• Journal of Korean Society for Atmospheric Environment
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• v.13 no.6
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• pp.463-474
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• 1997

Metallic elements in dustfall have been known as notable air pollutants directly or indirectly influencing human health and wealth. The first aim of this study was to obtain precise spatial distribution patterns of 5 elements (Pb, Zn, K, Cr, and Al) in dustfall around Suwon area. To predict isometric lines of metal fluxes deposited on unsupervised random sites, the study has applied both spatial statistics as a receptor model and a GIS (geographic information system). Total of 31 sampling sites were selected in the study area (roughly 3 by 3 km grid basis) and dustfall samples were then collected monthly basis by the British deposit gauges from Dec., 1995 to Nov., 1996. The metallic elements in the dustfall were then analyzed by an atomic absorption spectrometer (AAS). On the other hand, a base map overlapped by 7 layers was constructed by using the AutoCAD R13 and ARC/INFO 3.4D. Four different spatial interpolation and expolation techniques such as IDW (inverse distance weighted averaging), TIN (triangulated irregular network), polynomial regression, and kriging technique were examined to compare spatial distribution patterns. Each pattern obtained by each technique was substantally different as varing pollutant types, land of use types, and topological conditions, etc. Thus, our study focused intensively on uncertainty analysis based on a concept of the jackknife and the sum of error distance. It was found that a kriging technique was the best applicalbe in this study area.

• Tribology and Lubricants
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• v.36 no.6
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• pp.297-306
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• 2020

This paper reviews studies on the types and functions of oil sensors used for machine condition monitoring. Machine condition monitoring is essential for maintaining the reliability of machines and can help avoid catastrophic failures while ensuring the safety and longevity of operation. Machine condition monitoring involves several components, such as compliance monitoring, structural monitoring, thermography, non-destructive testing, and noise and vibration monitoring. Real-time monitoring with oil analysis is also utilized in various industries, such as manufacturing, aerospace, and power plants. The three main methods of oil analysis are off-line, in-line, and on-line techniques. The on-line method is the most popular among these three because it reduces human error during oil sampling, prevents incipient machine failure, reduces the total maintenance cost, and does not need complicated setup or skilled analysts. This method has two advantages over the other two monitoring methods. First, fault conditions can be noticed at the early stages via detection of wear particles using wear particle sensors; therefore, it provides early warning in the failure process. Second, it is convenient and effective for diagnosing data regardless of the measurement time. Real-time condition monitoring with oil analysis uses various oil sensors to diagnose the machine and oil statuses; further, integrated oil sensors can be used to measure several properties simultaneously.

• Nuclear Engineering and Technology
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• v.35 no.5
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• pp.412-425
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• 2003

According to the results of related studies, one of the typical factors related to procedure related human errors is the complexity of procedures. This means that comparing the change of the operators' behavior with respect to the complexity of procedures may be meaningful in clarifying the reasons for the operators' non-compliance behavior. In this study, to obtain data related to the operators' non-compliance behavior, emergency training records were collected using a full scope simulator. And three types of the operators' behavior (such as strict adherence, skipping redundant actions and modifying action sequences) observed from the collected emergency training records were compared with the complexity of the procedural steps. As the results, two remarkable relationships are obtained. They are: 1) the operators seem to frequently adopt non-compliance behavior to conduct the procedural steps that have an intermediate procedural complexity, 2) the operators seems to accommodate their non-compliance behavior to the complexity of the procedural steps. Therefore, it is expected that these relationships can be used as meaningful clues not only to scrutinize the reason for non-compliance behavior but also to suggest appropriate remedies for the reduction of non-compliance behavior that can result in procedure related human error.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.384-389
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• 2009

In general, gestures can be utilized in human-computer interaction area. Even though the acceleration information is most widely used for the detection of user’s intention, it is hard to use the information under the condition of zero or small variations of gesture velocity due to the inherent characteristics of the accelerometer. In this paper, a natural interaction method which does not require excessive gesture acceleration will be described. Taking advantages of the gravity, the system can generate various types of signals. Also, many problems such as initialization and draft error can be solved using restorative uprighting force of the system.

• Proceedings of the Safety Management and Science Conference
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• 2008.11a
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• pp.303-316
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• 2008

For the past 25 years, Korean semiconductor has experienced enormous growth to be the highest production country in the world. Semiconductor industry is very time sensitive and driven by technology and process, and requires 24-hour full operation. The environment includes many different types of equipment, utilities, different gases and toxic chemicals as well as high voltage electricity. We have performed a survey with 3-shift engineers and workers in one line. The content of the questionnaire was about the correlation between fatigue and performance shaping factor (work type and work ability), and as a result we were able to deduce the correlation, p-value and the pattern of scatter plot. The shape of the model was made of 4 blocks for fatigue, 5 blocks for work type and 5 blocks for work ability, i. e. 14 blocks in total. As a conclusion to this findings, there was a correlation between fatigue and work type and work ability specifically in semiconductor industry, and we need some effort to reduce this.

• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.67-78
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• 2015

The purpose of the establishment of corporation's Business Continuity Plan(BCP) is to maintain corporations' own business and establish the response plan in order to resume operation in a short time period when crisis situations occur due to natural disaster and human error. This study has presented all types of procedures and criteria which are needed to establish the airport crisis response system in order to maintain the business continuity by utilizing BCP technique. Basically the risk response procedures must be established in the process of (1) preparation stage, (2) plan development stage, (3) documentation stage, (4) test & maintenance stage. The guideline has been suggested that each stage must be carried out in the sequence of Policy & Planning Responsibility, Business Impact Analysis, Recovery Strategy & Plans, Emergency Plan & SOP, Training Awareness and Maintenance & Review

• Journal of Navigation and Port Research
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• v.38 no.5
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• pp.479-484
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• 2014

This paper presents the crew members fatigue survey in order to understand the current state of various fatigue causal factors and personnel fatigue subjective symptoms, and then analyzes the survey items. The results of this survey are as follows. Firstly, many crew members were struggling with the lack of sleep and rest hour. Secondly, environmental factors such as weather, ship motion and vibration, noise, accommodation condition etc. disturbed the sleep of crew members. In third, their duty hours were more than 10 hours per day in certain types of ship. In fourth, they felt fatigue a lot when they were on board because of the workload and stress. Lastly, in some measurement items of fatigue symptoms(physical, mental, emotional), many crew members were experiencing more than moderate fatigue symptoms.

• Journal of Internet Computing and Services
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• v.8 no.6
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• pp.155-167
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• 2007

There are four types of human beings according to the Sasang Typology, Oriental medical doctors frequently prescribe healthcare information and treatment depending on one's type, The feature ratios (Table 1) on the human face are the most important criterions to decide which type a patient is. In this paper, we proposed a system to extract these feature ratios from the people's side face, There are two challenges in acquiring the feature ratio: one that selecting representative features; the other, that detecting region of interest from human profile facial image effectively and calculating the feature ratio accurately. In our system, an adaptive color model is used to separate human side face from background, and the method based on geometrical model is designed for region of interest detection. Then we present the error analysis caused by image variation in terms of image size and head pose, To verify the efficiency of the system proposed in this paper, several experiments are conducted using about 173 korean's left side facial photographs. Experiment results shows that the accuracy of our system is increased 17,99% after we combine the front face features with the side face features, instead of using the front face features only.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4036-4044
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• 2012

This study is aimed to investigate the association between web-based visual stress and MBTI personality types. The stressor deriving visual stress is built by 14 vowels out of Korean alphabet as a content and parallel striples as a background on the screen, which is given to each subject during 5min. The dependent variable indicating how much human takes visual stress is the reduction rate of flicker fusion frequency, which is evaluated with visual flicker fusion frequency tester. The independent variables are gender and 8 MBTI personality types(E-I, S-N, T-F, and J-P), and hypotheses are based on human information processing model and previous studies. The results address that the reduction rate is not significantly affected by gender, S-N, and J-P, but E-I and T-F have significant influences on it. The reduction rate in I-type is almost 2 times as much as that in E-type and T-type has the rate 2.2 times more than F-type. This study can be applicable to determine the adequate personnel for jobs requiring less sensibility to visual stressors in areas that human error may lead to critical damages to an overall system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.1
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• pp.98-107
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• 2016

The purpose of this study is for Human error prevention to acquire Collision Risk Perception Index (CRPI) sensed by the Officer Of the Watch (OOW) when the approaching distances are reduced in six types of ship encountering situations (Head on, $045^{\circ}$, $090^{\circ}$, $135^{\circ}$, Overtaking, Overtaken) between own ship and a target ship and then to predict CRPI fitting coefficients with polynomials in the curve-fitting process. CRPI acquisition experiments are carried out on two coast-guard ships and with the total of 30 crew members. Analysing results shows that CRPI data have goodness of fit to the six types of encountering situation. Futhermore, the One-Way ANOVA results show that CRPI has a negative affect to the OOW's age, career and license grade as the approaching distances is reduced. The availability of CRPI curve fitting with 3 degrees of polynomial was testified through the RMSE as 1.19 to Head on, 0.87 to $045^{\circ}$, 0.81 to $090^{\circ}$, 0.71 to $135^{\circ}$, 1.29 to Overtaking and 0.87 to Overtaken.