• Title/Summary/Keyword: Tool-based Approach

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A Study on the Crack Initiation Life for Crankshaft of Mid-size Engine (중형엔진 크랭크축의 균열발생수명에 대한 고찰)

  • Juh-H. Ham;Myung-H. Hyun;Su-H. Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.32 no.3
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    • pp.126-134
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    • 1995
  • The crack initiation life evaluation which is the most commonly used approach in fatigue strength studies for the designers, is performed for the crankshaft of mid-size engine. In order to evaluate the fatigue strength, structural analysis model and applied loads on crankshaft are prepared based on the cyclic system. Using the response data of the finite element analysis, crack initiation life is predicted and plotted on crankshaft geometric model. In this analysis, general purpose programs such as PATRAN, NASTRAN and EMRC/NISA are actively utilized. Life distribution contour plots, which is not yet established as an active tool in actual design system of ship structure & components, are suggested and examples for active predicting procedure such as stress contour plotting in structure strength analysis, are illustrated. Additionally, several correlated equations for prediction of the crack initiation life are introduced and discussed to improve the fatigue strength prediction of crankshaft.

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A Study on the patient satisfaction for nursing care in a general hospital. (일 종합병원 간호사의 간호행위에 대한 환자 만족도 조사연구)

  • Kang, Ik-Wha
    • Journal of Korean Academy of Nursing Administration
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    • v.3 no.2
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    • pp.137-150
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    • 1997
  • This study was done to evaluate patient satisfaction with nursing care. The study subjucts were 164 patients admitted in a general hospital in Incheon province. The instrument used in this study was developed by Risser (1975) and Lim Hae Kyoung (1980) based on classification of nursing care area and modified by Chow Kwang Nam (1995). The relaiability alpha of this tool was 0.93695. The survey method was applied to collect data and the period of data collection was total 30 days from April Ist to April 30th in 1997. The data was analyzed by statistical method of %, mean, t-test and ANOVA through SAS program. 1. The highest scores of satisfaction were shown in the area of reliance, area of treatment, area of environment and area of education in order. 2. The crossed analysis of patient general characteristics and satisfaction of nursing care showed a signficance in the department of patient's admission and the highest satisfaction score was found in the general surgery ward (p<0.05). 3. General characteristics of patients which influence on the satisfaction showed a significant response according to the department of patient's admission in the treatment area, education area and environment area of nursing.(p < 0.05). Recommendation The followings are deriven from the above study results. 1. Area of nursing education which showed the lowest satisfaction should be empathized by making improvement of nursing care approach because the area in the basis to achieve nursing goal. 2. The development of systematic and objective instrument is necessary for evaluation of nursing quality and the evaluation should be performed in the area of patient satisfaction, hospital facility and hospital environment as well.

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Numerical simulation of fish nets in currents using a Morison force model

  • Cifuentes, Cristian;Kim, M.H.
    • Ocean Systems Engineering
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    • v.7 no.2
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    • pp.143-155
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    • 2017
  • For complex flexible structures such as nets, the determination of drag forces and its deformation is a challenging task. The accurate prediction of loads on cages is one of the key steps in designing fish farm facilities. The basic physics with a simple cage, can be addressed by the use of experimental studies. However, to design more complex cage system for various environmental conditions, a reliable numerical simulation tool is essential. In this work, the current load on a cage is calculated using a Morison-force model applied at instantaneous positions of equivalent-net modeling. Variations of solidity ratio ($S_n$) of the net and current speed are considered. An equivalent array of cylinders is built to represent the physical netting. Based on the systematic comparisons between the published experimental data for Raschel nets and the current numerical simulations, carried out using the commercial software OrcaFlex, a new formulation for $C_d$ values, used in the equivalent-net model, is presented. The similar approach can also be applied to other netting materials following the same procedure. In case of high solidity ratio and current speed, the hybrid model defines $C_d$ as a function of Re (Reynolds number) and $S_n$ to better represent the corresponding weak diffraction effects. Otherwise, the conventional $C_d$ values depending only on Re can be used with including shielding effects for downstream elements. This new methodology significantly improves the agreement between numerical and experimental data.

Ground surface changes detection using interferometric synthetic aperture radar

  • Foong, Loke Kok;Jamali, Ali;Lyu, Zongjie
    • Smart Structures and Systems
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    • v.26 no.3
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    • pp.277-290
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    • 2020
  • Disasters, including earthquakes and landslides, have enormous economic and social losses besides their impact on environmental disruption. Iran, and particularly its Western part, is known as an earthquake susceptible area due to numerous strong ground motions. Studying ecological changes due to climate change can improve the public and expert sector's awareness and response to future disastrous events. Synthetic Aperture Radar (SAR) data and Interferometric Synthetic Aperture Radar (InSAR) technologies are appropriate tools for modeling and surface deformation modeling. This paper proposes an efficient approach to detect ground deformation changes using Sentinel-1A. The focal point of this research is to map the ground surface deformation modeling is presented using InSAR technology over Sarpol-e Zahab on 25th November 2018 as a study case. For surface deformation modeling and detection of the ground movement due to earthquake SARPROZ in MATLAB programming language is used and discussed. Results show that there is a general ground movement due to the Sarpol-e Zahab earthquake between -7 millimeter to +18 millimeter in the study area. This research verified previous researches on the advanced image analysis techniques employed for mapping ground movement, where InSAR provides a reliable tool for assisting engineers and the decision-maker in choosing proper policies in a time of disasters. Based on the result, 574 out of 682 damaged buildings and infrastructures due to the 2017 Sarpol-e Zahab earthquake have moved from -2 to +17 mm due to the 2018 earthquake with a magnitude of 6.3 Richter. Results show that mountainous areas have suffered land subsidence, where urban areas had land uplift.

Hands-on Tools to Prevent Human Errors in Highway Construction (고속도로 건설현장의 인적오류 예방을 위한 실무자용 도구 개발)

  • Kim, Jung-Yong;Yoon, Sang-Young;Cho, Young-Jin
    • Journal of the Ergonomics Society of Korea
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    • v.30 no.1
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    • pp.19-28
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    • 2011
  • Objective: The aim of this study is to reclassify human errors and to develop hands-on tools to apply the new classification for preventing human error accidents in highway construction site. Background: The main cause of accidents in highway construction was reported as the carelessness of workers. However, such diagnosis could not help us operationally prevent accidents in real workplace. Method: The accidents in highway construction were reanalyzed and the causes of human error were reclassified in order to educate and improve the awareness of human error in highway construction. Field survey and interview with safety managers and workers were conducted to find the causal relationship between the actual accidents and the human errors. Results: The most frequently observed human errors in highway construction were classified into six categories such as mis-perception, distraction, memory fail, slip, cognition error and mis-judgment. In order to provide hands-on tools to increase the awareness of human error in construction field, the human error checklist and card sorting diary were developed. Especially, the card sorting diary was designed to increase the ability in human error inspection of safety manager at construction site. Moreover, posters were developed based on actual accident cases. Conclusion: We suggested that the improved awareness and analytical report on checklist, card sorting diary and posters for construction field could collectively prevent the accident. Application: The classification of human error, hands-on tools and posters can be directly applicable on highway construction site. This analytical and collective approach preventing human error-related accident could be extended to other construction workplaces.

Comparative Analysis of Cultivation Region of Angelica gigas Using a GC-MS-Based Metabolomics Approach (GC-MS 기반 대사체학 기술을 응용한 참당귀의 산지비교분석)

  • Jiang, Guibao;Leem, Jae Yoon
    • Korean Journal of Medicinal Crop Science
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    • v.24 no.2
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    • pp.93-100
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    • 2016
  • Background: A set of logical criteria that can accurately identify and verify the cultivation region of raw materials is a critical tool for the scientific management of traditional herbal medicine. Methods and Results: Volatile compounds were obtained from 19 and 32 samples of Angelica gigas Nakai cultivated in Korea and China, respectively, by using steam distillation extraction. The metabolites were identified using GC/MS by querying against the NIST reference library. Data binning was performed to normalize the number of variables used in statistical analysis. Multivariate statistical analyses, such as Principal Component Analysis (PCA), Partial Least Squares-Discriminant Analysis (PLS-DA), and Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA) were performed using the SIMCA-P software. Significant variables with a Variable Importance in the Projection (VIP) score higher than 1.0 as obtained through OPLS-DA and those that resulted in p-values less than 0.05 through one-way ANOVA were selected to verify the marker compounds. Among the 19 variables extracted, styrene, ${\alpha}$-pinene, and ${\beta}$-terpinene were selected as markers to indicate the origin of A. gigas. Conclusions: The statistical model developed was suitable for determination of the geographical origin of A. gigas. The cultivation regions of six Korean and eight Chinese A. gigas. samples were predicted using the established OPLS-DA model and it was confirmed that 13 of the 14 samples were accurately classified.

CT Classification and Treatment of Intraarticular Calcaneal Fractures - Conservative vs. Surgical Treatment by Prospective Study - (관절내 종골 골절의 전산화 단층 촬영에 따른 분류 및 치료)

  • Kang, Jae-Do;Kim, Hyung-Chun;Kim, Jin-Hyung
    • Journal of Korean Foot and Ankle Society
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    • v.5 no.1
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    • pp.35-42
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    • 2001
  • Purpose: To analyze the results of conservative or surgical treatment after computed tomograhy(CT) classification in intraarticular calcaneal fractures. Materials and methods: From January 1996 to May 1999, we prospectively analyze 23 cases of intraarticular calcaneal fractures who were treated conservatively or operated by open reduction and internal fixation by extensive L-shaped lateral approach after CT classification. Results: A functional scoring system of 0-100 points which was based upon the responses to AOFAS Ankle-Hindfoot Scale for the operative group was at 82.8, compared with 73.2 for the non-operative group, and these were meaningful statistically(P<0.05). Of type I fracture, in the operative group there were 2 excellent results and in the non-operative group there were 2 excellent results, 1 good result. or type II fractures, in the operative group there were 2 excellent results, 3 good results, 1 fair result and in the non-operative group there were 1 good result, 1 fair result, 2 poor results. Of type III fractures, in the operative group there were 2 fair results, 2 poor results and in the non-operative group there were 1 fair result, 3 poor results. Bohler angles of subtalar joint were changed from initial average $13.3^{\circ}$ to postoperative average $20.9^{\circ}$ for the operative group compared with from initial average $15.5^{\circ}$ to follow-up average $14.8^{\circ}$ of the non-operative group(P<0.01). Conclusions: Computed tomography in the evaluation of intraarticular calcaneal fractures is effective tool. We believed that open reduction and internal fixation in all Crosby & Fitzgibbons type II and according to degrees of comminution reducible type III for the intraarticular calcaneal fractures is more effective method than conservative treatment.

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Framework for Developing RFID Applications Based on Product Line Architecture (프로덕트라인 아키텍처 기반 RFID 애플리케이션 개발을 위한 프레임워크)

  • Moon, Mi-Kyeong;Kim, Han-Jun;Yeom, Keun-Hyuk
    • The KIPS Transactions:PartD
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    • v.14D no.7
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    • pp.773-782
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    • 2007
  • Software produce line engineering is a method that prepares for future reuse and supports seamless reuse in the application development process. Analyzing the commonality and variability between products in a product line is one of the essential concerns that must be considered when building a product line. In this paper, we suggest to combine a product line engineering approach with RFID applications technology. More concretely, common activities are identified among the RFID-enable applications and the variability in the common activities is analyzed in detail. Then, we suggest reusable product line architecture as a product line asset. In addition, as a tool for supporting this research, a framework which provides both reusable product line architecture for REID applications and the components that implement concrete realization of the architecture is developed. Sharing a common architecture and reusing assets to deploy recurrent services may be considered an advantage in terms of economic significance and overall quality.

Prediction of Transient Ischemia Using ECG Signals (심전도 신호를 이용한 일시적 허혈 예측)

  • Han-Go Choi;Roger G. Mark
    • Journal of the Institute of Convergence Signal Processing
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    • v.5 no.3
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    • pp.190-197
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    • 2004
  • This paper presents automated prediction of transient ischemic episodes using neural networks(NN) based pattern matching method. The learning algorithm used to train the multilayer networks is a modified backpropagation algorithm. The algorithm updates parameters of nonlinear function in a neuron as well as connecting weights between neurons to improve learning speed. The performance of the method was evaluated using ECG signals of the MIT/BIH long-term database. Experimental results for 15 records(237 ischemic episodes) show that the average sensitivity and specificity of ischemic episode prediction are 85.71% and 71.11%, respectively. It is also found that the proposed method predicts an average of 45.53[sec] ahead real ischemia. These results indicate that the NN approach as the pattern matching classifier can be a useful tool for the prediction of transient ischemic episodes.

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An Ontological Approach for Conceptual Modeling of Mission Space in Military Modeling & Simulation (국방 Modeling & Simulation에서 임무공간 개념모델링을 위한 온톨로지 적용방안)

  • Bae, Young Min;Kang, Haeran;Lee, Jonghyuk;Lee, Kyong-Ho;Lee, Young Hoon
    • Journal of Information Technology and Architecture
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    • v.9 no.3
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    • pp.243-251
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    • 2012
  • This paper presents the Conceptual Models of the Mission Space-Korea (CMMS-K), which is an ontology-based conceptual modeling framework of the mission space. Through modeling and simulating military trainings, we can reduce the cost of actual military trainings in terms of time, space, and supplies. CMMS-K is being developed to improve the interoperability and reusability of defense models and simulations. CMMS-K reflects the needs and characteristics of Korean military while referring to existing military conceptual modeling frameworks. The main components of CMMS-K contain domain ontologies, a mission space model description language, a mission space modeling tool, and a CMMS-K management system. CMMS-K domain ontologies consist of entity and task ontologies. In this paper, the CMMS-K domain ontologies are described in detail and the feasibility of the proposed method is discussed with a case study.