PCI. As the number of papers included in this study was small, a large number of high-quality clinical studies should be considered in the future.