• 한국문헌정보학회지
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• 제49권2호
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• pp.27-49
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• 2015

The purpose of this study is to suggest an appropriate index for evaluating preferences of Web contents by examining the h-index and its variants. It focuses on how successfully each index represents relative user preference towards topical subjects. Based on data obtained from a popular IT blog (engadget.com), subject values of the h-index and its variants were calculated using 53 subject categories, article counts and the 'Likes' counts aggregated in each category. These values were compared through critical analysis of the indices and Spearman rank correlation analysis. A PFNet (Pathfinder Network) of subjects weighted by $h_T$ values was drawn and cluster analysis was conducted. Based on the four criteria suggested for the evaluation of Web contents, we concluded that the $h_T$-index is a relatively appropriate tool for the Web contents preference evaluation. The $h_T$-index was applied to visually represent the relative weight (topic preference by user 'Likes' count) for each subject category of the real online contents after suggesting the relative appropriateness of the $h_T$-index. Applying scientometric indicators to Web information could provide new insights into, and potential methods for, Web contents evaluation. In addition, information on the focus of users' attention would help online informants to plan more effective content strategies. The study tries to expand the application area of the h-type indices to non-academic online environments. The research procedure enables examination of the appropriateness of the index and highlights considerations for applying the indicators to Web contents.

• 대한기계학회논문집B
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• 제30권10호
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• pp.973-981
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• 2006

Recently there is an increasing interest in particulate matter emission because of new emission regulations, health awareness and environmental problems. It requires to improve particulate measurement techniques as well as to reduce soot emissions from combustion systems. As mentioned above, it is demanded that reduction techniques together with measurement techniques of exhausted particulate matters in combustion systems such as vehicles. However, measurement techniques of particulate matters should be prior to reduction techniques of that because it is able to know an increase and a decrease of exhausted particulate matters when measured particulate matters. Therefore, in this study, we report the measurement of soot primary-particle size using time-resolved laser induced incandescence (TIRE-LII) technique in laminar ethylene diffusion flame. As an optical method, laser induced incandescence is one of well known methods to get information for spatial and temporal soot volume fraction and soot primary particle size. Furthermore, TIRE-LII is able to measure soot primary particle size that is decided to solve the decay ate of signal S $(t_1)$ and S $(t_2)$ at two detection time. In laminar ethylene diffusion flame, visual flame height is 40 mm from burner tip and measurement points are height of 15, 20, 27.5, 30 mm above burner tip along radial direction. As increasing the height of the flame from burne. tip, primary particle size was increased to HAB(Height Above Burner tip)=20mm, and then decreased from HAB=27.5 mm to 30 mm. This results show the growth and oxidation processes for soot particles formed by combustion.

• Nuclear Engineering and Technology
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• 제56권2호
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• pp.402-409
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• 2024

High energy neutron irradiations impact on structural and electrical properties of alumina are studied with particular emphasis on real time in-situ radiation induced conductivity measurement in low flux region. Polycrystalline Al₂O₃ samples are subjected to high energy neutrons produced from D-T neutron generator and Am-Be neutron source. 14 MeV neutrons from D-T generator are chosen to study the role of fast neutron irradiation in the structural modification of samples. Real time in-situ electrical measurement is performed to investigate the change in insulation resistance of Al₂O₃ due to radiation induced conductivity at low flux regime. During neutron irradiation, a significant transient decrease in insulation resistance is observed which recovers relative higher value just after neutron exposure is switched off. XRD results of 14 MeV neutron irradiated samples suggest annealing effect. Impact of relatively low energy neutrons on the structural properties is also studied using Am-Be neutrons. In this case, clustering is observed on the sample surface after prolonged neutron exposure. The structural characterizations of pristine and irradiated Al₂O₃ samples are performed using XRD, SEM, and EDX. The results from these characterizations are analysed and interpreted in the manuscript.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제42권
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• pp.11.1-11.8
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• 2020

Background: The purpose of this study is to compare the skeletal stability of two-jaw surgery via surgery-first approach with conventional two-jaw surgery in facial asymmetry patients by measuring the skeletal changes after surgery from a three-dimensional analysis. From January 2010 to January 2014, 40 patients with facial asymmetry who underwent two-jaw surgery in Pusan National University Hospital were included in this study. They were classified into experimental group (n = 20) who underwent two-jaw surgery via surgery-first approach and control group (n = 20) who underwent conventional two-jaw surgery. After selection of 24 landmarks and the construction of horizontal and sagittal, coronal reference planes, changes in 10 linear measurements and 2 angular measurements were compared between the surgery-first approach and conventional groups in the preoperative, immediate postoperative, and postoperative periods. The paired t test and Student t test were used for statistical analysis. The mean and standard deviation of the measurement were calculated for the experimental and control groups. Results: The statistical analysis showed that changes in skeletal measurements were similar between the surgery-first approach and conventional groups, according to each period. However, U1-SRP measurement showed statistically significant changes in surgery-first approach groups at postsurgical change (T1 to T2). Also, the mean treatment duration in the treatment group was 15.9 ± 5.48 months whereas that in the control group was 32.9 ± 14.05 months. Conclusion: In facial asymmetry patients, similar results were observed in the postoperative skeletal stability when 2-jaw surgery via surgery-first approach was compared with conventional 2-jaw surgery. However, significant lateral deviation of upper incisor midline was observed. In addition, a shorter average treatment duration was observed. To stabilize the unstable occlusion after surgery, increased wearing of the stent and proactive rubber guidance will be needed.

• Journal of Ecology and Environment
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• 제29권5호
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• pp.485-488
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• 2006

Allometric equations for biomass measurement of the shrub species, Lindera obtusiloba, were developed. The allometric equations between $(BD)^2H$ and dry weight of leaves ($W_I$), stems and branches ($W_{sb}$), roots ($W_r$) and total weight ($W_t$) of the Lindera obtusiloba were as follows: $W_I=0.7318\;(BD^2H)^{0.6108},\;W_{sb}=0.6067(BD^2H)^{0.8355},\;W_r=0.4524(BD^2H)^{0.7608},\;W_t=1.672 (BD^2H)^{0.7664}$. The $R^2s$ between $(BD)^2H\;and\;W_I,\;W_{sb},\;W_r\;and\;W_t$ of the Lindera obtusiloba were 0.9251, 0.9571, 0.9353 and 0.9546, respectively. Root weight of this Lindera obtusiloba was about 38% of the aboveground biomass.

• 센서학회지
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• 제7권6호
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• pp.401-408
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• 1998

교류전압표준기인 열전형 전압변환기의 교류-직류 변환오차를 비교평가하기 위하여 이중채널방식 자동측정시스템을 개발하였다. 비교측정되는 2대의 변환기출력을 동시에 측정하여 드리프트의 영향을 감소시켰고, 또 저열기전력 이중채널 스캐너를 사용하여 변환기 출력을 순방향-역방향으로 측정하여 그 평균값을 취함으로서 전압측정기의 ���V전압이 제거되도록 하였다. 정격전압이 동일한 4 V인 변환기끼리 비교 측정한 결과, 주파수 $40\;Hz{\sim}100\;kHz$에서는 외국표준기관에서의 측정값과 약 ${\pm}2\;ppm$ 이내에서 일치하였으며, $200\;kHz{\sim}1\;MHz$ 범위에서는 약 ${\pm}4\;ppm$ 이내에서 일치하였다. 본 시스템의 개발로 변환기의 교류-직류 변환오차의 측정능력을 기존수동방식의 약 ${\pm}15\;ppm$에서 ${\pm}\;3ppm$(100 kHz 이하)로 크게 향상시켰으며, 표준유지 및 산업체 지원의 효율을 크게 높일 수 있게 되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.353-354
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• 2008

• Journal of Biosystems Engineering
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• 제16권1호
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• pp.1-8
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• 1991

This study was carried out to evaluate indirect methods of engine torque measurement. Three indirect methods based on throttle valve opening, exhaust gas temperature and inlet air pressure were compared. The indirect method based on throttle valve opening appeared to be the most satisfactory in terms of accuracy and response time. The discrepancies between the direct method and the indirect method based on throttle valve opening in measuring engine torque were 2% on t he average.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2007년도 The 1st International Symposium on Advanced Magnetic Materials
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• pp.239.2-239.2
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• 2007

• Journal of Biosystems Engineering
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• 제13권4호
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• pp.46-55
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• 1988

The objective of this study was to develop a computer measurement and control system which enable it possible to manage the natural air rough rice drying and storage properly and safely. The following contents of work were taken in this study in order to fulfill the above goal: 1) Design and construction of measurement system which can measure the rough rice drying conditions automatically and transfer them to computer system for data processing. 2) Development of a management software which can determine the need of fan operation by the analysis of drying and/or storage conditions. 3) Design and construction of a control system which deliver the computer decision of fan operation and make it on and off. 4) Technical and economical analysis of the computer measurement and control system development by the comparison experiments of the computer management and of the manual.