• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.4
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• pp.462-469
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• 2011

In this paper, we propose a novel hybrid codebook design method which combines DFT matrix based codebook for Rayleigh fading and LOS codebook for direct path. Link-level performances employing hybrid codebook outperform the ones employing the conventional codebooks when K-factor of Rician distribution is 0.28 to 0.99. Moreover hybrid codebook shows good performances over not only Rayleigh channel but also high K's Rician channels.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.10B
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• pp.1240-1245
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• 2011

In this paper, channel modeling and analysis of wireless visible light communication(VLC) were studied in indoor circumstance. Photons emitted from LED straightly moved and navigated within indoor, after that a part of photons reached on PD via LOS(Line Of Sight) or NLOS(None Line Of Sight). These received signals had characteristics of delay profile and attenuation, which was multiple-path fading. In this paper, computer simulation of VLC channel was executed under the condition that two LEDs were used for transmitter and three PDs were located at different positions of the 20*8*2.3m sized indoor. BER performance simulation was excuted based on the characteristics of each VLC channel.

• Journal of Korean Academy of Nursing Administration
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• v.17 no.3
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• pp.327-335
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• 2011

Purpose: The objective of this study was to analyze the effects of medical staffing level as bed-to-medical staff ratio on patient outcomes as length of stay (LOS) among hospitals in Korea. Methods: Two hundred and fifty one hospitals participated in the study between January and March 2008. Data for the study was requested by an electronic data interchange from the Health Insurance Review Agency in 2008. In data analysis, SPSS WIN 15.0 program was utilized for descriptive statistics, t-test, ANOVA, Pearson correlation coefficients, and multiple regression. Results: The mean score for length of stay was 13.6 days. The mean of operating bed-to-nurse ratio was 7.93:1. The predicting factors for LOS were bed-to-nurse's aide ratio, bed-to doctor's ratio, severely ill patient rate, and hospital type. These factors explained 28.9% of the variance in patient outcomes. Conclusion: This study results indicate that the relationship between medical staffing level and patient outcomes is important in the improvement of the quality of patient care. Thus, improvements in the quality of the nurse practice environment could improve patient outcomes for hospitalized patients.

• Industrial Engineering and Management Systems
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• v.13 no.2
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• pp.185-192
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• 2014

This study stems from the work of Lehman et al. (Ergonomics, 2001) which concluded that standing yields better work performance, and from the growing health trend of recommending the reduction of the amount of time spent in sitting (Owen et al., Exercise and Sport Science Reviews, 2010). Lajoie et al. (Experimental Brain Research, 1993) provided an initial significant contribution to a theory that standing requires a person to control balance, equating to demand higher productive output from the cognitive system than when a person is sitting. An assumption was formulated that standing position during class is feasible and can be adopted on the belief that it might contribute positive results to students' performance. The purpose of this study is to identify whether a body position during exams tested along with exposure durations has a significant effect on college students' performance. Mathematical analysis and reading comprehension exam was used to measure the cognitive performance of the students. Two factors, position and duration, were tested for significance with two levels each subjected to six replicates. Twenty-four students from the College of Engineering and Agro-Industrial Technology, University of the Philippines Los Ba$\tilde{n}$os were randomly selected. The experiment showed that the body position during exams is a significant factor for the Math exam, but insignificant for the Reading Comprehension exam.

• Parasites, Hosts and Diseases
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• v.54 no.5
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• pp.605-616
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• 2016

In the present study, quids from La Cueva de los Muertos Chiquitos (CMC) were subjected to ELISA tests for 2 protozoan parasites, Toxoplasma gondii (n=45) and Trypanosoma cruzi (n=43). The people who occupied CMC, the Loma San Gabriel, lived throughout much of present-day Durango and Zacatecas in Mexico. The known pathoecology of these people puts them into at-risk categories for the transmission of T. gondii and T. cruzi. Human antibodies created in response to these 2 parasites can be detected in modern saliva using ELISA kits intended for use with human serum. For these reasons, quids were reconstituted and subjected to ELISA testing. All test wells yielded negative results. These results could be a factor of improper methods because there is no precedence for this work in the existing literature. The results could equally be a simple matter of parasite absence among those people who occupied CMC. A final consideration is the taphonomy of human antibodies and whether or not ELISA is a sufficient method for recovering antibodies from archaeological contexts. An additional ELISA test targeting secretory IgA (sIgA) was conducted to further examine the failure to detect parasite-induced antibodies from quids. Herein, the methods used for quid preparation and ELISA procedures are described so that they can be further developed by future researchers. The results are discussed in light of the potential future of quid analysis.

• Journal of Preventive Medicine and Public Health
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• v.45 no.4
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• pp.259-266
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• 2012

Objectives: This study aims to determine the risk factors predicting rehospitalization by comparing three models and selecting the most successful model. Methods: In order to predict the risk of rehospitalization within 28 days after discharge, 11 951 inpatients were recruited into this study between January and December 2009. Predictive models were constructed with three methods, logistic regression analysis, a decision tree, and a neural network, and the models were compared and evaluated in light of their misclassification rate, root asymptotic standard error, lift chart, and receiver operating characteristic curve. Results: The decision tree was selected as the final model. The risk of rehospitalization was higher when the length of stay (LOS) was less than 2 days, route of admission was through the out-patient department (OPD), medical department was in internal medicine, 10th revision of the International Classification of Diseases code was neoplasm, LOS was relatively shorter, and the frequency of OPD visit was greater. Conclusions: When a patient is to be discharged within 2 days, the appropriateness of discharge should be considered, with special concern of undiscovered complications and co-morbidities. In particular, if the patient is admitted through the OPD, any suspected disease should be appropriately examined and prompt outcomes of tests should be secured. Moreover, for patients of internal medicine practitioners, co-morbidity and complications caused by chronic illness should be given greater attention.

• Journal of Preventive Medicine and Public Health
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• v.46 no.4
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• pp.183-191
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• 2013

Objectives: In Korea, the proportion of deaths due to alcohol is estimated at 8.9%, far exceeding the global estimate of 3.8%. Therefore, this study was performed to examine the factors associated with low-risk, moderate-risk, and high-risk drinking patterns in Korean adults and to identify target populations for prevention and control of alcohol-related diseases and deaths. Methods: We analyzed data from 230 715 Korean adults aged 19 years and older who participated in the 2009 Korean Community Health Survey. Multinomial logistic regression analysis was used to examine associations between socio-demographic and health-related factors and patterns of alcohol use. Results: A substantially larger proportion of men than women engaged in high risk (21.2% vs. 3.4%) and moderate-risk alcohol use (15.5% vs. 8.2%). In both sexes, moderate- and high-risk uses were associated with younger age, higher income, being currently employed, smoking, being overweight/obese, and good self-rated health. Conclusions: Given the large proportion of the population that is engaging in moderate- and high-risk drinking and given the social norms that support this behavior, public health policies and campaigns to reduce alcohol consumption targeting the entire population are indicated.

• Structural Engineering and Mechanics
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• v.69 no.1
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• pp.95-104
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• 2019

The Standard ASCE 61-14 proposes the Substitute Structure Method (SSM) as a Nonlinear Static Procedure (NSP) to estimate nonlinear displacement demands at the center of mass of piers or wharves under seismic actions. To account for bidirectional earthquake excitation according to the Standard, results from independent pushover analyses in each orthogonal direction should be combined using either a 100/30 directional approach or a procedure referred to as the Dynamic Magnification Factor, DMF. The main purpose of this paper is to present an evaluation of these NSPs in relation to four wharf model structures on soil conditions ranging from soft to medium dense clay. Results from nonlinear static analyses were compared against benchmark values of relevant Engineering Design Parameters, EDPs. The latter are defined as the geometric mean demands that are obtained from nonlinear dynamic analyses using a set of 30 two-component ground motion records. It was found that SSM provides close estimates of the benchmark displacement demands at the center of mass of the wharf structures. Furthermore, for the most critical pile connection at a landside corner of the wharf the 100/30 and DMF approaches produced displacement, curvature, and force demands that were reasonably comparable to corresponding benchmark values.

• Proceedings of the Korean Society of Computer Information Conference
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• 2024.01a
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• pp.41-43
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• 2024

본 연구에서는 Vision Transformer 기반의 Anomaly Detection and Localization (VT-ADL) 모델에 초점을 맞추고, 손실 함수의 변경이 MVTec 데이터셋에 대한 이상 검출 및 지역화 성능에 미치는 영향을 비교 분석한다. 기존의 손실 함수를 KL Divergence와 Log-Likelihood Loss의 조합인 VAE Loss로 대체하여, 성능 변화를 심층적으로 조사했다. 실험을 통해 VAE Loss로의 전환은 VT-ADL 모델의 이상 검출 능력을 현저히 향상시키며, 특히 PRO-score에서 기존 대비 약 5%의 개선을 보였다는 점을 확인하였다. 이러한 결과는 손실 함수의 최적화가 VT-ADL 모델의 전반적인 성능에 중요한 영향을 미칠 수 있음을 시사한다. 또한, 이 연구는 Vision Transformer 기반 모델의 이상 검출과 지역화 작업에 있어서 손실 함수 선택의 중요성을 강조하며, 향후 관련 연구에 유용한 기준을 제공할 수 있을 것으로 기대된다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.127-134
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• 2012

Four river project in the South Korea contributes to solve flood damages and water shortages. Also, it has purpose for creating water ecosystem and improving the level of people' cultural leisure and quality of life through inducing water quality improvement and river restoration. It is necessary to monitor a variety of observing data in river areas among dozens to hundreds of kilometer for safe river administration. The 20th construction area of the four river project is located on Hapcheon areas, where wireless mesh network was installed to manage the basin. In the process of network construction, the characteristic of surrounding areas is considered about embodying secure service by investing the least expense. Besides, transmission environment analysis is performed such as LOS tests and reception level analysis, and transmission speed measurement to create safe service. Reception level in all places is confirmed among -55 dBm ~ -70 dBm, and data transmission speed proves more than 20 Mbps.