• Journal of Korean Society of Water and Wastewater
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• v.37 no.6
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• pp.363-373
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• 2023

Numerous studies have established a correlation between sociodemographic characteristics and water usage, identifying population as a primary independent variable in mid- to long-term demand forecasting. Recent dramatic sociodemographic changes, including urban concentration-rural depopulation, low birth rates-aging population, and the rise in single-person households, are expected to impact water demand and supply patterns. This underscores the necessity for operational and managerial changes in existing water supply systems. While sociodemographic characteristics are regularly surveyed, the conducted surveys use aggregate units that do not align with the actual system. Consequently, many water demand forecasts have been conducted at the administrative district level without adequately considering the water supply system. This study presents an upward water demand forecasting model that accurately reflects real water facilities and consumers. The model comprises three key steps. Firstly, Statistics Korea's SGIS (Statistical Geological Information System) data was reorganized at the DMA level. Secondly, DMAs were classified using the SOM (Self-Organizing Map) algorithm to consider differences in water facilities and consumer characteristics. Lastly, water demand forecasting employed the PCR (Principal Component Regression) method to address multicollinearity and overfitting issues. The performance evaluation of this model was conducted for DMAs classified as rural areas due to the insufficient number of DMAs. The estimation results indicate that the correlation coefficients exceeded 0.9, and the MAPE remained within approximately 10% for the test dataset. This method is expected to be useful for reorganization plans, such as the expansion and contraction of existing facilities.

• Tunnel and Underground Space
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• v.34 no.2
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• pp.154-168
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• 2024

The Tunnel Boring Machine (TBM) disc cutter is subjected to wear and damage during the rock excavation process, and the worn disc cutter should be replaced on time. The manual inspection by workers is generally required to determine the disc cutter replacement. In this case, the workers are exposed to dangerous environments, and the measurements are sometimes inaccurate. In this study, we developed a technology that measures the disc cutter wear in real time. From a series of laboratory tests, a magnetic sensor was selected as the wear sensor, and the real-time disc cutter measurement system was developed integrating wireless communication modules, power supply and data processing board. In addition, the measurement system was verified in actual TBM excavation circumstances. As a result, it was confirmed that the accuracy and stability of the system.

• Studies on Life and Culture
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• v.53
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• pp.135-161
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• 2019

The purpose of this study was to explore the relationship between the level of empathy of care service(Elderly, Disabled, Mother & Newborn, Patient, Cancer Patient) workers and health and workplace spirituality. For this purpose, 1,051 care service workers in Busan were surveyed and among them, 861 participant answered and finally without 49 insufficient answers, 814 answers got chosen and analyzed. The results are as follows; First, the higher the level of physical health and work place spirituality, the higher the level of empathy of care service workers. Second, work place spirituality has more influence on the empathy of care service workers than physical health. Finally, there is no statistically significant influence on empathy by characteristics of Sociodemographic, the work environment and work environment risk of the care service workers. This study has concluded that in order to raise the level of empathy of care service workers, it is necessary to improve the physical health and workplace spirituality of care service workers.

• Therapeutic Science for Rehabilitation
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• v.7 no.4
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• pp.19-30
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• 2018

Objective: The purpose of this study was to suggest predictors of participation restriction in community-dwelling Spinal Cord Injury (SCI) based on environmental, functional, injury-related, psychosocial, and sociodemographic factors. Methods: The participants were 82 community-dwelling SCI adults over the age of 18. They were all included in the American Spinal Injury Association's (ASIA) Levels A, B, and C. This study surveyed participants' participation using the CHART-K-SF, environmental factors using the CHIEF-25 Korean version, and functional factors using the SCIM III. Further, pain and distress were surveyed using Zung's Self-rating Pain and the PAD, self-esteem was assessed using the RSES, and self-efficacy using the GSS. Finally, information concerning injury levels, post-injury period, causes of injury-related factors, and sociodemographic factors such as gender, age, marriage, education level, and residence information were collected. The collected data were analyzed using SPSS Version 21.0 Results: Participants' risk factors were environmental and functional. The Nagelkerke's $R^2$ was.737. The OddsRatio(OR) of environmental factors(referent,0-1) was 40.346. Moreover, the OR of the $1^{st}$ quartile functional factor(referent,4thquartile) was 236. 621, and that of the$2^{nd}$ quartile was 21.174. In addition, the occupational predictors included the "policies" subscales in the CHART-K-SF, "physical/structural" in the CHIEF-25, and "mobility" in the SCIM III. Further, the predictors of "physical independence" were "services/assistance" in CHIEF-25, and "respiration and sphincter management' on the SCIM III. Additionally, "mobility" was predicted by "physical/structural" on the CHIEF-25 and "mobility" on the SCIM III. Conclusions: This study multidimensionally confirmed predictors of participation restriction. Through these facts, we investigated occupational therapists' roles in community setting. Therefore, this study's results will provide useful information for occupational therapy services, for which the goal is SCI participation improvement within the community.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.11a
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• pp.415-418
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• 2007

가까운 미래에 인간생활에 활용될 지능형 로봇은 인간과 공존하면서도 효과적으로 인간을 도와줄 수 있는 인간친화형 로봇이라 할 수 있다. 이러한 것을 실현하기 위해서 로봇은 미지의 환경 내에서 자신의 위치 및 방향을 인식해야 할 필요가 있다. 더욱이, 이것은 일상생활에서 자연스럽게 이뤄지는 것이 당연하다. 로봇을 제어하는 가장 중요한 문제중의 하나로서 이동로봇의 주행에서의 위치불확실성을 해결함으로서 로봇의 위치를 추정하는 것이 바람직하다 할 수 있다. 본 논문에서는 실내외 공간에서 인간을 포한함 이동물체의 영상정보를 이용하여 이동로봇의 자기위치를 인식하기 위한 방법을 제시하고 있다. 제시한 방법은 로봇자체의 DR센서 정보와 카메라에서 얻은 영상정보로부터 로봇의 위치추정방법을 결합 한 것이다. 그리고 이동물체의 이전 위치정보와 관측 카메라의 모델을 사용하여 이동물체에 대한 영상프레임 좌표와 추정된 로봇위치 간의 관계를 표현할 수 있는 식을 제시하고 있다. 또한 이동하는 인간과 로봇의 위치와 방향을 추정하기 위한 제어방법을 제시하고 이동로봇의 위치를 추정하기위해서 칼만필터 방법을 적용하였다. 그리고 시뮬레이션 및 실험을 통하여 제시한 방법을 검증하였다.

• The Journal of the Acoustical Society of Korea
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• v.16 no.4
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• pp.5-10
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• 1997

In this paper, a new time delay estimation algorithm, WTD-LMSTDE was proposed. This method has great improvement in convergence rate relative to the time domain approach by decreasing the eigen value spread of input signal autocorrelation matrix. The performance of the algorithm was evaluated for the cases of time invariant time delay and time varying time delay. In the case of time invariant time delay, the estimation accuracy of WTD-LMSTDE was better than that of LMSTDE from 3.3% to 12.5% with respect to SNR. In the case of time varying time delay, the mean error power of WTD-LMSTDE in linear increased delay environment was decreased about 2.4dB compared to that of LMSTDE under noise-free condition. As a result, we showed that the performance of WTD-LMSTDE is better than of LMSTDE.

• Communications for Statistical Applications and Methods
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• v.19 no.3
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• pp.459-469
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• 2012

This article proposes a couple of parallel implementations of the self-organizing network for normal mixtures. In principle, self-organizing networks should be able to be implemented in a parallel computing environment without issue. However, the network for normal mixtures has inherent problem in being operated parallel in pure sense due to estimating conditional expectations of the mixing proportion in each iteration. This article shows the result of the parallel implementations of the network using Java. According to the results, both of the implementations achieved a faster execution without any performance degradation.

• Journal of Adhesion and Interface
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• v.11 no.4
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• pp.168-173
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• 2010

Flame retardant halogen containing compounds have been replaced as environmentally safe material which does not contain hazardous materials generating toxic gas. Self-extinguishing epoxy resin compositions have been studied in order to produce eco-friendly epoxy molding compound, which is used as insulating materials in semiconductor. We developed self-extinguishing epoxy resin compositions which do not contain halogen compounds with new epoxy resin (E3). The new epoxy molding compound (EMC-1) showed high flame resistance (UL-V0) and high thermal resistance ($451.9^{\circ}C$ at 5 wt% loss) enough to use as eco-friendly material.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.575-582
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• 2012

The focus on the tourism development after executing the local self-governing system has been changed into a software from a hardware. Especially, the local self-governing bodies in recent years have found their local attractions, and then made them into the tourist contents (branded as a kind of commercial article) which can represent their local culture and environment. They are positively making the most of the contents for their public relations. But, as the tourist contents are used as a limited form, they need to be developed as a city brand which is comprehensive and unifying. Accordingly, in this paper, the C-city was selected as an example. and a city brand of C-city was made on the basis of the tourist contents.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.01a
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• pp.149-152
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• 2013

이 연구는 스마트교육환경에서의 교육용 앱을 평가하기 위한 신뢰롭고 타당한 도구를 개발하는데 있다. 기존 선행연구에 기초해서 교육용 앱의 평가를 위한 평가모형을 도출했으며, 이 모형은 4개의 평가영역(교수 학습측면, 화면디자인측면, 기술측면, 경제 윤리측면)과 13개 평가요소들로 구성되었다. 이 잠재모형의 통계적 타당성 검증을 위한 자료수집을 하고자, 경기도 소재 중학교 1곳과 고등학교 2곳의 학생 156명을 대상으로 교육용 앱을 평가하는데 있어서 각 평가문항이 갖는 중요도를 평가하였다. 수집된 자료를 탐색적 요인분석한 결과, 교육용 앱을 평가하는 영역으로 교수 학습(흥미성 자기주도성 실용성, 인지발달성), 화면디자인(디자인의 적합성, 어휘의 정확성), 기술(호환성, 안정성), 경제 윤리(경제성, 윤리성) 등 4개 영역이 제안되었다. 또한 문항내적일관성을 확인하고자 신뢰도 분석한 결과, 각 평가영역 별 Cronbach ${\alpha}$는 .88, .85, .82, .80으로 모두 적합한 수준을 보였다. 따라서, 이 연구를 통해 도출된 교육용 앱 평가도구는 통계적으로나 타당성과 신뢰성 측면에서 의미 있는 것으로 판단할 수 있다.