• Journal of Energy Engineering
• /
• v.27 no.2
• /
• pp.1-13
• /
• 2018

The proportion of natural gas-fueled power generation is expanding due to the change of domestic energy policy pursuing reduction of dust and increasing clean energy consumption. Natural gas fuels used for the combined-cycle power plants and the district-heating power plants are operated at high temperature and high pressure in the fuel supply system. Accidents due to leakage of the gas such as fire and explosion should be prevented by applying risk management techniques. In this study, risk assessment was performed on the natural gas fuel supply system of a combined power plant based on the API RP 581 RBI code. For the application of the API RBI code, lines and segments of the evaluation target system were identified. Operational data and input information were analyzed for the calculations of probability of failure and consequence of failure. The results of the risk assessment were analyzed over time from the initial installation time. In the code-based evaluation, the gas fuel supply system was mainly affected by thinning, external damage, and mechanical fatigue damage mechanisms. As the operating time passes, the risk is expected to increase due to the external damage caused by the CUI(Corrosion Under Insulation).

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.7
• /
• pp.539-547
• /
• 2017

This study examined the perception of disasters and post-traumatic stress disorder in occupational therapy majors to provide the basic data necessary for future occupational therapy. A questionnaire survey was conducted on 545 students in occupational therapy departments of three year and four year universities. The frequency of the questionnaire was calculated by frequency analysis using the SPSS 19.0 win program. A chi-squared test was conducted to verify the analyzed questionnaire data. The reliability of the questionnaire in this study showed a Cronbach' alpha value of 0.891. According to the survey results, approximately 20% of learners who majored in occupational therapy were unaware of the symptoms, developmental mechanism, and diagnostic criteria of post-traumatic stress disorder(PTSD). Knowledge of the underlying causes of psychological symptoms, such as post-traumatic stress disorder as well as physical damage through industrial accidents, was found to be 2.92 on the Likert 5-point scale. To be effective in rehabilitation treatment, the degree of the approach to education from the viewpoint of occupational therapy is important enough to be recognized as 3.90 on the Likert 5-point scale. The Pearson correlation coefficient for the need for education on disasters was higher than the correlation with the awareness of disasters.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.4
• /
• pp.707-716
• /
• 2009

The levels of psychosocial stresses and fatigue of firemen were analyzed to reveal the various factors related to them. The self-administered questionnaires were performed to 262 firemen ill Cheonsju City. In terms of various levels of psychosocial stresses, 12.2% were under potential stresses, 87.8% were under high-level of stress, but healthy group was not found. The levels of fatigue symptoms divided by the median of total scores was 51.1% of low levels, and 48.9% of high levels. Multiple stepwise analysis revealed that the factors or influence on psychosocial stresses with explanatory powers of 11.5% included subjective health status, job satisfaction, job demand and alcohol drinking habits. The factors of influence on fatigue symptoms with explanatory powers of 9.0% included subjective health and regular exercises. The study results indicate that the level of stress or fatigue is so complicatedly influenced by variable factors. Thus the effective strategy for stress and fatigue reduction among firemen should include additional programs focusing on health promotion.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.8
• /
• pp.521-529
• /
• 2020

Forest fires are one of the most important environmental risks that have adverse effects on many aspects of life, such as the economy, environment, and health. The early detection, quick prediction, and rapid response of forest fires can play an essential role in saving property and life from forest fire risks. For the rapid discovery of forest fires, there is a method using meteorological data obtained from local sensors installed in each area by the Meteorological Agency. Meteorological conditions (e.g., temperature, wind) influence forest fires. This study evaluated a Data Mining (DM) approach to predict the burned area of forest fires. Five DM models, e.g., Stochastic Gradient Descent (SGD), Support Vector Machines (SVM), Decision Tree (DT), Random Forests (RF), and Deep Neural Network (DNN), and four feature selection setups (using spatial, temporal, and weather attributes), were tested on recent real-world data collected from Gyeonggi-do area over the last five years. As a result of the experiment, a DNN model using only meteorological data showed the best performance. The proposed model was more effective in predicting the burned area of small forest fires, which are more frequent. This knowledge derived from the proposed prediction model is particularly useful for improving firefighting resource management.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.11B
• /
• pp.1346-1356
• /
• 2011

Transportation has been playing important role in our society by providing for people, freight, and information. However, it cuts its own throat by causing car accidents, traffic congestion, and air pollution. The main cause of these problems is a noticeable growth in the number of vehicles. The easiest way to mitigate these problems is to build new road infrastructures unless resources such as time, money, and space are limited. Therefore, there is a need to manage the existing road infrastructures effectively and safely. In this paper, we propose a road reservation scheme that provides fast and safe response for emergency vehicles using ubiquitous sensor network. Our idea is to allow emergency vehicle to reserve a road on a freeway for arriving to the scene of the accident quickly and safely. We evaluate the performance by three reservation method (No, Hop, and Full) to show that emergency vehicles such as ambulances, fire trucks, or police cars can rapidly and safely reach their destination. Simulation results show that the average speed of road reservation is about 1.09 ~ 1.20 times faster than that of non-reservation at various flow rates. However, road reservation should consider the speed of the emergency vehicle and the road density of the emergency vehicle processing direction, as a result of Hop Reservation and Full Reservation performance comparison analysis. We confirm that road reservation can guarantee safe driving of emergency vehicles without reducing their speed and help to mitigate traffic congestion.

• KIPS Transactions on Computer and Communication Systems
• /
• v.6 no.6
• /
• pp.281-288
• /
• 2017

In Smart-cities, various types of integrated services must be linked to provide services to applications. Therefore, flexibility must be ensured between services so that various services can be efficiently provided. In order to secure the flexibility among services, it is very important to have a function to dynamically discover and invoke a desired service by searching for a semantic service by reflecting a recognized context through real-time context-aware in smart-cities. To date, quite a number of semantic service discovery techniques have been developed. However, they have not been verified as suitable for use in the smart-city domain. In this study, we tried to verify the existing ones to use a suitable one. We tested most of existing semantic service discovery techniques, but we found that none of them is suitable to our research. Therefore, we developed our own semantic service discovery technique. This paper introduces our work and presents the performance evaluation results that demonstrate that our developed works well and show good performance. For the performance evaluation, the experimental system was actually constructed and the real performance was measured. In the experiment, we implemented the semantic service discovery scenario that dynamically searches and calls the services needed to provide fire accident management services in smart cities.

• Food Science and Preservation
• /
• v.17 no.2
• /
• pp.230-235
• /
• 2010

We investigated the physicochemical quality characteristics of apple juice upon sterilization using hot water, and under various storage conditions. None of sugar content, acidity, or pH differed significantly among various sterilization conditions but chromaticity was considerably reduced in sterilized juice compared with control material. The chromaticity of non-sterilized juice decreased significantly after sterilization compared with material supplemented with vitamin C (0.1%, w/v). Fungi, yeast, and aerobic bacteria were detected in juice sterilized at $65^{\circ}C$ for 10 or 20 min, but no microorganisms were observed in juice sterilized by other procedures. Vitamin C content affected sterilization temperature to a greater extent than sterilization time. When juice was stored at $4^{\circ}C$ or $37^{\circ}C$ for 3 weeks after application of different sterilization conditions, almost no change in acidity, sugar content, or pH was observed, regardless of sterilization mode or storage period. However, chromaticity decreased with longer storage. Vitamin C levels were reduced by higher sterilization temperatures. However, longer storage periods had the greatest effect on reduction of vitamin C levels, which tended toward lower values regardless of differences in sterilization and storage conditions. In sensory evaluation tests, all of taste, color, and overall preference were highest for juice sterilized at $75^{\circ}C$ for 20 min. The ASC value was low at a storage temperature of $4^{\circ}C$ and at high sterilization temperatures, and a long storage period was associated with a greater ASC value. Thus, the quality of apple juice was excellent when juice was hot water-sterilized, with additional vitamin C, at $75^{\circ}C$ for 20 min, followed by storage at $4^{\circ}C$.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.26 no.1
• /
• pp.22-30
• /
• 2020

In March 2016, a 6.67-ton fishing boat capsized owing to the loss of stability during crane operations. Capsizing occurs when a boat or ship is flipped over (or turned upside down) for reason other than accidents caused by collisions, contact, stranding, fire or explosion. Over the past nine years (2010-2018), capsize accidents have accounted for 2.34 % of all marine accidents and are gradually increasing. The loss of stability from improper shipping is the main cause of most capsizes, especially for small fishing vessels weighing 10 tons. According to the Fishing Vessel Act, small fishing vessels weighing less than a ton are exempted from inspections on stability and load cranes. This study analyzes the issue cited as the reason for the capsizing of the small fishing boat in Goseong, namely, the reduction of restoring moment due to increased weight of the crane. Fishing boats with similar loading conditions were modeled on the basis of re-determination, and their stability before and after the accident was assumed. The fishing boats with heavier cranes were found to be at higher risk of capsizing owing to the reduction of the restoring moment and the angle of deck immersion. Under standard loading conditions, the stability moments of fishing vessels are lesser during fishing, compared to when they depart from or arrive at the port.

• Journal of Digital Convergence
• /
• v.15 no.6
• /
• pp.145-154
• /
• 2017

It is aimed to examine the effect of literary therapy program on the improvement of friendship among elementary school students using various media and activities of literature. After the literature therapy program was conducted for elementary students, post-test was conducted. The results of the study are as follows. First, there was no significant difference between the experimental group and the comparative group in the post-test immediately after the end of the program, but in the follow-up test performed 5 weeks after the counseling, the average of the peer relations of the experimental group was significantly higher than that of the comparative group. Second, in the post-test, there was no significant difference between the experimental group and the comparative group in the "intimacy" sub-area of the peer relationship, but in the follow- up test, the "intimacy" sub-region average of the experimental group was significantly higher than the comparative group. Third, the level of 'interest' among the peer relationship sub-domains of the experimental group showed a significant difference in the follow-up test. As a result, literature therapy had no immediate effect on the improvement of friendship among adolescents, but it was effective after a long time.

• Journal of Korean Society of Forest Science
• /
• v.76 no.3
• /
• pp.243-248
• /
• 1987

The U.S. Forest Service administers the world's largest forestry research organization. From its modest beginning in 1876, some 30 years before the United States national forest system was established, the research branch has devoted its effort to meet current and future information needs of the forestry community of the United States, not just for the U.S. Forest Service. The research branch is one of three major administrative units of the U.S. Forest Service. The others being the National Forest System and State and Private Forestry. Currently the National Forest System comprises 155 national forests, 19 national grasslands, and 18 utilization projects located in 44 states. Puerto Rico, and the Virgin Islands. The National Forest System manages these areas for a large array of uses and benefits including timber, water, forage, wildlife, recreation, minerals, and wilderness. It is through the State and Private Forestry branch that the U.S. Forest Service cooperates and coordinates forestry activities and programs with state and local governments, forest industries, and private landowners. These activities include financial and technical assistance in disease, insect, and fire protection ; plan forestry programs ; improve harvesting and marketing practices ; and transfer forestry research results to user groups. Forestry research is carried out through eight regional Forest Experiment Stations and the Forest Product Laboratory. Studies are maintained at 70 administrative sites, and at 115 experimental forest and grasslands. All of the current sciences that composed modern forestry are included in the research program. These range from forest biology (i. e. silviculture, ecology, physiology, and genetics) to the physical, mathematical, engineering, managerial, and social sciences. The levels of research range from application, developmental, and basic research. Research planning and priority identification is an ongoing process with elements of the research program changing to meet short-term critical information needs(i. e. protection research) to long-term opportunities(i. e. biotechnology). Research planning and priority setting is done in cooperation with National Forest Systems, forest industries, universities, and individual groups such as environmental, wilderness, or wildlife organizations. There is an ongoing review process of research administration, organization, and science content to maintain quality of research. In the U.S. Forest Service the research responsibility is not completed until the new information is being applied by the various user group : I. e. technology transfer program. Research planning and development in the U.S. Forest Service is a dynamic activity. Porgrams for the year 2000 and beyond are now in the planning stage.