• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.1
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• pp.14-21
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• 2008

In this paper, we propose an adaptive contrast enhancement method using dynamic range segmentation. Histogram Equalization (HE) method is widely used for contrast enhancement. However, histogram equalization method is not suitable for commercial display because it may cause undesirable artifacts due to the significant change in brightness. The proposed algorithm segments the dynamic range of the histogram and redistributes the pixel intensities by the segment area ratio. The proposed method may cause over compressed effect when intensity distribution of an original image is concentrated in specific narrow region. In order to overcome this problem, we introduce an adaptive scale factor. The experimental results show that the proposed algorithm suppresses the significant change in brightness and provides wide histogram distribution compared with histogram equalization.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.14 no.2
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• pp.98-103
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• 2003

Background and Objectives : Although many studies have examined the effect of drinking on voice change, its cause and degree remain unclear. Since voice change occurs more frequently the day following drinking, rather than immediately afterwards, we examined whether the voice change was correlated with reflux laryngitis due to gastroesophageal motor disturbances. Subjects and Methods : For this study, 10 patients were selected who had neither voice change nor symptoms of reflux laryngitis at baseline (male : female=5 : 5, mean age=28 years old) They were subjected to psychoacoustic, acoustic, and aerodynamic tests and video stroboscopy at 4:00 P.M. the day before drinking (test 1), at 8:00 A.M. (test 2) and 4:00 P.M. (test 3) on the following day. On the day of drinking, the subjects had to drink more than their usual amount of Soju(Korean liquor) and were not allowed to talk much. The stroboscopy findings were quantified using the PC Belafsky score. Results : The laryngeal response to gastric reflux after drinking was compared between tests 1 and 2. In both tests, laryngeal edema and injection were observed on video stroboscopy. The psychoacoustic test detected more severe hoarseness in test 2 than in test 1. In addition, the acoustic test detected a mild increase in both jitter and shimmer. However, the differences between tests 2 and 3, which were performed when there was reduced or no gastric reflux, were not significant. Conclusions : Drinking may cause gastric reflux, which produces reversible voice change by irritating the vocal cords and larynx. Therefore, reflux laryngitis should be suspected in a patient whose voice changes markedly after drinking.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.31 no.1
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• pp.26-35
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• 2022

Patients who miss teeth partially or fully show many changes which make them lose function and esthetics.From the esthetic point of view, loosing teeth makes lower face unharmonized. There are various changes of lower and whole face according as how much change oral cavity is. Restoring the multiple teeth missing properly can make patient's face harmonized. Especially full mouth implant restorations can cause drastic occlusal change affecting masticatory muscles. Because all the muscles are connected closely, the masticatory muscles which is part of lower facial muscles can cause whole muscle change. In full mouth implant restoration case, I will show the whole face muscle change harmonized by meticulous occlusal treatment process. Full mouth restorations installed in right way show whole face muscle changes extending to head and neck muscles.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.281-290
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• 2017

As various stakeholders are involved in construction projects, disputes between the parties are more likely to occur, which is a very important issue for the participants in the projects. Claims in construction projects, however, are very complex and thus difficult to manage. In particular, as the cause of a claim in the preceding stage that has not been resolved in a timely manner has an effect on the cause of a claim in the following stage, it is difficult to find a point of compromise regarding a claim caused by the relationship between the causes that occur in the preceding and following stages. In this regard, this study sought to examine the rules for the generation of change order claims, which occur most frequently among the construction claims, and thus to select the key management targets through the analysis of the relationship between the causes of claims arising in the preceding and following stages for the efficient management of claims. It is expected that the use of rules for the generation of change order claims as well as of representative and similar cases will help the construction practitioners in judging claims, considering the relationships among the causes of the claims. Meanwhile, in this study, association analysis was conducted regarding the causes of the occurrence of change order claims in a design-build delivery method, and therefore, it is necessary to verify the effectiveness of the method when applied to other delivery methods.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1090-1094
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• 2007

The aim of this study is to estimate the cause of Cooling Tower vibration and eliminate the faults of fan with high vibration in spite of overhaul. The cause of high vibration was that the natural frequency of fan blade coincide with second blade pass frequency. To achieve reduction of Cooling Tower vibration, change motor speed from 1784rpm to 1714rpm, and then the vibration has reduced conspicuously.

• Korean Institute of Interior Design Journal
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• v.24 no.3
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• pp.104-112
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• 2015

This study purposes drawing changing tendency of apartment kitchen areas and character of that by figuring out type, form and per period cause of change of brand apartment kitchen areas. I adopted subject of study as the six leading construction companies considering the apartment rankings of brand and subcontract from 2001 to 2015 when brand apartment was activated(Samsung C&T corporation Raemian, Daelim Industrial Co., Ltd E-pyeonhansesang, Daewoo E&C Prugio, GS E&C XI, Posco E&C The sharp, Hyundai E&C Hillstate) and analyzed kitchen plane of $84m^2{\sim}102m^2$ housing units which were in great demand from apartment housing market. Also, I drew changing trends of kitchen areas by conducting a model house field survey. Through this study result, I will expect the utility of baseline data which is necessary for space development by figuring out kitchen culture, flows and cause of change.

• Journal of Korean Society for Quality Management
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• v.50 no.3
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• pp.533-543
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• 2022

Purpose: The purpose of this study is to identify and resolve the causes of defects in the unmanned aerial vehicle launch system(propulsion wire fracture, rear rail deformation) and to prevent recurrence. Methods: The causes of the two defects were derived through fault tree analysis for each of the two defects and fault reproduction tests. In the case of propulsion wire, the installation of a high speed camera to check the behavior of wire was the driving force behind the defect resolution. Results: The results of this study are as follows; It was determined that the thickness of the washer was less than the maximum tolerance of the pulley was the cause of the propulsion wire fracture defect. Failure to comply with the launch procedure and insufficient safety margin were judged as the cause of the rear rail deformation defect. Accordingly, the configuration was changed to remove each defect. Conclusion: The case of this study was conducted to eliminate defects in the launch system for UAV. The causes of defects were estimated through fault tree analysis. After the configuration change, Structural analysis and launch tests were performed to demonstrate the safety and effectiveness of the modified configuration. As a result, the effect of the modified configuration was verified.

• Korean Institute of Interior Design Journal
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• no.17
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• pp.3-11
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• 1998

This study puroses to grasp the change of dwelling space by the change of family organization according to the change of population in the rural area of suburbs of city that suppose to receive the influence of the city. The method of this study is to collect data about form village houses in monographs and reference books and study change factor of houses. To the selected village we will interview local inhabitants and officials and observe and survey the farm village houses by visiting houses. Through the research results we will know the change of population organization that cause the change of room utilization. We know that village pepole have living articles in dwelling space. We expect that the farm village houses will become city houses only in the dwelling space. So the suburban farm houses must be planned as in relation with the city.

• Korean Journal of Acupuncture
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• v.17 no.1
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• pp.123-140
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• 2000

The purpose of this study is to understand the special character and the tendency of the movement change that 12 meridians possess. We studied about the incidental and fundamental rule of the six atmospheric influence that was presented by Pyobonjoong(the incidental, fundamental, intermediate) theory, and the Hwang won-uh's the Six Channel activity of the Qi theory that presented movement form of the meridian through the six atmospheric influence. Then we found the following substances. The Pyobonjoong(the incidental, fundamental, intermediate) theory is applicable to understand the special character and the tendency of the movement change that Meridians possess. But, because the Pyobonjoong(the incidental, fundamental, intermediate) theory can't classify the characteristic difference of the hand and foot meridians, then the principle that can devide the meridians of the hand and foot, must be supplied. The Jungwha(right changing)-Daewha(opposite changing) theory is able to concretely classify the special character of the hand and foot six meridians. And Hwang's Shawha(superintending change)-Jongwha(following change) theory that is base on Jungwha(right changing)-Daewha(opposite changing) theory, is able to classify the special character of the hand and foot six meridians, too. If the concept of the Meridians is understood by the Shawha(superintending change)-Jongwha(following change) theory, the special character of the hand and foot six meridians could be concretely classified and then the meridian of the Bowels and the six atmospheric influence corresponded to the meridians could be expansively explained as the point that take charge and control these special Qi in the human body The Bon-Qi(fundamental Qi) act on the special character of Shawha(superintending change) six meridians and the tendency of the movement change is cause by the insufficiency and excessiveness of the Bon-Qi(fundamental Qi). The Qi of the Shawha(superintending change) meridians act on the special character of Jongwha(following change) six meridians and the tendency of the movement change is cause by the exuberance of Yang and the deficiency of Yang.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1283-1287
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• 2009

The Korean government implemented 259 road projects from 2004 to 2007, valued at $18.4 billion. Change orders of these road projects occurred 8,973 times and, subsequently, caused significant increases in the cost of the projects, approximately up to $4.2 billion (22.8% of the initial budget). These significant problems of huge change orders require a more workable control system for budget management whereas the effectiveness of the government's control is still not satisfied. However, previous approaches and studies mostly limited their analyses to simply classifying the causes of the change orders. This paper investigates the real frequency and cost impacts incurred by each cause of a change order, primarily based on 218 road projects in Korea. The paper then identifies the attributes of change orders through a survey of 204 project participants in that those sources were inevitable or avoided if properly managed. The causes of the change orders are further analyzed with analysis of variance (ANOVA) in connection with contract volume, bid award rate, the contractor's capacity to perform, and the design company's capacity. This study found that if the contract volume is smaller, then the possibility of change orders is higher. Interestingly, if the bid award rate is less than 67.5%, it signifies the highest rate of change orders. In addition, the contractors whose construction ability is assessed as the top-ranked group showed the lowest change order rates. With these results, this paper provides the preventive guidelines for reducing the likelihood of change orders.