• Journal of Internet Computing and Services
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• v.24 no.2
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• pp.19-26
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• 2023

Humans have adapted and evolved to natural light. However, as humans stay in indoor longer in modern times, the problem of biorhythm disturbance has been induced. To solve this problem, research is being conducted on lighting that reproduces the correlated color temperature(CCT) of natural light that varies from sunrise to sunset. In order to reproduce the CCT of natural light, multiple LED light sources with different CCTs are used to produce lighting, and then a control index DB is constructed by measuring and collecting the light characteristics of the combination of input currents for each light source in hundreds to thousands of steps, and then using it to control the lighting through the light characteristic matching method. The problem with this control method is that the more detailed the steps of the combination of input currents, the more time and economic costs are incurred. In this paper, an LED lighting control method that applies interpolation and combination calculation based on the minimum spectral power distribution information for each light source is proposed to reproduce the CCT of natural light. First, five minimum SPD information for each channel was measured and collected for the LED lighting, which consisted of light source channels with different CCTs and implemented input current control function of a 256-steps for each channel. Interpolation calculation was performed to generate SPD of 256 steps for each channel for the minimum SPD information, and SPD for all control combinations of LED lighting was generated through combination calculation of SPD for each channel. Illuminance and CCT were calculated through the generated SPD, a control index DB was constructed, and the CCT of natural light was reproduced through a matching technique. In the performance evaluation, the CCT for natural light was provided within the range of an average error rate of 0.18% while meeting the recommended indoor illumination standard.

• Journal of the Korean Society of Radiology
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• v.3 no.3
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• pp.5-11
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• 2009

When using Image Guided Radiation Therapy, the patient is placed using skin marker first and after confirming anatomical location using OBI, the couch is moved to correct the set up. Evaluation for the error made at that moment was done. Through comparing $0^{\circ}$ and $270^{\circ}$ direction DRR image and OBI image with 2D-2D matching when therapy planning, comparison between patient's therapy plan setup and actual treatment setup was made to observe the error. Treatment confirmation on important organs such as head, neck and spinal cord was done every time through OBI setup and other organs such as chest, abdomen and pelvis was done 2 ~ 3 times a week. But corrections were all recorded on OIS so that evaluation on accuracy could be made through using skin index which was divided into head, neck, chest and abdomen-pelvis on 160 patients. Average setup error for head and neck patient on each AP, SI, RL direction was $0.2{\pm}0.2cm$, $-0.1{\pm}0.1cm$, $-0.2{\pm}0.0cm$, chest patient was $-0.5{\pm}0.1cm$, $0.3{\pm}0.3cm$, $0.4{\pm}0.2cm$, and abdomen was $0.4{\pm}0.4cm$, $-0.5{\pm}0.1cm$, $-0.4{\pm}0.1cm$. In case of pelvis, it was $0.5{\pm}0.3cm$, $0.8{\pm}0.4cm$, $-0.3{\pm}0.2cm$. In rigid body parts such as head and neck showed lesser setup error compared to chest and abdomen. Error was greater on chest in horizontal axis and in AP direction, abdomen-pelvis showed greater error. Error was greater on chest in horizontal axis because of the curve in patient's body when the setup is made. Error was greater on abdomen in AP direction because of the change in front and back location due to breathing of patient. There was no systematic error on patient setup system. Since OBI confirms the anatomical location, when focus is located on the skin, it is more precise to use skin marker to setup. When compared with 3D-3D conformation, although 2D-2D conformation can't find out the rolling error, it has lesser radiation exposure and shorter setup confirmation time. Therefore, on actual clinic, 2D-2D conformation is more appropriate.

• Management & Information Systems Review
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• v.36 no.4
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• pp.21-32
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• 2017

Motivated by the recent cases of negligent social responsibility as manifested by foreign luxury fashion brands in Korea, this study investigates whether agency costs depend on the sustainability of different types of corporate governance. Agency costs refer either to vertical costs arising from the relationship between stockholders and managers, or to horizontal costs associated with the potential conflicts between majority and minority stockholders. The firms with luxury fashion brand could spend large sums of money on maintenance of magnificent brand image, thereby increasing the agency cost. On the contrary, the firms may hold down wasteful spending to report a gaudily financial achievement. This results in mitigation of the agency cost. Agency costs are measured by the value of the principal component. First, three ratios are constructed: asset turnover, operating expense to sales, and earnings before interest, tax, and depreciation. Then, the scores of each of these ratios for individual firms in the sample are differenced from the ratios for the benchmark firm of S-OIL. S-OIL was designated as the best superior governance model firm for 2013 by CGS. We perform regression analysis of each agency cost index, luxury fashion brand dummy and a set of control variables. The regression results indicate that the agency costs of the firms with luxury fashion brand exceed those of control group in the fashion industry in the part of operating expenses, but the agency cost falls short of those of control group in the part of EBITD, thus the aggregate agency costs are not differential of those of the control group. In sensitivity test, the results are same that the agency cost of the firms are higher than those of the matching control group with PSM(propensity matching method). These results are corroborated by an additional analysis comparing the group of the companies with the best brands with the control group. The results raise doubts about the effectiveness of management of the firms with luxury fashion brand. This study has a limitation that the research has performed only for 2013 and this paper suggests that there is room for improvement in the current research methodology.

• Journal of agricultural medicine and community health
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• v.43 no.1
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• pp.9-17
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• 2018

Objectives: This study was to assess the status and awareness of excessive heat exposure among agricultural workers. Methods: We selected a total of 90 farmers from a villages of Gyeongju-si, during August, 2015. We carried out the temperature measurement for nine times and derived Health Index (HI) and Wet Bulb Globe Temperature (WBGT) index. We compared the HI, WBGT and excessive heat warnings. Status of high temperature exposure, lifestyle, medical history, and awareness about excessive health related exposure illness assessed using survey questionnaires. Results: The matching rates between the WBGT and the HI during excessive heat warning were high, but when it was a non-excessive heat warning, there were days of excessive HI or WBGT. Out of 90 farmers surveyed, 78 cases (86.7%) were in their 60s and older age group. Slightly more than two third (71.1%) farmers were farming in the dawn-morning (71.1%), and the daily working hours were less than 4 hours (54.4 %), but only 23.3% among farmers took regular breaks. Of total, 14.4% farmers experienced excessive heat exposure related illness in order of tiredness, lethargy, dizziness, headaches, and sweating. Overall, the awareness of the danger for excessive heat and the heat wave warnings were high at 70.0% and 74.4%, respectively. Conclusions: Politically, the excessive heat warnings should not be taken into account the simple temperature measurement but, have to consider WBGT and HI standards at the same time. Farmers need to be promoted and educated to prevent the excessive heat related illness by periodically increasing their rest time during farming.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.669-678
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• 2018

This study developed information technology infrastructures for building a driving environment analysis platform using various big data, such as vehicle sensing data, public data, etc. First, a small platform server with a parallel structure for big data distribution processing was developed with H/W technology. Next, programs for big data collection/storage, processing/analysis, and information visualization were developed with S/W technology. The collection S/W was developed as a collection interface using Kafka, Flume, and Sqoop. The storage S/W was developed to be divided into a Hadoop distributed file system and Cassandra DB according to the utilization of data. Processing S/W was developed for spatial unit matching and time interval interpolation/aggregation of the collected data by applying the grid index method. An analysis S/W was developed as an analytical tool based on the Zeppelin notebook for the application and evaluation of a development algorithm. Finally, Information Visualization S/W was developed as a Web GIS engine program for providing various driving environment information and visualization. As a result of the performance evaluation, the number of executors, the optimal memory capacity, and number of cores for the development server were derived, and the computation performance was superior to that of the other cloud computing.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.11
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• pp.2535-2540
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• 2010

In traditional Publish/Subscribe system, the first procedure to deliver event from publisher to subscriber is that publisher publishes publisher's event to broker. Next step is that broker checks simple binary notion of matching : an event either matches a subscription or it does not. Lastly, broker delivers the event matched with subscriptions to the corresponding subscribers. In this system, information delivery has been accomplished in one way only. However, current some applications require two way delivery between subscriber and publisher. Therefore, we initiate an extended Publish/Subscribe system that supports two way delivery. Extended Publish/Subscribe system requires additional functions of delivering subscription to publisher and especially deciding top-n subscriptions using priority because broker might has a number of subscriptions. In this paper, we propose two priority retrieval techniques based on SIF using IS-List with deciding priority among subscriptions and defining SIF(Specific Interval First). The performance measurements show that RSO(resulting set sorting) technique results in better performance in index creation time and ITS&IS(insertion time sorting and inverse search using stack) technique results in better performance in search time.

• Journal of agricultural medicine and community health
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• v.25 no.2
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• pp.293-302
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• 2000

The relationship between sodium intake and stomach cancer risk has been studied much in Japan but a great portions still remain controversial. There has been few studies on relationship between sodium intake and stomach cancer in Korea. The goal of this nested case-control study is to investigate the association between sodium intake and stomach cancer risk in a rural county of Korea We estimated sodium intake indirectly by the threshold of salt-water taste of patients. This study was based on both of the data from 'Kangwha Cohort Study' which had been conducted from March 1985 and 'Kangwha Community Cancer Registry' which had been launched on July in 1982 by the College of Medicine, Department of Preventive Medicine. Yonsei University. A total of 145 patients who developed stomach cancer in Kangwha County were initially recruited as the case group. We tried to get two community-controls per stomach cancer case by matching age and gender. Finally we got information from 90 cases and 146 controls about the threshold of the salt taste and preference of salty food and so on. Some 79% of the information about ease group came from proxy respondents and 56% among controls. Risk ratios of developing stomach cancer adjusted for smoking, body mass index and self-stated health level were estimated. No statistically significant association between the threshold of salt taste and stomach cancer risk found in this study. We recommend some further studies utilizing urinary salt excretion, diet record method for better estimating of salt intake with a paticular emphasis on interaction effect between salty and spicy food in hospital-based case-control study designs.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.1
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• pp.97-107
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• 2002

In this paper, we propose the realization of on-line handwritten Chinese character recognition for mobile personal digital assistants (PDA). We focus on the development of an algorithm having a high recognition performance under the restriction that PDA requires small memory storage and less computational complexity in comparison with PC. Therefore, we use index matching method having computational advantage for fast recognition and we suggest a unit reconstruction method to minimize the memory size to store the character models and to accomodate the various changes in stroke order and stroke number of each person in handwriting Chinese characters. We set up standard model consisting of 1800 characters using a set of pre-defined units. Input data are measured by similarity among candidate characters selected on the basis of stroke numbers and region features after preprocessing and feature extracting. We consider 1800 Chinese characters adopted in the middle and high school in Korea. We take character sets of five person, written in printed style, irrespective of stroke ordering and stroke numbers. As experimental results, we obtained an average recognition time of 0.16 second per character and the successful recognition rate of 94.3% with MIPS R4000 CPU in PDA.

• Journal of Technology Innovation
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• v.21 no.1
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• pp.141-163
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• 2013

As the importance of biotechnology has been increased as a growth engine for country, most countries get focused on securing technological competitiveness in the field of biotechnology. Under the fierce global competition, it is very important to identify technological competitiveness of Korea and our neighboring countries in order to carry out effective research and development. Expert opinion survey such as Delphi is mainly conducted to analyze the technological competitiveness, but the method based on experts' intuition may produce different results depending on survey respondents due to the strong subjective inclination. In this study, the patent registered in US was utilized to analyze the technological competitiveness based on objective data. Targeting countries were Korea, China and Japan which were leading nations in the Northeast Asia. As analytical indexes, NP(Number of Patents), CPP(Cites per Patent), PII(Patent Impact Index), TS(Technology Strength), TI(Technology Independence), PFS(Patent Family Size) were used for analysis. Moreover, the industrial linkage with biotechnology was analyzed by matching IPC code of patents with 44 industries. Based on this analysis, technological convergence and utilization were quantified. The findings can be utilized as basic data when policy is established to improve technological competitiveness in the field of biotechnology.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.2
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• pp.841-848
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• 2013

Background: The incidence of various types of cancers including the non-Hodgkin's lymphoma (NHL) has increased during the recent years. Diet and lifestyle factors have been reported to play an important role in the etiology of NHL. However, no such data are available from the Middle Eastern countries, including Oman. Materials and Methods: Forty-three histologically confirmed cases of non-Hodgkin's lymphoma (NHL) diagnosed at the Sultan Qaboos University Hospital (SQUH) and the Royal Hospital (RH), Muscat, Oman and forty-three age and gender matched controls were the subjects of this study. Frequency matching was used to select the control population. Information on social and demographic data as well as the dietary intake was collected by personal interviews, using a 117-items semi-quantitative food frequency questionnaire. Results: A non-significant increased risk of NHL was observed with higher body mass index (BMI) (OR=1.20, 95%CI: 0.45, 2.93), whereas a significantly decreased risk of NHL was associated with a higher educational level (OR=0.12, 95%CI: 0.03, 0.53). A significantly increased risk was observed for higher intake of energy (OR=2.67, 95%CI: 0.94, 7.57), protein (OR=1.49, 95%CI: 0.54, 4.10) and carbohydrates (OR=5.32, 95%CI: 1.78, 15.86). Higher consumption of daily servings from cereals (OR=3.25, 95%CI: 0.87, 12.09) and meat groups (OR=1.55, 95%CI: 0.58, 4.15) were also found to be associated with risk of NHL, whereas a significantly reduced risk was associated with higher consumption of vegetables (OR=0.24, 95%CI: 0.07, 0.82). The consumption of fruits, milk and dairy products however showed no significant association with the risk of developing NHL. Conclusion: The results suggest that obesity, high caloric intake, higher consumption of carbohydrate and protein are associated with increased risk of NHL, whereas a significantly reduced risk was observed with higher intake of vegetables.