• Smart Structures and Systems
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• 제20권4호
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• pp.483-498
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• 2017

Real-Time Hybrid Simulation (RTHS) is a powerful and cost-effective dynamic experimental technique. To implement a stable and accurate RTHS, time delay present in the experiment loop needs to be compensated. This delay is mostly introduced by servo-hydraulic actuator dynamics and can be reduced by applying appropriate compensators. Existing compensators have demonstrated effective performance in achieving good tracking performance. Most of them have been focused on their application in cases where the structure under investigation is subjected to inputs with relatively low frequency bandwidth such as earthquake excitations. To advance RTHS as an attractive technique for other engineering applications with broader excitation frequency, a discrete-time feedforward compensator is developed herein via various optimization techniques to enhance the performance of RTHS. The proposed compensator is unique as a discrete-time, model-based feedforward compensator. The feedforward control is chosen because it can substantially improve the reference tracking performance and speed when the plant dynamics is well-understood and modeled. The discrete-time formulation enables the use of inherently stable digital filters for compensator development, and avoids the error induced by continuous-time to discrete-time conversion during the compensator implementation in digital computer. This paper discusses the technical challenges in designing a discrete-time compensator, and proposes several optimal solutions to resolve these challenges. The effectiveness of compensators obtained via these optimal solutions is demonstrated through both numerical and experimental studies. Then, the proposed compensators have been successfully applied to RTHS tests. By comparing these results to results obtained using several existing feedforward compensators, the proposed compensator demonstrates superior performance in both time delay and Root-Mean-Square (RMS) error.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.4112-4112
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• 2001

The feasibility of NIR spectroscopy as a quick and nondestructive method for quality control of uniformity of coating thickness of pharmaceutical tablets was investigated. Near infrared spectra of a set of pharmaceutical tablets with varying coating thickness were measured with a diffuse reflectance fiber optic probe connected to a Broker IFS 28/N FT-NIR spectrometer. The challenging issues encountered in this study included: 1. The similarity of the formulation of the core and coating materials, 2. The lack of sufficient calibration samples and 3. The non-linear relationship between the NIR spectral intensity and coating: thickness. A peak at 7184 $cm^{-1}$ was identified that differed for the coating material and the core material when M spectra were collected at 2 $cm^{-1}$ resolution (0.4 nm at 7184 $cm^{-1}$). The study showed that the coating thickness can be analyzed by polynomial fitting of the peak area of the selected peak, while least squares calibration of the same data failed due to the lack of availability of sufficient calibration samples. Samples of coal powder and solid pieces of coal were analyzed by FT-NIR diffuse reflectance spectroscopy with the goal of predicting their ash content, percentage of volatile components, and energy content. The measurements were performed on a Broker Vector 22N spectrometer with a fiber optic probe. A partial least squares model was constructed for each of the parameters of interest for solid and powdered sample forms separately. Calibration models varied in size from 4 to 10 PLS ranks. Correlation coefficients for these models ranged from 86.6 to 95.0%, with root-mean-square errors of cross validation comparable to the corresponding reference measurement methods. The use of FT-NIR diffuse reflectance measurement techniques was found to be a significant improvement over existing measurement methodologies in terms of speed and ease of use, while maintaining the desired accuracy for all parameters and sample forms.(Figure Omitted).

• Journal of Pharmaceutical Investigation
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• 제25권1호
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• pp.55-62
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• 1995

W/O and O/W emulsions of tegafur (50 mg/5 ml/kg) were orally administered to rats to compare with their mesenteric lymphatic delivery effects. And also in order to demonstrate the lymph targeting associated to the oral route, it was deemed necessary to investigate the fate of solution after oral administration as a control. Lymph and plasma samples were periodically taken from each subject of mesenteric lymphatic duct cannulated rats. Then, lymph and plasma levels of tegafur and its active metabolite, 5-FU, were simultaneously observed. Also pharmacokinetic parameters were compared with each others. On the other hand, most previous studies of lymphatic transport have not addressed the question of whether an increase in mesenteric or thoracic lymph transport by the manipulation of a suspected variable was due to a selective delivery to the intestinal lymphatics or an overall increase availability. Therefore, based on a physiologically based pharmacokinetic model which represents the characteristics of lymphatic systems, we are also going to determine the contributions of mesenteric lymph transport versus thoracic lymph transport of tegafur reported in reference(13). In comparison with tegafur solution, AUC and mean residence time of plasma tegafur were significantly increased in W/O emulsion but significantly decreased in O/W emulsion. Lymph flow rates were similar in both solution and W/O emulsion but half in O/W emulsion. AUC of tegafur in mesenteric lymph and in plasma for W/O emulsion were 3.7 times and 2.9 times more than those for O/W emulsion, respectively. And AUC of 5-FU in thoracic lymph for W/O emulsion was 3.7 times more than that for O/W emulsion. These results suggested that lymphatic delivery or tegafur by W/O emulsion was more effective than that by on emulsion due to its differences or formation ability of chylomicrons.

• 한국식생활문화학회지
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• 제35권5호
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• pp.493-502
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• 2020

The objective of this study was to investigate the effects of dietary vitamin B intake on biomarkers related to lipid metabolism, inflammation and blood glucose control, that are important in the development of type 2 diabetes and its complications. Seventy-six adults (42 males, 34 females) were recruited from a group of diabetes patients who had visited the medical center for treatment. Data on anthropometric characteristics and dietary intake of thiamine, riboflavin, niacin, vitamin B₆ and folate were collected using 24-hour diet recall and the CAN Pro 4.0 program. Also, data on clinical indices such as serum lipids, blood pressure, high-sensitivity C-reactive protein (hs-CRP), hemoglobin A1c (HbA1c) and homeostasis model assessment 2-insulin resistance (HOMA2-IR) were collected and analyzed for correlation with dietary vitamin B intake. Results from the dietary intake survey showed that riboflavin and folate intake (in males) and folate intake (in females) were below the Dietary Reference Intake for Koreans. Statistical analysis revealed a negative correlation between hs-CRP and dietary intake of B vitamins. Riboflavin intake was inversely associated with systolic blood pressure after adjustments for age, BMI, smoking, alcohol consumption, exercise, ingestion of diabetes mellitus medication and energy intake (p<0.05). Our results suggest that dietary vitamin B may influence inflammation and consequently may help in better management of type 2 diabetes.

• 서비스연구
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• 제3권2호
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• pp.1-17
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• 2013

The main purpose of this paper is to examine the aid effectiveness of ODA projects through a case of an e-Government ODA. The case at hand is the Mongolian National Data Center project, which was supported by Korea International Cooperation Agency in 2007~2009. In this paper, we analyze aid effectiveness through a case instead of a long-term macroeconomic analysis. By using OECD DAC guideline for performance evaluation of ODA project combined with PRM (Performance Reference Model) for evaluating e-Government, authors undertakes a post-implementation evaluation on the Mongolian NDC project. The result shows that the NDC project has been relevant and implemented effectively and efficiently given the political instability incurred by the election fraud in 2008. However, there have been problems as well. Provision of defected monitors was a critical problem while disagreement on the safety of the building was lasted for two more years to be settled. Some comments on the training program are also worth to hear to ameliorate similar projects. But more fundamental problems are found in impacts and sustainability areas. Low political status of ICTPA as a coordinating organization for ICT ODA and unstable job security of NDC are serious hurdles to increase effectiveness and efficiency of NDC. ICTPA has played very limited roles in coordinating government-wide ICT ODA projects because it lacks actual power and control over them. Other government organizations do not fully trust NDC as a reliable government data center due to low political status and lack of job security. Thus critical factors to affect the effectiveness and efficiency of e-Government ODA projects are political and organizational instead of economic.

• 한국수자원학회논문집
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• 제34권6호
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• pp.617-625
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• 2001

수공 방어용으로 건설된 평화의 댐은 화천댐과 연계되어 있고 배수 터널과 함께 1단계 준공 상태로서 화천댐 상류에 위치하여 댐 하류에 홍수지체 효과를 갖는다. 따라서 본 연구에서는 현 평화의 댐의 활용방안을 연구할 목적으로 화천댐 시스템 조작을 수행하여 평화의 댐 홍수조절효과와 화천댐의 홍수기 제한수위 등을 검토하고 평가하였다. 그리고 이 결과를 분석하여 화천댐 계통의 이수 증대 방안을 제시하였다. 이를 위해서 우선 저수지 조작 기준과 모형을 설정한 다음 저수지 조작의 최적화를 수행하였다. 이 결과를 바탕으로 최적치에 대한 실적치의 상대적인 값으로 조정계수를 평가하였다. 그리고 화천댐 제한수위의 몇가지 대안에 대하여 최적 저수지 조작을 수행하여 제한수위 적정 수준을 제시하고 경제적인 편익 또한 평가하였다.

• 가정과삶의질연구
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• 제24권4호
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• pp.51-73
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• 2006

The purpose of this study is to introduce the evolution of corporate family-friendly policies and programs, a recent business issue throughout the world. In addition, this study suggests implications for a corporate reference guide to work-family policies and programs by providing a comparative analysis of the typical stages of development of U.S. corporate family-friendly policies and programs, and by presenting model initiatives of Korean and American family-friendly companies. Just as technological changes at the time of the Industrial Revolution altered the relationship between workers and their work, more recent technological advances have again transformed this relationship, offering the promise of a society in which work demands a smaller portion of the worker's time and permitting the worker more freedom and control over work conditions. These new work arrangements have the promise of producing a new paradigm for work and family, based on which many industrialized nations have developed family-friendly policies already. Family-friendly policies and programs can be grouped into four discernable stages in the evolution of a corporate work-family agenda. According to these stages, most companies in Korea are in the predevelopment stage or stage 1. Development of scales to assess company family-friendliness is needed to create a family-friendly workplace environment, policies, and programs. It is critical that companies have champions who have the vision to step out in kent, and the determination to ensure that the family-friendly programs are solidly grounded. Companies should develop their work-family initiatives as an integral part of a program for managing diversity focusing on needs of women and minority employees.

• 한국터널지하공간학회 논문집
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• 제5권2호
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• pp.199-207
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• 2003

지반공학적인 측면에서의 터널에 대한 모델링작업은 실질적인 터널공사시 야기되는 상세거동을 재현할수 있는 터널장비의 개발로 터널굴진과정을 실질적으로 묘사하는데 있다고 볼수 있다. 최신기계정보활용기술은 즉 시공과정 및 기계제어기술등을 실험실에서 재현할 수 있도록 하였다. 그러나, 이러한 기술 등은 중력장상태에서 사용되도록 개발되어지고, 1g 또는 원심장 (Centrifuge Field) 상태의 실험에서 주로 활용되고 있다. 이에 따라 본 논문은 터널링과정에 대한 씨뮬레이션기법과 실험실에서 활용되는 쉴드터널장비의 설계기법 및 개발에 대한 연구 결과를 수록하였다. 또한 개발된 장비의 정밀성과 신뢰성을 반복적인 실험을 통하여 검증하고, 개발된 장비를 이용하여 얻은 결과와 실질적인 현장자료와 비교분석하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권3호
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• pp.1195-1211
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• 2016

The emerging video coding standard High Efficiency Video Coding (HEVC) has shown almost 40% bit-rate reduction over the state-of-the-art Advanced Video Coding (AVC) standard but at about 40% computational complexity overhead. The main reason for HEVC computational complexity is the inter prediction that accounts for 60%-70% of the whole encoding time. In this paper, we propose several fast coding unit (CU) encoding schemes based on the Merge mode and motion estimation information to reduce the computational complexity caused by the HEVC inter prediction. Firstly, an early Merge mode decision method based on motion estimation (EMD) is proposed for each CU size. Then, a Merge mode based early termination method (MET) is developed to determine the CU size at an early stage. To provide a better balance between computational complexity and coding efficiency, several fast CU encoding schemes are surveyed according to the rate-distortion-complexity characteristics of EMD and MET methods as a function of CU sizes. These fast CU encoding schemes can be seamlessly incorporated in the existing control structures of the HEVC encoder without limiting its potential parallelization and hardware acceleration. Experimental results demonstrate that the proposed schemes achieve 19%-46% computational complexity reduction over the HEVC test model reference software, HM 16.4, at a cost of 0.2%-2.4% bit-rate increases under the random access coding configuration. The respective values under the low-delay B coding configuration are 17%-43% and 0.1%-1.2%.

• Asian Pacific Journal of Cancer Prevention
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• 제16권13호
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• pp.5421-5425
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• 2015

To evaluate the relationship between the growth hormone 1 (GH1) T1663A polymorphism, recreational physical activity and body mass index (BMI) with reference to breast cancer, we conducted a case-control study with 669 cases of breast cancer and 682 population-based controls in Jiangsu Province, China. A structured questionnaire was used to elicit detailed information. All subjects completed an in-person interview. GH1 genotypes were identified using PCR-RFLP methods. Odds ratios (ORs) were estimated with an unconditional logistic model. The distribution of GH1 genotypes was not significantly different between controls and cases ($x^2$=2.576, P=0.276). Results of stratified analysis by the participation status of the recreational physical activity showed that the persons with GH1 A allele were at a decreased risk of breast cancer (adjusted-OR=0.66; 95% CI, 0.50-0.87) only among inactive individuals. Stratified analysis by BMI showed that the genotype A/A was associated with a decreased risk of breast cancer only among individuals of the BMI <25 (adjusted-OR=0.80; 95% CI, 0.66-0.98). The findings of this study suggest that recreational physical activity and BMI may modify any association between the GH1 T1663A polymorphism and breast cancer risk.