• Journal of Soil and Groundwater Environment
• /
• v.22 no.6
• /
• pp.74-84
• /
• 2017

Soil erosion is often extreme in Korea due to high rainfall intensities and steep slopes, and climate change has also increased the risk of erosion. Despite its significane, erosion-induced soil organic carbon (SOC) emission and water resource loss are not well understood, along with the lack of an integrated surface soil erosion protection policy. Therefore, to design adequate protection policies, land users, scientists, engineers and decision makers need proper information about surface soil and watershed properties related to greenhouse gas emission potential and water conservation capability, respectively. Assuming the total soil erosion of $346Tg\;yr^{-1}$, soil organic matter (SOM) content of 2% (58% of SOM is SOC), and mineralization rate of 20% of the displaced carbon, erosion-induced carbon emission could reach $800Gg\;C\;yr^{-1}$. Also the available water capacity of the soil was estimated to be 15.8 billion tons, which was 14 times higher than the yearly water supply demand in Seoul, Korea. Therefore, in order to prevent of soil erosion, this study proposes a three-stage plan for surface soil erosion prevention: 1) classification of soil erosion risk and scoring of surface soil quality, 2) selection of priority areas for conservation and best management practices (BMP), and 3) application of BMP and post management.

• Journal of Wetlands Research
• /
• v.9 no.1
• /
• pp.107-114
• /
• 2007

This study aimed to investigate the hexachlorobenzene (HCB) dechlorinating ability of sediment microbes collected from a natural canal receiving secondary effluents from an industrial estate and nearby factories. Nine sites along the stream and one in the estuary in the Gulf of Thailand into which the canal spills were specified and sampling for sediment and water. Preliminary analysis of the sediments showed that the first four sites nearest to the discharging location were contaminated by HCB within the range of 0.18 to 1.25 ppm. Apart from that, 1,3,5-trichlorobenzene which has never been commercially produced or used in any manufacturing processes except for the transformation from higher chlorinated benzene was also identified in the range of 0.16 to 0.24 ppm. This suggested a possibility of sporadically HCB contamination in this stream. Of more important, people in the community along this canal earn their living by coastal fishery; hence, posing a risk of spreading HCB and its less chlorinated congeners via food chain from caught marine creatures to human. As a result, there is an urgent need to understand the behavior of HCB dechlorination in this stream sediment which can lead to a clean-up action in the future. Serum bottles with sediment slurries (sediment to water ratio of 1:1 (v/v) and filtered to remove particles larger than 0.7 mm) from each site were inoculated with 2 mg/l of HCB, kept anaerobically in the dark at room temperature without any nourishment, and analyzed for HCB and its less-chlorinated congeners every 6 days. Total chemical oxygen demand, suspended solids, and volatile suspended solids were in the range of 21,492-73,584, 158,100-518,100 and 6,000-32,700 mg/l, respectively. It was found that all sediment slurries began to dechlorinate HCB in 12 to 30 days and the HCB was completely removed within 42 to 60 days or so. On the other hand, there was no HCB dechlorination occurred in the controlled set which was sterilized by autoclaving prior to the addition of HCB. This implies that the HCB transformation was solely due to microorganisms' activities. HCB was dechlorinated principally via pentachlolobenzene to 1,2,3,5-tetrachlorobenzene and terminated at 1,3,5-trichlorobenzene which is the major pathway as reported by many researchers. Dichlorobenzene has not been detected in any samples within the dechlorination period of 60 days. The results indicate that the microbial matrix in the sediment of this stream has an outstanding capability to dechlorinate HCB. Existing substrates and nutrients which mainly sorbed onto the solid phase and the typical temperature in Thailand were sufficient and suitable to promote the activities of these HCB-dechlorinating microbes.

• Journal of Korean Public Health Nursing
• /
• v.21 no.2
• /
• pp.134-145
• /
• 2007

Purpose: To test the effects of health education on the blood pressure, knowledge, and self-care of visiting nursing clients. Methods: The study subjects were 96 participants who had been diagnosed with hypertension or had high risk factors for hypertension among those registered at a public health center in Seoul. The education program was individualized and delivered to enhance the management of hypertension including life-style modification, medication, and complication managements. Data were collected using questionnaires from May to December 2006 and analyzed using descriptive analysis, t-test, paired t-test, and ANOVA. Results: The blood pressure of the participants after the education was significantly decreased compared to before the education. Education also significantly affected the increases of knowledge of the disease and self-care capability. However, the blood pressure and self care were not significantly improved for the age group over 85 years. Conclusions: This study proves that the individualized health education for visiting nursing clients was effective in improving blood pressure, knowledge, and self-care of hypertension. However, it is necessary to develop strategies that are specifically targeted at particular age groups in order to improve the capability of self-care of hypertension.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.26 no.4
• /
• pp.973-983
• /
• 2016

It's been almost 6 years since PIA was implemented based on legislation. So I analyzed problems of PIA from the perspective of ITSM 3 elements. I mainly took account of quality improvement of the report when I assessed systems processing personal informations. So, I propose in terms of logical validity improvement of assessment report. The improvements on 4 different outputs for each phase are many cases that I assessed systems processing personal informations. And I propose improvements on qualified assessors having capability of GRC and on process for managing the assessment system. To settle down PIA system as the reasonable and effective assessment system even after 2016, the statutory deadline for completion of PIA, assessors and appointed assessment firms and authorities should cooperate to complete the assessment system.

• Journal of the Korean Society of Systems Engineering
• /
• v.10 no.2
• /
• pp.21-31
• /
• 2014

Recently, global market competition of iron and steel products is ever increasing due to over-supply from increased number of industries in rapidly growing countries, such as China, Brazil, and Indonesia. To occupy the big market, major industries are trying to develop high quality, high performance steel products via developing a new iron and steel making process. In other words, development of a new and innovative steel plant is a key to cope with the tough situation. Design and development for the life cycle of iron and steel making plant is very much complex and multi-disciplinary. In this paper, Plant Systems Engineering (PSE), a tailored SE process for industrial plant based on ISO/IEC 15288 is used for the design of Continuous Casting Process (CCP) Plant system. The CCP is a crucial process in steel making plant, whose design technology is occupied by the advanced foreign companies. For the sake of increasing engineering capability for the design of CCP, we applied PSE Process for the renovation of the existing CCP Process. Through the study, we were convinced that the applied method can be used for other plant systems, and SE is really the way of thinking, design, and development of modern complex and multi-disciplinary systems where high risk factors are present throughout the whole life cycle.

• Nuclear Engineering and Technology
• /
• v.48 no.4
• /
• pp.881-892
• /
• 2016

Following the Fukushima accident and its extended station blackout, attention was brought to the importance of the spent fuel pools' (SFPs) behavior in case of a prolonged loss of the cooling system. Since then, many analytical works have been performed to estimate the timing of hypothetical fuel uncovery for various SFP types. Experimentally, however, little was done to investigate issues related to the formation of a flammable gas mixture, distribution, and stratification in the SFP building itself and to some extent assess the capability for the code to correctly predict it. This paper presents the main outcomes of the Experiments on Spent Fuel Pool (ESFP) project carried out under the auspices of Swissnuclear (Framework 2012-2013) in the PANDA facility at the Paul Scherrer Institut in Switzerland. It consists of an experimental investigation focused on hydrogen concentration build-up into a SFP building during a predefined scaled scenario for different venting positions. Tests follow a two-phase scenario. Initially steam is released to mimic the boiling of the pool followed by a helium/steam mixture release to simulate the deterioration of the oxidizing spent fuel. Results shows that while the SFP building would mainly be inerted by the presence of a high concentration of steam, the volume located below the level of the pool in adjacent rooms would maintain a high air content. The interface of the two-gas mixture presents the highest risk of flammability. Additionally, it was observed that the gas mixture could become stagnant leading locally to high hydrogen concentration while steam condenses. Overall, the experiments provide relevant information for the potentially hazardous gas distribution formed in the SFP building and hints on accident management and on eventual retrofitting measures to be implemented in the SFP building.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.3
• /
• pp.1489-1494
• /
• 2013

Tsunami happens rarely enough to allow a false sense of security, but when they do occur, there may be just minutes or hours for people to reach a safe location. Natural disasters like tsunami are inevitable and it is almost impossible to fully recoup damages caused by the disasters. However, it is possible to minimize the potential risk by developing early warning strategies. GIS modelling with its geoprocessing and analysis capability can play a crucial role in efficient mitigation and management of disaster. This study aims at developing integrated spatial information system processing model supporting tsunami evacuation action planning using geo-information technology such as GIS. The integration process classified into four phases. And in each phase, required input data and GIS processes are decided. The main effort in minimizing casualties in tsunami disaster is to evacuate people from the hazard area before tsunami strikes by means of either horizontal or vertical evacuation. The study provides essential spatial information for local decision making related with people's evacuation in tsunami-prone areas based on a modeling approach transferable to other coastal areas.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.49 no.10
• /
• pp.829-839
• /
• 2021

Autonomous system for UAVs has a capability to decide an appropriate current action to achieve the goal based on the ultimate mission goal, context of mission, and the current state of the UAV. We propose a decision-making system that has an ability to operate ISR mission autonomously under the realistic limitation such as low altitude operation with high risk of terrain collision, a set of way points without change of visit sequence not allowed, and position uncertainties of the objects for the mission. The proposed decision-making system is loaded to a Hardware-In-the-loop Simulation environment, then tested and verified using three representative scenarios with a realistic mission environment. The flight trajectories of the UAV and selected actions via the proposed decision-making system are presented as the simulation results with discussion.

• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.18 no.2
• /
• pp.87-100
• /
• 2022

Unit capacity factor (utilization rate) of nuclear power plants (NPPs) is an important performance indicator. Since the first commercial operation of Kori Unit 1 began in April 1978, the utilization rate of domestic NPPs has gradually increased, reaching 90% from the end of the 1990s. However, due to various issues such as the Fukushima accident in 2011, corrosion of the CLP, the utilization rate dropped to 65~80%. In the early 1980s, the utilization rate of the U.S. NPPs was around 60%. However, since 2004, it has been consistently maintained above 90%. Therefore, in this study, we first examined the causes of declining the utilization rate in domestic NPPs. Next, the significances of the utilization rates are reviewed in five aspects: investment capability, electricity rate, safety and export, etc., with discussion on the current status of the utilization rates in the U.S. Based on this, three key factors are derived as the reasons of the increasing: equipment reliability program, on-line maintenance and the pursuit of institutional rationality. And finally, by synthesizing above results, the measures for increasing the utilization rate of domestic NPPs are proposed in terms of equipment management, institutional improvements, and personnel resources.

• The Korean Journal of Community Living Science
• /
• v.17 no.3
• /
• pp.159-174
• /
• 2006

The purpose of this study is to provide information searching for health promotion, nutrition improvement, and health care of the impaired elderly by ADL(Activity of Daily Living) and IADL(Instrumental Activity of Daily Living). The subjects were divided into the Assistant Needed Group and No Assistant Needed Group for living in line with the responses of ADL(10 items like dressing, washing, move etc.) and IADL(10 items like housekeeping, using transportation, shopping, Phone call etc.). Survey was made for health behavior, health risk habit, dietary management status and diet intake by 24 hr-recall and questionnaire method. 242 subjects were collected in 12 cities or Gun districts in Gyeonggi Province, S. Korea. Survey was carried out by regional home extension workers using interview method. Statistical analyses were made using SAS (Version 8.1). Chi-Square Tests and General Linear Models. The subjects of impaired ADL elderly was 26.5% and it composed 30% of the total male and 22.2% of the total female. The demographic status of the impaired ADL elderly showed no difference from that of the normal elders, elementary school educated (73.4%), with spouse (43.8%) or with adult children(37.5%), using monthly living cost of 500-1,000 thousand won(35.9%). Mean age was 74.05 years compared to 72.25 years of normal elders. However, there was no significant difference from the normal and impaired ADL group, regular exercise(60.0%), with walking (90.0%), no-smoke(54.7%) and no-drink(48.4%). Kind of disease was not different from the one in impaired and normal group, with cardiovascular disease(32.3%), with diabetes mellitus(8.1%), joint lumbago neuralgia(32.3%) and osteoporosis(9.7%). Gastrointestinal complaints of the impaired ADL group were nausea(57.8%), chronic indigestion (23.4%), constipation (14,0%) and vomiting(3.7%). Sleeping time required for the impaired was longer than that for the normal group by 10hours(4.7%) or 8-10hours(20.3%), which consisted 1.7% and 16.6% respectively. Nutrient intake of the impaired ADL group was low compared to normal range elders: Energy(1260kca1), Protein(52.75g). There was gender difference in nutrient intake; the male impaired group showed no significant difference from the normal group but it was significantly lower in female impaired group. These results suggest that low quality of life and low economic status of the impaired ADL elderly require congregate meal in village hall to cover the lack of side dishe variety. And nutrition education program including community assistance would be required for the impaired ADL elderly together with the sufficient food and exercise practice. By operating nutrition education program, the impaired ADL elderly would maintain more enhanced quality of life and ameliorate the ADL capability.