• Title, Summary, Keyword: human error

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Optimal Sensor Placement of Boundaries and Robustness Analysis for Chemical Release Detection and Response of Near Plant (주변 사업장의 화학물질 확산 감지와 대응을 위한 경계면의 센서배치 최적화 및 강건성 분석)

  • Cho, Jaehoon;Kim, Hyunseung;Kim, Tae-Ok;Shin, Dongil
    • Journal of the Korean Institute of Gas
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    • v.20 no.5
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    • pp.104-111
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    • 2016
  • Recently, the quantities of chemical material are increasing in chemical industries. At that time, release accident is increasing due to aging of equipment, mechanical failure, human error, etc. and industrial complexes found community properties in a specific area. For that matter, chemical release accident can lead to hight probability of large disaster. There is a need to analyze the boundaries optimal sensor placement calculated by selecting release scenarios through release condition and wether condition in a chemical process for release detection and response. This paper is to investigate chlorine release accident scenarios using COMSOL. Through accident scenarios, a numerical calculation is studied to determine optimized sensor placement with weight of detection probability, detection time and concentration. In addition, validity of sensor placement is improved by robustness analysis about unpredicted accident scenarios. Therefore, this verifies our studies can be effectively applicable on any process. As mention above, the result of this study can help to place mobile sensor, to track gas release based concentration data.

A Study on the Methods of Fault Analysis to Improve Safety in U-Healthcare System for Managing Emergency Rescue for Seniors (시니어들의 응급구난 관리를 위한 U-Healthcare시스템에서 안전성 개선을 위한 결함 분석 방법에 관한 연구)

  • Kim, Gyu-A;Park, Man-Gon
    • Journal of Korea Multimedia Society
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    • v.17 no.2
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    • pp.170-179
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    • 2014
  • Recently the U-Healthcare system has been rapidly advanced to manage emergence rescue for seniors. We can access emergency rescue systems with high quality services anytime, anywhere under ubiquitous healthcare systems. The more the various systems develop, the more software security systems become important. Therefore, the safety-critical system has been widely spread to the world by advancement of the information and communication technologies. There are a lot kind of fault analysis methods to evaluate software security systems. However due to characteristics of software that is not applied by human error, it can be prevented the enormous damages and losses from improving the safety of safety-critical system. So this paper proposes an integration method of FTA and Forward and Backward FMECA. This method has each strength of FTA and FMECA which is visual and numeric in normalization. First, by use of FTA, we can redraw FTA with Forward FMECA and Backward FMECA in consideration of occurrence, severity, detection, correctness, robustness, and security. Also according to value of NRVP at each event, we can modify FTA diagrams as shown critical paths given by severity and occurrence. Also, we propose the improved emergency rescue service platform of ubiquitous healthcare systems through identifying priorities of the criticality according to normalized risk priority values (NRPV).

Development of Nondestructive Evaluation System for Internal Quality of Watermelon using Acoustic Wave (음파를 이용한 비파괴 수박 내부품질 판정 시스템 개발)

  • Choi, Dong-Soo;Lee, Young-Hee;Choi, Seung-Ryul;Kim, Gi-Young;Park, Jong-Min
    • Korean Journal of Food Preservation
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    • v.16 no.1
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    • pp.1-7
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    • 2009
  • Watermelons (Citrulus vulgaris Schrad) are usually sorted manually by weight, appearance, and acoustic impulse, so grading of maturity and internal quality is subject to inaccuracies. It was necessary to develop a nondestructive evaluation technique of internal watermelon quality to reduce human error. Thus, acoustic characteristics related to internal quality factors were analyzed. Among these factors, three (ripeness, presence of an internal cavity, and blood-colored flesh) were selected for evaluation. The number of peaks and the sum of peak amplitudes for watermelons with blood-colored flesh were lower than for normal fruits. The portable evaluation system has an impact mechanism, a microphone sensor, a signal processing board, an LCD panel, and a battery. A performance test was conducted in the field. The internal quality evaluation model showed 87% prediction accuracy. Validation was conducted on 72 samples. The accuracy of quality evaluation was 83%. The quality of samples was evaluated by an inspector using conventional methods (hitting the watermelon and listening to the sounds), and then compared with prototype results. The quality evaluation accuracy of the prototype was better than that of the inspector. This nondestructive quality evaluation system could be useful in the field, warehouse, and supermarket

Comparison of Pepper Grafting Efficiency by Grafting Robot (접목로봇의 고추묘 접목 효율성 비교)

  • Kim, Hye Min;Hwang, Seung Jae
    • Protected Horticulture and Plant Factory
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    • v.24 no.2
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    • pp.57-62
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    • 2015
  • Manual grafting is a labor-intensive operation and highly susceptible to human error. Development of grafting robot has been considered as an effective alternative to manual grafting. The study was conducted to investigate the grafting efficiency between the domestically produced automated grafting robot and traditional manual grafting performed in a commercial plug seedling greenhouse. Plug seedlings of pepper (Capsicum annuum L.) 'Buchon' and 'Anseongmatchum' were sown as scions and rootstocks, respectively on March 29, 2013. The grafting was performed by a grafting robot, amateur grafters, and professional grafters on May 31, 2013. After grafting, the seedling efficiencies and seedling characteristics were compared in terms of plant height, the number of success as well as failure of seedling grafts produced in an hour. The results showed that plant heights were most uniform in the grafts performed by the professionals that had a 0.6 cm difference whereas an uneven difference of 2.1 cm difference was observed in plug seedling grafted by an amateur. However, plug seedlings grafted by the grafting robot were found to be uniform with 1 cm plant height difference. Moreover, the maximum number of grafting processed plug seedlings per hour (667 plants) was achieved by the grafting robot on compared with the seedlings grafted (466 plants) by the professionals. Furthermore, the least failure rate of 21.7% was noted upon the usage of grafting robot than the manual grafters. Thus, the results demonstrate that the technology of automated grafting robots is the most appealing and can be employed in commercial plug seedling greenhouses to overcome the drawbacks of manual grafting.

A 2MC-based Framework for Sensor Data Loss Decrease in Wireless Sensor Network Failures (무선센서네트워크 장애에서 센서 데이터 손실 감소를 위한 2MC기반 프레임워크)

  • Shin, DongHyun;Kim, Changhwa
    • Journal of the Korea Society for Simulation
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    • v.25 no.2
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    • pp.31-40
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    • 2016
  • Wireless sensor networks have been used in many applications such as marine environment, army installation, etc. The sensor data is very important, because all these applications depend on sensor data. The possibility of communication failures becomes high since the surrounding environment of a wireless sense network has an sensitive effect on its communications. In particular, communication failures in underwater communications occur more frequently because of a narrow bandwidth, slow transmission speed, noises from the surrounding environments and so on. In cases of communication failures, the sensor data can be lost in the sensor data delivery process and these kinds of sensor data losses can make critical huge physical damages on human or environments in applications such as fire surveillance systems. For this reason, although a few of studies for storing and compressing sensor data have been proposed, there are lots of difficulties in actual realization of the studies due to none-existence of the framework using network communications. In this paper, we propose a framework for reducing loss of the sensor data and analyze its performance. The our analyzed results in non-framework application show a decreasing data recovery rate, T/t, as t time passes after a network failure, where T is a time period to fill the storage with sensor data after the network failure. Moreover, all the sensor data generated after a network failure are the errors impossible to recover. But, on the other hand, the analyzed results in framework application show 100% data recovery rate with 2~6% data error rate after data recovery.

Effects of Korean Red Ginseng on White Matter Microstructure and Cognitive Functions : A Focus on Intrusion Errors (고려 홍삼이 대뇌 백질 미세구조 및 인지기능에 미치는 효과 : 침입 오류를 중심으로)

  • Jeong, Hyeonseok S.;Kim, Young Hoon;Lee, Sunho;Yeom, Arim;Kang, Ilhyang;Kim, Jieun E.;Lee, Junghyun H.;Ban, Soonhyun;Lim, Soo Mee;Lee, Sun Hea
    • Korean Journal of Biological Psychiatry
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    • v.22 no.2
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    • pp.78-86
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    • 2015
  • Objectives Although ginseng has been reported to protect neuronal cells and improve various cognitive functions, relationship between ginseng supplementation and response inhibition, one of the important cognitive domains has not been explored. In addition, effects of ginseng on in vivo human brain have not been investigated using the diffusion tensor imaging (DTI). The purpose of the current study is to investigate changes in intrusion errors and white matter microstructure after Korean Red Ginseng supplementation using standardized neuropsychological tests and DTI. Methods Fifty-one healthy participants were randomly allocated to the Korean Red Ginseng (n = 26) or placebo (n = 25) groups for 8 weeks. The California Verbal Learning Test was used to assess the number of intrusion errors. Intelligence quotient (IQ) was measured with the Korean Wechsler Adult Intelligence Scale. Depressive and anxiety symptoms were evaluated using Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, and Hopkins Symptom Checklist-25. The fractional anisotropy (FA) was measured from the brain DTI data. Results After the 8-week intervention, Korean Red Ginseng supplementation significantly reduced intrusion errors after adjusting age, sex, IQ, and baseline score of the intrusion errors (p for interaction = 0.005). Change in FA values in the left anterior corona radiata was greater in the Korean Red Ginseng group compared to the placebo group (t = 4.29, p = 0.04). Conclusions Korean Red Ginseng supplementation may be efficacious for improving response inhibition and white matter microstructure integrity in the prefrontal cortex.

A Study of The Determinants of Turnover Intention and Organizational Commitment by Data Mining (데이터마이닝을 활용한 이직의도와 조직몰입의 결정요인에 대한 연구)

  • Choi, Young Joon;Shim, Won Shul;Baek, Seung Hyun
    • Journal of the Korea Society for Simulation
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    • v.23 no.1
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    • pp.21-31
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    • 2014
  • In this article, data mining simulation is applied to find a proper approach and results of analysis for study of variables related to organization. Also, turnover intention and organizational commitment are used as target (dependent) variables in this simulation. Classification and regression tree (CART) with ensemble methods are used in this study for simulation. Human capital corporate panel data of Korea Research Institute for Vocation Education & Training (KRIVET) is used. The panel data is collected in 2005, 2007, and 2009. Organizational commitment variables are analyzed with combined measure variables which are created after investigation of reliability and single dimensionality for multiple-item measurement details. The results of this study are as follows. First, major determinants of turnover intention are trust, communication, and talent management-oriented trend. Second, the main determining factors for organizational commitment are trust, the number of years worked, innovation, communication. CART with ensemble methods has two ensemble CART methods which are CART with Bagging and CART with Arcing. Comparing two methods, CART with Arcing (Arc-x4) extracted scenarios with very high coefficients of determination. In this study, a scenario with maximum coefficient of determinant and minimum error is obtained and practical implications are presented. Using one of data mining methods, CART with ensemble method. Also, the limitation and future research are discussed.

Evaluation of Lung Dose Using Linac Photon Beam in Geant 4 Simulation (Geant4 Simulation에서 Linac 광자선을 이용한 폐 선량평가)

  • Jang, Eun-Sung;Lee, Hyo-Yeong
    • Journal of the Korean Society of Radiology
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    • v.12 no.4
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    • pp.443-450
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    • 2018
  • The Geant 4 simulated the linear accelerator (VARIAN CLINAC) based on the previously implemented BEAMnrC data, using the head structure of the linear accelerator. In the 10 MV photon flux, Geant4 was compared with the measured value of the percentage of the deep dose and the lateral dose of the water phantom. In order to apply the dose calculation to the body part, the actual patient's lung area was scanned at 5 mm intervals. Geant4 dose distributions were obtained by irradiating 10 MV photons at the irradiation field ($5{\times}5cm^2$) and SAD 100 cm of the water phantom. This result is difficult to measure the dose absorbed in the actual lung of the patient so the doses by the treatment planning system were compared. The deep dose curve measured by water phantom and the deep dose curve calculated by Geant4 were well within ${\pm}3%$ of most depths except the build-up area. However, at the 5 cm and 20 cm sites, 2.95% and 2.87% were somewhat higher in the calculation of the dose using Geant4. These two points were confirmed by the geometry file of Genat4, and it was found that the dose was increased because thoracic spine and sternum were located. In cone beam CT, the dose distribution error of the lungs was similar within 3%. Therefore, if the contour map of the dose can be directly expressed in the DICOM file when calculating the dose using Geant4, the clinical application of Geant4 will be used variously.

Shipboard Fire Evacuation Route Prediction Algorithm Development (선박 화재시 승선자 피난동선예측을 위한 알고리즘 개발 기초연구)

  • Hwang, Kwang-Il;Cho, So-Hyung;Ko, Hoo-Sang;Cho, Ik-Soon;Yun, Gwi-Ho;Kim, Byeol
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.5
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    • pp.519-526
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    • 2018
  • In this study, an algorithm to predict evacuation routes in support of shipboard lifesaving activities is presented. As the first step of algorithm development, the feasibility and necessity of an evacuation route prediction algorithm are shown numerically. The proposed algorithm can be explained in brief as follows. This system continuously obtains and analyzes passenger movement data from the ship's monitoring system during non-disaster conditions. In case of a disaster, evacuation route prediction information is derived using the previously acquired data and a prediction tool, with the results provided to rescuers to minimize casualties. In this study, evacuation-related data obtained through fire evacuation trials was filtered and analyzed using a statistical method. In a simulation using the conventional evacuation prediction tool, it was found that reliable prediction results were obtained only in the SN1 trial because of the conceptual and structural nature of the tool itself. In order to verify the validity of the algorithm proposed in this study, an industrial engineering tool was adapted for evacuation characteristics prediction. When the proposed algorithm was implemented, the predicted values for average evacuation time and route were very similar to the measured values with error ranges of 0.6-6.9 % and 0.6-3.6 %, respectively. In the future, development of a high-performance evacuation route prediction algorithm is planned based on shipboard data monitoring and analysis.

Longitudinal Change in Health Status after the Sewol Ferry Accident among Bereaved Parents (세월호 참사 후 희생자 부모의 건강상태 변화)

  • Yang, Sang Eun;Tae, Hye Jin;Hwang, Jihyun;Chae, Jeong-Ho
    • Anxiety and mood
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    • v.14 no.1
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    • pp.44-52
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    • 2018
  • Objective : The present study had examined the psychiatric symptoms and physical health consequences for the bereaved parents of the high school students who died in the 2014 Sewol ferry accident. Methods : Forty bereaved parents participated in the study. The authors administered self-report questionnaires about the parents' health behaviors and psychiatric symptoms. The authors also conducted laboratory tests to assess the parents' physical health at 18 and 30 months after the accident. Univariate descriptive statistics were performed to report the prevalence and severity of psychiatric symptoms and health-related behaviors. Paired t-test and Mcnemar test were performed to compare the 18-and 30-month findings. Correlation analysis between psychiatric symptoms and laboratory findings were performed to find a relationship between the two variables. Results : At 30 months after the accident, most of the bereaved parents still appeared to suffer from complicated grief (97.5%), post traumatic stress disorder (80%), insomnia (77.5%) and severe depression (62.5%) based on the scores on the Inventory of Complicated Grief (ICG), the PTSD Check List-5 (PCL-5), the Insomnia Severity Index (ISI) and the Patient Health Questionnaire-9 (PHQ-9). One quarter of the bereaved parents reported high-risk drinking, and 47.5% reported increased drinking amount and frequency after the accident. In objective laboratory results, 55% of the bereaved parents were obese as defined by body mass index ${\geq}25$. The parents' mean low-density lipoprotein shows a significant increase over time (118.5 mg/dL at 18 months. vs. 132.5 mg/dL at 30 months. paired t-test t=-4.061, $$p{\leq_-}0.001$$). Total cholesterol and low-density lipoprotein at 30 months after the accident were in clinically borderline high range. In correlation analysis, triglyceride was positively correlated with ISI. Conclusion : The loss of children in the Sewol ferry accident, a disaster caused by human error, continued to have considerable impact on the victims' parents' mental and physical health 18 and 30 months after the accident. A longitudinal study following the parents' physical health would be necessary to investigate the long-term effects of this traumatic experience on physical health.