• The Korean Journal of Physiology and Pharmacology
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• 제8권1호
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• pp.33-41
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• 2004

We developed a cardiac cell model to explain the phenomenon of mechano-electric feedback (MEF), based on the experimental data with rat atrial myocytes. It incorporated the activity of ion channels, pumps, exchangers, and changes of intracellular ion concentration. Changes in membrane excitability and $Ca^{2+}$ transients could then be calculated. In the model, the major ion channels responsible for the stretch-induced changes in electrical activity were the stretch-activated channels (SACs). The relationship between the extent of stretch and activation of SACs was formulated based on the experimental findings. Then, the effects of mechanical stretch on the electrical activity were reproduced. The shape of the action potential (AP) was significantly changed by stretch in the model simulation. The duration was decreased at initial fast phase of repolarization (AP duration at 20% repolarization level from 3.7 to 2.5 ms) and increased at late slow phase of repolarization (AP duration at 90% repolarization level from 62 to 178 ms). The resting potential was depolarized from -75 to -61 mV. This mathematical model of SACs may quantitatively predict changes in cardiomyocytes by mechanical stretch.

• 대한임베디드공학회논문지
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• 제13권4호
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• pp.215-223
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• 2018

Recently, as interest of wearable devices has increased, commercially available smart wristbands and applications have been used as a tool for personal healthy management. However most previous studies have focused on evaluating the accuracy and reliability of the technical problems of wearable devices, especially step counts, walking distance, and energy consumption measured from the smart wristbands. In this study, we propose a physical activity evaluation model using classification rules, induced from the associative classification mining approach. These rules associated with five physical activities were generated by considering activities and walking times in target heart rate zones such as 'Out-of Zone', 'Fat Burn Zone', 'Cardio Zone', and 'Peak Zone'. In the experiment, we evaluated the prediction power of classification rules and verified its effectiveness by comparing classification accuracies between the proposed model and support vector machine.

• 한국통신학회논문지
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• 제35권8C호
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• pp.661-666
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• 2010

본 논문에서는 비음수 행렬 인수분해 기법을 기반으로 한 새로운 음성 검출 (Voice Activity Detection, VAD) 알고리즘을 제안한다. 먼저, 기존의 통계모델기반의 음성검출기를 분석하고, 이를 기반으로 비음수 행렬 인수분해를 통해 도출한 입력 기초 벡터와 잡음 기초 벡터 차이로 음성의 유무를 판단한다. 이때 최적의 문턱값을 찾기 위해 통계모델 기반의 음성검출기에 의해 추정된 잡음 구간에서 NMF 결과의 분포에 따라 최적화된 문턱값을 비음수 행렬기반의 음성 검출 알고리즘에 적용하는 방법을 제안한다. 실험 결과 기존의 통계적 모델 기반의 음성검출기에 비해 6.75%의 성능향상을 가져왔다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.734-743
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• 2007

고속철도 정차역은 시설현황, 정차역의 위치, 주변 토지이용 등 역세권 주변의 개발 정도에 따라 정차역에서 유발 및 유입되는 통행량에 큰 차이를 보이게 되며, 역과 역세권이 잘 발달된 정차역은 유동인구가 상당히 많음에 따라 특별구역(시설물)으로 정의되어질 수 있다. 이러한 특별구역은 많은 통행량을 발생시키는 토지이용 구역으로서 대학교, 공항, 대형쇼핑몰 등이 해당되어 왔으며 고속철도의 이용자가 증가함에 따라 정차역이 지역 내 통행수요에 미치는 영향을 고려하였을 때 특별구역으로 정의 될 필요가 있다. 지역내 교통처리 계획 및 연계교통계획 수립을 위해 특별구역에 대한 통행수요추정은 예전부터 상당한 관심이 요구되어 왔다. 그러나 전통적인 4단계 모형의 통행발생 및 분포 모형으로는 이러한 특별구역의 통행수요를 예측하는데 한계가 있으므로 개인별 통행행태를 고려할 수 있는 새로운 분석방법인 활동기반모형(Activity-Based Travel Demand Model)의 적용이 필요하다. 이에 본 연구에서는 고속철도 정차 역의 교통수요추정을 위해 활동기반 모형의 적용방안에 대하여 소개하며 향후, 적용가능성에 대하여 제시하도록 한다.

• 산업경영시스템학회지
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• 제34권4호
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• pp.89-97
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• 2011

Traditional quality control for manufacturing or service sector is not suitable for the quality control of a project as the project is one-time task constrained by time, cost, and quality. To meet the internal and external customers' requirements, quality costs approach to the project will be effective. Hence, we propose PONC (price of nonconformance) estimation procedure and a mathematical model, which are focused on activity-based prevention in the execution step and warranty step of EPLC (extended project life cycle). This procedure and model will help project manager develop preventive action plan for project quality costs minimization from nonconformance risk activities and PONC estimates information.

• 대한간호학회지
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• 제41권4호
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• pp.500-509
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• 2011

Purpose: Time-driven activity-based costing was applied to analyze the nursing activity cost and efficiency of a medical unit. Methods: Data were collected at a medical unit of a general hospital. Nursing activities were measured using a nursing activities inventory and classified as 6 domains using Easley-Storfjell Instrument. Descriptive statistics were used to identify general characteristics of the unit, nursing activities and activity time, and stochastic frontier model was adopted to estimate true activity time. Results: The average efficiency of the medical unit using theoretical resource capacity was 77%, however the efficiency using practical resource capacity was 96%. According to these results, the portion of non-added value time was estimated 23% and 4% each. The sums of total nursing activity costs were estimated 109,860,977 won in traditional activity-based costing and 84,427,126 won in time-driven activity-based costing. The difference in the two cost calculating methods was 25,433,851 won. Conclusion: These results indicate that the time-driven activity-based costing provides useful and more realistic information about the efficiency of unit operation compared to traditional activity-based costing. So time-driven activity-based costing is recommended as a performance evaluation framework for nursing departments based on cost management.

• Bulletin of the Korean Chemical Society
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• 제30권11호
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• pp.2749-2753
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• 2009

Structural characteristics that influence on the insecticidal activity ($pI_{50}$) of 2-(n-octyl)isothiourea analogues (1-45) against the diamondback moth (Plutella xylostella, L.) based on three dimensional quantitative structure activity relationships (3D-QSARs) were discussed quantitatively using a comparative molecular field analysis (CoMFA) and a comparative molecular similarity indeces analysis (CoMSIA) methods. The statistical values of the CoMFA 2 model were better than those of the CoMSIA 1 model. The CoMFA 2 model was the optimized model with the correlativity (the training set: Ave. = 0.104 & PRESS = 0.613) and the predictability (the test set: Ave. = 0.086 & PRESS = 0.096). Insecticidal activities with the optimized CoMFA 2 model were dependent upon steric factors (79.4%) of $R_1-R_3$ substituents. From the analytical results of CoMFA contour maps, it is predicted that the R1 substituent of 1-45 which has a steric favor in a broad space, $R_2\;and\;R_3$ groups with a steric favor in a narrow space and a H-bond donor favor would have better the insecticidal activity.

• 한국정보과학회논문지:소프트웨어및응용
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• 제32권6호
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• pp.486-501
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• 2005

XPDL(XML Process Definition Language)은 프로세스 정의 교환을 위하여 WfMC에서 제안한 XML 기반 언어이다. 본 논문에서는 워크플로우 프로세스의 정의와 교환을 위하여 XPDL 문서의 구조(Schema)를 UML 다이어그램으로 모델링하여 기업들 간의 상호연동과 협업을 위한 업무흐름 파악을 용이하게 하는 모델을 제안한다. 이를 위해 XPDL 문서를 UML의 클래스 다이어그램과 액티비티 다이어그램으로 변환하는 사상 규칙을 정의하여, XPDL 프로세스 메타모델(Meta-Model)를 구성하는 각 엘리먼트는 클래스 다이어그램으로 모델링하고, 프로세스 액티비티(Process Activity)는 액티비티 다이어그램으로 모델링하는 기법을 제안한다. 또한 제안된 기법을 "신용 카드 상태 체크 시스템"의 워크플로우에 대한 XPDL 문서을 적용하여 제안된 기법의 유효성을 검증한다.

• 유통과학연구
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• 제14권8호
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• pp.45-50
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• 2016

Purpose - This study aimed to develop a new practical and universally applicable service quality model by improving the service quality measurement model proposed by many previous studies. Research design, data, and methodology - An in-depth analysis on what influences such service quality model had on the improvement effect of service quality, and Service Evaluation Model("SEM"), which was revised from the existing service quality measurement model, was developed. The model is divided into the two integrative categories: First, activity, that is the group of service-related activities. Next is item, the group of service-related objects. The level of service is evaluated for each category via survey questionnaire on service level evaluation. Based on the model, SEM has visibility by structuring the whole service industry. Results - For the application of the new service quality model, this study attempted to examine the appropriateness of the newly proposed service quality model by applying it to retail service field. Conclusions - As a result, the proposed service model would be a useful and applicable service quality measurement model required by many organizations. Service company can set up self check service levels. Through these results, they can look for the ways to provide better services to customers. Service users can ensure the objectivity of business plan based upon SEM.

• 문화기술의 융합
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• 제9권1호
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• pp.355-360
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• 2023

최근 디지털의 발달로 아동들은 미디어 매체에 많이 접하고 있다. 독서 활동이 줄어 책에서의 정보를 습득하거나 습득한 정보를 정리하고 기억하는 것에 어려움을 겪는다. 증강현실이 접목된 교육이 학습에 대한 아동의 참여도와 몰입도를 높이므로, 우리는 아동의 독서 흥미도와 창의성을 높이기 위해 증강현실 기술이 도입된 독후활동 애플리케이션을 제안하였다. 또한, 5가지의 누리과정을 기반으로 애플리케이션에 들어갈 놀이 중심의 독후활동을 설계하였다. 애플리케이션 제안에서 그치지 않고 실제 수업에 사용할 수 있도록 놀이 중심의 수업 모형을 설계하였다. 수업 모형 설계에 따른 개념적인 사고의 틀을 분석하기 위해 실제 어린이집을 방문하고 전문가가 참관한 수업을 진행하였다. 참관한 전문가들에게 독후활동 수업 모델 및 운영의 적합성 검토를 위해 미리 제작한 설문지를 작성하게 하여 타당성을 검토하였다. 우리의 수업 모형 설계는 한정된 도서의 콘텐츠를 대상으로 하였으며, 윤리상의 문제로 아동 대상으로 대규모 실험을 진행하지 못하여 연구의 결과가 전체를 대표할 수 없다. 하지만 누리과정을 기반으로 한 새로운 독후활동 수업 운영의 가능성을 검토하고 제시하였다는 데에 의의가 있다.