• Journal of Technologic Dentistry
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• v.34 no.3
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• pp.291-302
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• 2012

Purpose: It is to survey old men's utilization status of dental clinic and temporary-binding dentures and then to provide basic data to make a program for manufacturing old men's dentures and their teeth health education. Methods: Random selection was made on old men living in Daejeon and Chungnam, and a survey was conducted from April 15 to May 20, 2011. 500 questionnaires were distributed and 420 questionnaires were collected. Using spss 18.0 program, final analysis was made on 363 questionnaires except for 57 questionnaires which had missing value or showed some doubts about the unreliability. Results: 1. With respect to number of natural teeth as per the age, the upper/lower jaws had meaningful differences (P<.001), which means that the older the person is, the smaller number of natural teeth is. In the meantime, there was no meaningful difference according to sex. 2. With respect to kind of prosthetics installed in a mouth as per the age, there was meaningful difference in the upper jaws (P<.05) but there was no meaningful difference in the lower jaws. It was found out that the older the persons are, the more they use removable dentures while the younger the persons are, the more they use fixed partial dentures. 3. With respect to mouth health condition recognized by oneself, it showed bad (44.4%) and good (10.3%),which means recognition as bad is greater, and the age when prosthetics were first used is dispersed variously from below 40 to over 70. 4. Dental care institutions which they mainly used are hospital and clinics (91.5%), and 66.4% of them visited dental clinics lately. Preferential treatment if they go to dentists is as follows in the order of prosthetics (33.9%), gum treatment (24.2%) and pain treatment (14.9%). 5. 68.4% of them revisited dentists after installation of dentures and the reason for revisit is as follows in the order of poorly fitted dentures (35.1%), painful gum 25.9%, regular check-up 25.4% and difficult chewing 9.6%. Conclusion: As our country enters into an aging society, mouth health problem of old men has come to a serious issue, and therefore, a survey was conducted on some old men with respect to their utilization status of dental clinic and removable dentures in order to provide basic data for improvement of quality of their life, maintenance and enhancement of their mouth health. The study result shows that the older they are, the higher the loss rate of teeth as well as needs for prosthetics are, and thus it is thought the study will help to develop mouth health education program which may improve quality of old men's life by recovery of mouth functions declined due to loss of teeth and by regular check-up, education for mouth health control and following-up control of dentures.

• Analytical Science and Technology
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• v.25 no.2
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• pp.91-101
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• 2012

A list of volatile fatty acids (VFA) including propionic acid, butyric acid, isovaleric acid, valeric acid, etc. is well known for offensive odorants. The analysis of odorant VFA is a highly delicate task due to high reactivity and unstable recovery rate. At present, analytical methods of VFA are recommended to include alkali impregnation filter method and alkali absorption method by the malodor prevention law of the Korea Ministry of Environment (KMOE). In this review, a survey has been made to explore various approaches available for the analysis of VFA to include both official methods of the KMOE and others. In light of the unreliability of those established analytical methods, it is highly desirable to develop some substituting methods for VFA. Among such options, one may consider such option as sorbent tube (ST) sampling and cryogenic trapping-thermal desorption technique. Moreover, procedures used for standard preparation, sampling steps, and instrumental detection stage are also evaluated. Application of container sampling (like Tedlar bag) is however not recommendable due to significant (sorptive) loss in sampling and in storage stage. In the detection stage, the use of GC/MS is recommendable to replace GC/FID due to the presence of diverse interfering substances. Thus, it is essential to properly establish the basic quality assurance (QA) for VFA analysis in air.

• The Korean Journal of Applied Statistics
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• v.28 no.5
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• pp.907-920
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• 2015

Charts based on geometric distribution are effective to monitor the proportion of nonconforming items in high-quality processes where the in-control proportion nonconforming is low. The implementation of this chart is often based on the assumption that in-control proportion nonconforming is known or accurately estimated. However, accurate parameter estimation is very difficult and may require a larger sample size than that available in practice for high-quality process where the proportion of nonconforming items is very small. An inaccurate estimate of the parameter can result in estimated control limits that cause unreliability in the monitoring process. The maximum likelihood estimator (MLE) is often used to estimate in-control proportion nonconforming. In this paper, we recommend a Bayes estimator for the in-control proportion nonconforming to incorporate practitioner knowledge and avoid estimation issues when no nonconforming items are observed in the Phase I sample. The effects of parameter estimation on the geometric chart and the geometric CUSUM chart are considered when the MLE and the Bayes estimator are used. The results show that chart performance with estimated control limits based on the Bayes estimator is generally better than that based on the MLE.

• Fire Science and Engineering
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• v.23 no.3
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• pp.40-47
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• 2009

Nowadays the diversity and large-capacity of electric appliances are strong effect on electrical fires augment in an alarming way. But, as the inactive response characteristics of the existing RCD (Residual Current protective Device) used on low voltage power distribution system, so control of overload and electric short circuit faults, major causes of electrical fires, are not enough. Therefore, this paper is confirmed the unreliability of the existing RCD by electrical fault simulator and is proposed a Electrical Fire Disaster Prevention Device (EFDPD) by using a high precision current sensor (namely, reed switch) for the prevention of electrical disasters in low voltage power distribution system caused by overload or electric short circuit faults. The sensitive reed switch in the proposed EFDPD exactly detects the increased magnetic flux with the overload or the short current caused by a number of electrical faults, and the following, the EFDPD has double protection function which operates self circuit breaker or rapidly cuts off the existing RCD. The proposed EFDPD is confirmed the excellent characteristics in response velocity and accuracy in comparison with the conventional circuit breaker through various operation performance analysis. The proposed EFDPD can also prevent electrical disaster, like as electrical fires, which resulted from the malfunction and inactive response characteristics of the existing RCD.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.1
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• pp.143-155
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• 2018

The Natural Landscape Rating System was introduced in the amendment of the NATURAL ENVIRONMENT CONSERVATION ACT in 2006. For landscape preservation, the system aims to consider the effects of development projects or plans implemented in a natural landscape on skylines, scenic resources, and view corridors. Currently, a lack of consistency in standards for determining Landscape Control Points (LCP) to assess landscape impact lowers the accuracy and reliability of the assessment results. As the perception of and the impact on a landscape varies, depending on the location of the LCP, it is necessary to establish a reasonable set of criteria to select viewpoints and avoid unreliability in the assessment due to unclear criteria. The intent of this study is to propose an objective and reasonable set of criteria for LCP selection to effectively measure the impact on the landscape from development projects that anticipate a change in the landscape and, ultimately, to suggest basic analysis methods to assess the landscape impact of development projects and to monitor the landscape in the future. Among the development projects affecting natural landscapes, as reported in the statement of the environmental impact assessment, cases of construction of a single building or other small-scale development projects were studied. Four spot development projects were analyzed in depth for their landscape impacts, in order to make recommendations for the LCP selection procedure, which aims to widen the scope of selection according to the direction of viewpoints from the target site. The existing results of analysis based on LCP have limitations because they failed to cover the viewshed of the target buildings when there are topographical changes in the surroundings. As a solution to this problem, a new viewshed analysis method has been proposed, with a focus on the development site and target buildings, rather than viewpoints, as used in past analysis.

• Tuberculosis and Respiratory Diseases
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• v.41 no.6
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• pp.616-623
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• 1994

Objectives: Careful evaluation about mediastinal involvement is important in the management of patients with non-small cell lung cancer. Invasive staging procedure such as mediastinoscopy is advocated because of the unreliability of noninvasive staging methods such as CT, MRI. We compared differences between pre- and postoperative staging in non-small cell lung cancer without lymphadenopathy on CT scan and investigated the methods for more accurate preoperative staging. Methods & Results: 1) Records of a total of 41 patients with preoperative $T_{1-3}N_0M_0$ non-small cell lung cancer were reviewed and the histologic types of tumors were squamous cell carcinoma in 32 cases, adenocarcinoma in 6 cases and large cell carcinoma in 3 cases. Twenty-four cases were central lesions and seventeen cases were peripheral lesions. 2) Among the 32 cases with preoperative $T_2$, 2 cases were identified postoperatively as $T_3$ with invasion of chest wall and among 6 cases with preoperative $T_3$, 1 case was identified postoperatively as $T_4$ with invasion of aorta and pulmonary arteries. 3) After the operation of 35 cases with $T_{1-2}$, 5 cases were $N_1$ and 3 cases were $N_2$ postoperatively. After the operation of 6 cases with $T_3$, 2 cases were $N_1$ and 3 cases were $N_2$ postoperatively. Preoperative $T_3$ showed more intrathoracic lymph node metastases and higher $N_2/N_1$ involvement ratio than preoperative $T_{1-2}$. 4) Complete surgical resections were done in 34 out of 41 cases. Incomplete resection were done in all postoperative $N_2$ tumors. Conclusion: Invasive staging procedures such as mediastinoscopy should be considered in the case of preoperative $T_3$ non-small cell lung cancer even though mediastinal lymphadenopathy is not recognized on the CT scan of the chest.

• Journal of Intelligence and Information Systems
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• v.20 no.3
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• pp.1-18
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• 2014

Over the past years RFID/SN has been an elementary technology in a diversity of applications for the ubiquitous environments, especially for Internet of Things. However, one of obstacles for widespread deployment of RFID technology is the inherent unreliability of the RFID data streams by tag readers. In particular, the problem of false readings such as lost readings and mistaken readings needs to be treated by RFID middleware systems because false readings ultimately degrade the quality of application services due to the dirty data delivered by middleware systems. As a result, for the higher quality of services, an RFID middleware system is responsible for intelligently dealing with false readings for the delivery of clean data to the applications in accordance with the tag reading environment. One of popular techniques used to compensate false readings is a sliding window filter. In a sliding window scheme, it is evident that determining optimal window size intelligently is a nontrivial important task in RFID middleware systems in order to reduce false readings, especially in mobile environments. In this paper, for the purpose of reducing false readings by intelligent window adaption, we propose a new adaptive RFID data cleaning scheme based on window sliding for a single tag. Unlike previous works based on a binomial sampling model, we introduce the weight averaging. Our insight starts from the need to differentiate the past readings and the current readings, since the more recent readings may indicate the more accurate tag transitions. Owing to weight averaging, our scheme is expected to dynamically adapt the window size in an efficient manner even for non-homogeneous reading patterns in mobile environments. In addition, we analyze reading patterns in the window and effects of decreased window so that a more accurate and efficient decision on window adaption can be made. With our scheme, we can expect to obtain the ultimate goal that RFID middleware systems can provide applications with more clean data so that they can ensure high quality of intended services.

• Korean Journal of Culture and Social Issue
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• v.12 no.1
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• pp.129-160
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• 2006

The purposes of this study were to find 1) the realities of social anxiety and perception of various kinds of social problems that exists in Korean society as well as the perception on the events that causes the social anxiety, 2) to see the difference of perceived level of social anxiety through variables of social demography and difference of perception on Korean society. The sample was distributed according to population size distinguishing the nation to 6 regions. The data of 1,375 adult respondents were analysed. The results are as follows. First of all, respondents mentioned that the most immediate problem to be solved in Korean society was financial anxiety, and the most desirable state of society was when the society is financially stabled. Single question was measured about social anxiety of Korean society and scored 6.84 from full marks of 10, showing difference in variables for instance sex, age, and subjective S.E.S. where women, aged under 20, and perceived low class group showed the highest rate of social anxiety. However, there weren't any difference found in social anxiety of the variables like presence of religion, educational background, residence, and monthly average household income. Also, there were differences in level of social anxiety according to the difference of perception of Korean society. Higher the perceived unpredictability, uncontrollability, and unmovability to the upper class, unfairness, and uncertainty, unreliability of the Korean society, higher the social anxiety. And the lower the perceived chance of success of reformation, higher the social anxiety. It was also found that the perceived social anxiety is influenced by social accidents and phenomenon as unemployment, economic depression, and the gap between rich and poor as well as the increase of crime through effluence of personal information. Finally the limitations and implications of this study were discussed.