• Smart Structures and Systems
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• 제21권3호
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• pp.287-303
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• 2018

Applications of energy harvesting from mechanical vibrations is becoming popular but the full potential of such applications is yet to be explored. This paper addresses this issue by considering an application of energy harvesting for the dual objective of serving as an indicator of structural health monitoring (SHM) and extent of control. Variation of harvested energy from an undamaged baseline is employed for this purpose and the concept is illustrated by implementing it for active vibrations of a pipe structure. Theoretical and experimental analyses are carried out to determine the energy harvesting potential from undamaged and damaged conditions. The use of energy harvesting as indicator for control is subsequently investigated, considering the effect of the introduction of a tuned mass damper (TMD). It is found that energy harvesting can be used for the detection and monitoring of the location and magnitude of damage occurring within a pipe structure. Additionally, the harvested energy acts as an indicator of the extent of reduction of vibration of pipes when a TMD is attached. This paper extends the range of applications of energy harvesting devices for the monitoring of built infrastructure and illustrates the vast potential of energy harvesters as smart sensors.

• 한국정보통신학회논문지
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• 제16권5호
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• pp.885-891
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• 2012

해상용 등명기의 동기 점멸은 해상에서 선박이 운항할 때, 다른 위험 표시기의 점등 패턴과 구분하여 선박의 안전한 운항을 지원한다. 일반적인 해상용 등명기의 점등기법은 낮과 밤을 감지하여 정해진 점등 규약에 따라 점등하는 방식으로 시간이 지남에 따라 등명기들의 시간 오차가 발생하여 등명기 전체의 동기 점멸이 이루어지지 못하고 있다. 이러한 문제를 해결하기 위하여 본 연구에서는 GPS의 위성시간을 기준으로 하여 모든 등명기들이 개별적으로 동기시간을 일정하게 맞추는 동기식 점등기법을 사용한 정전류방식의 해상용 LED 등명기를 설계하였으며, LED등명기 내부의 제한되고 밀폐된 공간에서 효율적인 방열성능을 갖는 방열방법을 제시하였다.

• 한국정보통신학회논문지
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• 제20권11호
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• pp.2067-2072
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• 2016

최근 기존 정보보호시스템을 우회하는 공격 기법의 발달로 사용자가 인식하지 못하는 형태의 정보자산에 대한 지속적인 공격으로 위협이 되고 있다. 이는 기존 시스템의 단일 대응이 어려운 APT 공격, 우회접근공격 및 암호화 패킷에 대한 공격 등에 대한 침해예측 시도에 대한 즉각적인 대응을 지원하고 공격지표 위주의 방어 전략으로 정보보호 시스템에 대한 지속적인 모니터링의 수행이 요구되고 있다. 본 논문에서는 지능형지속위협 공격경로차단을 위해 정보자산에 대한 업무영향평가를 통한 예방통제로 중요한 자산 식별하고 위험을 미리 제거하기 위하여 취약성 분석, 위험분석을 통한 정보통제 정책을 수립하고 서버접근에 대한 내 외부 우회네트워크 통제, 암호화통신 감시를 통해 탐지통제를 수립하고 백업과 복구를 통해 연계 제어된 교정통제를 하여 지능화된 침해대응 할 수 있도록 중앙집중식 지능형 정보보호시스템을 제안한다.

• 대한한방내과학회지
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• 제41권3호
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• pp.362-413
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• 2020

Objectives: The purpose of this research is to examine the recent clinical research trends on the efficiency of traditional herb medicine (THM) on gastroesophageal reflux disease (GERD), and to provide clinical evidence of herbal medicine, Banhasasin-tang or Banxiexin decoction by using a systemic review and meta-analysis of randomized trials (RCTs). Methods: In this study, randomized controlled trials (RCTs) were included that verified effects of traditional herbal medicine (THM), including a Banxia-xiexin-tang decoction, as a treatment for GERD. A study of the literature in Chinese and Korean databases was performed for papers published from January 1, 2010, to January 1, 2020. The selected literature was assessed by Cochrane's risk of bias (RoB). Results: A total of 90 RCTs met the inclusion criteria. Except for four RCT studies, all studies identified the effect of a Banxia-xiexin-tang decoction in the treatment of GERD. The effectiveness of treatment was significantly higher in the intervention group than in the control group, as shown through various evaluation indicators, including the reflux disease diagnostic questionnaire (RDQ). Adverse effects were reported in 22 articles (24.44%). Conclusions: Treatment with Banhasasin-tang, or a Banxia-xiexin-tang decoction, was found to be effective in treating GERD. However, due to the low quality of available studies, the significance of this conclusion is somewhat limited. This study could serve as a foundation for further clinical studies on the development of diagnosis and treatment methods for GERD based on Korean medicine.

• Geomechanics and Engineering
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• 제13권5호
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• pp.861-879
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• 2017

Coal and gas outburst is a serious dynamic disaster that occurs during coal mining and threatens the lives of coal miners. Currently, coal and gas outburst is commonly predicted using single indicator and its critical value. However, single indicator is unable to fully reflect all of the factors impacting outburst risk and has poor prediction accuracy. Therefore, a more accurate prediction method is necessary. In this work, we first analyzed on-site impacting factors and precursors of coal and gas outburst; then, we constructed a Fisher discriminant analysis (FDA) index system using the gas adsorption index of drilling cutting ${\Delta}h_2$, the drilling cutting weight S, the initial velocity of gas emission from borehole q, the thickness of soft coal h, and the maximum ratio of post-blasting gas emission peak to pre-blasting gas emission $B_{max}$; finally, we studied an FDA-based multiple indicators discriminant model of coal and gas outburst, and applied the discriminant model to predict coal and gas outburst. The results showed that the discriminant model has 100% prediction accuracy, even when some conventional indexes are lower than the warning criteria. The FDA method has a broad application prospects in coal and gas outburst prediction.

• Clinical Nutrition Research
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• 제5권4호
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• pp.279-289
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• 2016

The adequate dietary intake is important to maintain the nutritional status of the patients after pancreatic cancer surgery. This prospective study was designed to investigate the dietary intake and the nutritional status of the patients who had pancreatic cancer surgery. Thirty-one patients (15 men, 16 women) were enrolled and measured body weight, body mass index (BMI), nutritional risk index (NRI), and Malnutrition Universal Screening Tool (MUST). Actual oral intake with nutritional impact symptoms recorded on the clinical research foam at every meal and medical information were collected from electronic medical charts. The rates of malnutrition at admission were 45.1% (14/31) and 28.9% (9/31) by NRI and MUST method, respectively, but those were increased to 87% (27/31) and 86.6% (26/31) after operation on discharge. The median values of daily intake of energy, carbohydrates, fat, and protein were 588.1 kcal, 96.0 g, 11.8 g, and 27.0 g, respectively. Most patients (n = 20, 64.5%) experienced two or more symptoms such as anorexia, abdominal bloating and early satiety. There were negative correlations between C-reactive protein (CRP) levels and the intake of total energy, protein, fat, and zinc. The rates of malnutrition were increased sharply after surgery and the dietary intake also influenced the inflammatory indicators. The results suggested that need of considering special therapeutic diets for the patients who received pancreatic surgery.

• 보건행정학회지
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• 제29권3호
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• pp.277-287
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• 2019

Background: Diabetes is known as one of the most important ambulatory care sensitive conditions. This study purposed to assess the status of continuity of care (COC) and diabetes-related avoidable hospitalizations (DRAHs) of a group of middle- and old-aged patients and to observe the relationship of the two elements by the two age groups. Methods: This study utilized the National Health Insurance Service's National Sample Cohort data and the subjects are diabetes patients of 45 and over, classified into two groups of 'middle-aged'(45-64 years) and 'old-aged'(${\geq}65years$) patients. The dependent variable was DRAHs, which was defined in accordance with the definition of the Organization for Economic Cooperation and Development "Health Care Quality Indicators" project. COC, as an independent variable, is measured by the COC index in this study. Two-part model (multi-variate and multi-level analyses) was utilized. Results: Factors associated with the status and the number of DRAHs differed by each age group. Meanwhile, the two-part model showed that higher COC was associated with a lower risk of preventable hospitalizations in both middle- and old-aged groups. Conclusion: Study findings can provide health policy insights and implications in order to strengthen the primary care system for further improvement of diabetes management, especially for middle- and old-aged groups.

• 대한한의학방제학회지
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• 제29권4호
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• pp.285-295
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• 2021

Objective : This systematic review was conducted to investigate the effect of herbal medicine on Helicobacter pylori(H. pylori) infection compared to amoxicillin included synthetic drugs. Methods : Relevant randomized controlled trials(RCTs) which were published prior to December 26, 2020, were collected using PubMED database. Risk of bias evaluation and data extraction were done independently by two reviewers, and the third reviewer reassessed mismatching parts. Results : Two RCTs testing two different herbal medicines against synthetic drugs solitary treatment or synthetic drugs with placebo for herbal medicine were included. One study reported that there was no significant difference between the eradication rate of synthetic drugs and the herbal medicine. The other study did not report the eradication rate of the herbal medicine. One study reported histologic severity, the other reported dyspepsia score as efficacy indicators. There was no adverse event reported in all studies. However, the number of included RCTs was too small, the quality of reported data was not enough to verify efficacy of herbal medicine, and there were some methodological problems. Conclusion : It was difficult to conclude that solitary treatment of herbal medicine was as effective as amoxicillin included synthetic drugs for H. pylori infection.

• 한국환경보건학회지
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• 제47권2호
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• pp.144-154
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• 2021

Objectives: This study was intended to identify hazard contribution by region, media, and chemical by calculating a hazard-based index using pollutant release and transfer register (PRTR) data. Methods: PRTR data for the period 2011 to 2016 was analyzed to examine the regional trends in toxic releases in terms of quantity and to create a corresponding hazard-based index. For the hazard-based index, the Risk-Screening Environmental Indicators (RSEI) Model was used. Results: The results of the trend analysis show that total releases decreased slightly, but health hazard levels increased consistently. According to the outcome of regional contribution analysis of the hazard-based index, Chungcheongnam-do, Jeollabuk-do and Gyeonggi-do Provinces showed a high ratio in the index for air and water release pollutants, while Gyeongsangbuk-do and Gyeongsangnam-do Provinces showed a high ratio in the index of soil release and waste transfer pollutants. Also, as a result of the analysis of the top ranked substances in the hazard-based index, it was found that chromium, cobalt and its compounds, and ethylene oxide contributed greatly to air release substances, while chromium, benzene, and lead and its compounds contributed greatly to water release substances. Conclusion: These results showed considerable disparities between total release and health hazard levels, especially in the analysis of contribution by regions and by chemical substance. Therefore, the hazard-based index should be used both to support a more comprehensive and robust approach to screening of chemicals for environmental health policy and for management.

• Safety and Health at Work
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• 제9권4호
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• pp.454-461
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• 2018

Background: Working conditions and psychosocial work factors have acquired an important role explaining the well-being and performance of professional drivers, including those working in the field of public transport. This study aimed to examine the association between job strain and the operational performance of public transport drivers and to compare the expositions with psychosocial risk at work of three different types of transport workers: taxi drivers, city bus drivers, and interurban bus drivers. Method: A sample of 780 professional drivers was drawn from three transport companies in Bogota (Colombia). The participants answered the Job Content Questionnaire and a set of sociodemographic and driving performance questions, including age, professional driving experience, work schedules, and accidents and penalties suffered in the last 2 years. Results: Analyses showed significant associations between measures of socio-labor variables and key performance indicators such road traffic accidents and penalties. Furthermore, multiple linear regression analysis contributed to explain significantly suffered accidents from key variables of the Job Demand-Control model, essentially from job strain. In addition, throughout post-hoc analyses, significant differences were found in terms of perceived social support, job strain, and job insecurity. Conclusion: Work stress is an issue that compromises the safety of professional drivers. This research provides evidence supporting a significant effect of job strain on the professional driver's performance. Moreover, the statistically significant differences between taxi drivers, city bus drivers, and interurban bus drivers in their expositions to work-related stress suggest the need for tailored occupational safety interventions on each occupational group.