• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.6
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• pp.96-101
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• 2020

In this paper, we present the results of our research to perform 3D laser scanning functions by adding a focusing lens to a conventional 2D laser scanner. For the optical design, the ray-tracing technique was used along with a total of four lenses as the variable incident focusing lens, the collimating lens, and the F-Theta lens. As design variables, the curvature of the incident focusing lens (Lens #1) was assumed to be us, l mm and sumed mm, and the incident angles were set at 0cidenus, l. In addition, the distance between the focusing lens and the collimating lens was set to vary from 5 mm to 15 mm. When the incident focal length was varied from 5 mm to 15 mm, the exit focal length was calculated to vary from 67.5 mm to 56.8 mm for the lens with R = 100 mm and from 108.5 mm to 99.0 mm for the lens with R = 150 mm. When the incident angle was 0°, the focal aberration was only slightly observable at 10㎛ in both the x- and y-direction. At 7.5° was the focal aberration of approximately 20~50㎛ was measured at 20㎛. To investigate the chromatic aberration of the designed optical device, the distortion of the focus was observed when the 550 nm beam was simulated on lens designed for a 980 nm wavelength.

• Journal of radiological science and technology
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• v.16 no.1
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• pp.101-106
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• 1993

In order to assure safety of both patient and operator, and to provide uniform quality radiographs, it is necessary to perform periodic calibration of diagnostic X-ray equipment. A basic parameter of diagnostic equipment's and its image sharpness is the size(and shape the energy distribution) of the focal spot as viewed along the central X-ray beam. This size determines the resolution possible with the equipment and also determines the heat characteristics of an anode. A fine focus tube gives high resolution but causes high local heating of target. In past, the pin-hole and star pattern image measurement for evaluation of resolution have been widely used, but it produced blurring and inaccuracy of image. So newly inverted Ug-meter has advantage in more convenient measurement method and less out-put bias than other image measurement. The authors intended to compare measured focal size between Ug-meter and focal spot test tool, changed state from setting to now of units.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1777-1783
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• 2004

This study was conducted to determine the effects Wonjiseokchangpo-san on brain damage in transient focal cerebral ischemia. Rats were used for testing in the following three models: Morris Water Maze, Eight-Arm Radial Maze, and Histochemistry. In the Morris Water Maze Model, the Wonjiseokchangpo-san group showed significant decrease in the 3rd and 6th training session compared with the ischemia group. A retention test, in the Morris Water Maze Model, was performed on the 7th day without the escape platform. The Wonjiseokchangpo-san group showed significant increase compared to the ischemia group. In the Eight-Arm radial Maze model, the Wonjiseokchangpo-san group showed significant decrease in the error rate compared to the ischemia group. In the density of hippocampal CA1 cell of the cresyl violet-stained section, the Wonjiseokahangpo-san group showed significant increase compared to the ischemia group. These results suggest that Wonjiseokchangpo-san may have a significant protective effect on brain damage and cognitive dysfunction in transient focal cerebral ischemia.

• The Journal of Korean Medicine
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• v.26 no.2 s.62
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• pp.52-62
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• 2005

Objectives: This study was conducted to determine the effects of Geupunggibodan on brain damage in transient focal cerebral ischemia in rats. Methods: Rats were used for testing in the following three models: Morris water maze, eight-ann radial maze, and histochemistry. Results: In the Morris water maze model, the Geupunggibodan group showed significant decrease in the 3rd, 4th and 6th training sessions compared with the ischemia, group. A retention test in the Morris water maze model was performed on the 7th day without the escape platform. The Geupunggibodan group showed significant increase compared to the ischemia group. In the eight-ann radial maze model, the Geupunggibodan group showed significant decrease in the error rate compared to the ischemia group. In the density of hippocampal CA1 cell of the cresyl violet-stained section, the Geupunggibodan group showed significant increase compared to the ischemia group. Conclusions: These results suggest that Geupunggibodan may have a significant protective effect on brain damage and cognitive dysfunction in transient focal cerebral ischemia.

• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.3
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• pp.71-86
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• 2013

This research explores the question how interactions between customer and firm affect firm growth. To test suggested hypotheses, this study collects data on social commerce industry in Korea during the period from the beginning of social commerce industry in Korea, May 2010, to March 2012, and investigates the effect of social media on the growth of social commerce firms. We suggest two hypotheses in this study. First, as web traffic inflow through social media into a focal social commerce increases, the growth rate of the focal social commerce increases. Second, the more diverse social media channel through which web traffic inflows into a focal social commerce, the weaker the positive effect of web traffic inflow on the growth rate of the focal social commerce. Analysis of data shows that inflow through social media is positively related to the growth of social commerce. In addition, our analysis shows that inflow channel diversity weakens the positive relationship between web traffic inflow through social media and growth rate of social commerce firms. These results suggest that firms need to concentrate on few social media in order to attract customers. The study contributes to understanding how interaction between firms and customers influences the growth of the firm.

• Journal of the Korean Solar Energy Society
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• v.24 no.4
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• pp.11-18
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• 2004

A solar concentrator, named KIERDISH II, was built at KIER in order to investigate the feasibility of high temperature solar energy application system. The constructed concentrator is a dish type solar concentrator with a focal length of 4.68m and a diameter of 7.9m. To successfully operate KIERDISH II, optimal design of the absorber is very important and flux density distribution has to be known. The focal flux density distribution on the receiver was measured. We have observed the shape and size of flux images and evaluated percent power within radius. Flux density distribution is usually measured by a CCD(charge coupled device) camera and a radiometer. In this paper we present a flux mapping method to estimate the characteristic features of the flux density distribution in the focal region of solar concentrator. The minimum radius of receiver is found to be 0.15m and approximately 90% of the incident radiation is intercepted by receiver aperture.

• Korean journal of communication and information
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• v.48
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• pp.306-325
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• 2009

This Study aims to thesis the purpose and educational methodology of media education for senior citizens. As background research, current situation and agendas regarding the media education for senior citizens were investigated. In further, quantative focal interview method was deployed to analyze recognition of teaches and education participants in media education for senior citizens. Focal interviews basis on the purpose, problems of education environment, preferred education method and suggestions of media education. The focal interview lead to in-depth opinion relying on experience of teachers and education participants. This study is expected to present the basis data for future theoretical systemization of neglected classes and for seeking educational utilization methods.

• The Journal of Korean Medicine
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• v.25 no.1
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• pp.117-128
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• 2004

Objectives : This research was performed to investigate effect of Samul-tang-gamibang against focal cerebral ischemic damage after middle cerebral artery occlusion(MCAO). Methods : This research was used rats which were against focal cerebral ischemic damage by MCAO. It was used Zea Longa's theory and Belayev's methods to give rise to focal cerebral ischemic damage by MCAO. After 7days later, we drew out the brain and then had frozen and dyeing it and we had taken a picture to measure of the damaged area in each brain section. We determined the Neurological Index and tested the Foot-fault test and Roatated test to appraise the fall of motion ability result from cerebral ischemic damage. Results : The results of the experiment are as follows. 1. Samul-tang-gamibang reduced infarct size of sample group compared to control group at 7 day after MCAO. 2. Samul-tang-gamibang reduced infarct volume of sample group compared to control group at 7 day after MCAO. 3. Samul-tang-gamibang reduced foot-fault index of sample group compared to control group at 5,7 day after MCAO. Conclusions : Samul-tang-gamibang has protective effects against ischemic brain damage and had significant reduced infarct size and infarct volume of Rt-MCAO.

• The Journal of Korean Physical Therapy
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• v.21 no.4
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• pp.111-115
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• 2009

Purpose: The aim of this study was to present fundamental information regarding clinical prognosis and clinical criteria for therapeutic intervention in stroke patients with focal pons infarction. Methods: Four stroke patients (male: 2, female: 2) who were diagnosed with pons infarction were recruited. All subjects had motor functions evaluated using methods such as the Motricity Index (MI), the Modified Brunnstrom Classification (MBC), Functional Ambulatory Category (FAC), and the Bathel Index (BI). Evaluations were done at least 4 times over a period that was approximately 8~11 months from stroke onset. We compared the final evaluation with the first evaluation. Results: All patients with focal pons infarction showed improvement with time in motor function. The physical strength of all patients was improved to normal or good grades from zero or trace grades in the Motricity Index test. Also, other motor functions such as ambulatory capacity and activities of daily living (ADL) improved with time. Conclusion: Aspects of functional recovery and clinical prognosis are clearly predictable for specific patients with focal pons infarction. In addition, adequate therapeutic interventions can be provided clinical criterion to patients, according to aspect of functional recovery. Accordingly, patients with pons infarction change for the better over time.

• Journal of Technology Innovation
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• v.6 no.2
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• pp.122-158
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• 1998

This study empirically examined different patterns of collaborative R&D project with their key success factors(KSFs), using data from 82 projects in the Korean electronic parts industry. The patterns of R&D collaboration were categorized into 4 types by two criteria development motive(technology Push/market pull) and Project initiator (focal firm/partner). The bivariate relationships revealed that project characteristics (technological complexity, market uncertainty), management characteristics (participation in project formulation), problem solving characteristics(problem solving performance of the focal firm, users active role in problem solving, active role of university or research institute in problem solving) and success rates appear to be different among four types of collaboration. Each type of collaborative R&D projects also had different KSFs. The KSFs of type 1 (technology Push and focal firm initiation), for instance, include the strategic importance of the project, focal firms share of cost, active role of university or research institute in problem solving, while those of type 4(market pull and customer initiation) cover reliability of partner relationship, a time at partners involvement, information sharing. The findings suggest that the different contingencies brought different patterns and KSFs of collaborative R&D project, since different information, resources, and partners roles were needed to successfully implement the projects according to development motive and project initiator Finally, managerial, policy, and theoretical implications for the collaborative R&D activities in the Korean electronics parts industry were discussed, based on empirical results of this study.