• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.133-144
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• 2004

A model and a measure which can evaluate the risk of rear end collision are developed. Most traffic accidents involve multiple causes such as the human factor, the vehicle factor, and the highway element at any given time. Thus, these factors should be considered in analyzing the risk of an accident and in developing safety models. Although most risky situations and accidents on the roads result from the poor response of a driver to various stimuli, many researchers have modeled the risk or accident by analyzing only the stimuli without considering the response of a driver. Hence, the reliabilities of those models turned out to be low. Thus in developing the model behaviors of a driver, such as reaction time and deceleration rate, are considered. In the past, most studies tried to analyze the relationships between a risk and an accident directly but they, due to the difficulty of finding out the directional relationships between these factors, developed a model by considering these factors, developed a model by considering indirect factors such as volume, speed, etc. However, if the relationships between risk and accidents are looked into in detail, it can be seen that they are linked by the behaviors of a driver, and depending on drivers the risk as it is on the road-vehicle system may be ignored or call drivers' attention. Therefore, an accident depends on how a driver handles risk, so that the more related risk to and accident occurrence is not the risk itself but the risk responded by a driver. Thus, in this study, the behaviors of a driver are considered in the model and to reflect these behaviors three concepts related to accidents are introduced. And safe stopping distance and accident occurrence probability were used for better understanding and for more reliable modeling of the risk. The index which can represent the risk is also developed based on measures used in evaluating noise level, and for the risk comparison between various situations, the equivalent risk level, considering the intensity and duration time, is developed by means of the weighted average. Validation is performed with field surveys on the expressway of Seoul, and the test vehicle was made to collect the traffic flow data, such as deceleration rate, speed and spacing. Based on this data, the risk by section, lane and traffic flow conditions are evaluated and compared with the accident data and traffic conditions. The evaluated risk level corresponds closely to the patterns of actual traffic conditions and counts of accident. The model and the method developed in this study can be applied to various fields, such as safety test of traffic flow, establishment of operation & management strategy for reliable traffic flow, and the safety test for the control algorithm in the advanced safety vehicles and many others.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.4
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• pp.383-395
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• 2008

The grouting is one of the improved techniques which is aim to decrease the permeability and to strengthen the soft ground. But The grouting method has many problems about a suitability of grouting procedure and an effectiveness of grouting after grouting work because of a technical characteristic operated inside the soil. The grouting $p{\sim}q{\sim}t$ chart of a typical index about grouting rate and time alteration of grouting pressure is one method to estimate the suitability of grouting factor with monitoring during grouting procedure. This study is automatic grouting system (AGS) which can control the testing and grouting procedures. It can make the detailed $p{\sim}q{\sim}t$ chart and analyze the grouting characters of the ground by comparing the detailed pattern of $p{\sim}q{\sim}t$ chart with standard pattern. If using the $p{\sim}q{\sim}t$ chart derived from AGS in the grouting work, it is an objective standard estimating the suitability of grouting factor with grouting materials, grouting method, grouting rate and grouting pressure, as results it expects successfully to improve reliability of the grouting work.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.6
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• pp.563-580
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• 2010

In 2009 the Korea Ministry of Environment announced 'A Comprehensive Plan for the Improvement of Sewer Service in Rural Area' aiming at reduction of the sewer service gap between urban and rural areas as well as improvement in the residential environment of the rural area. According to the plan, the sewer system supply rate for the rural area is expected to reach up to 75% until 2015 with the budget of 4.7 trillion won (Korean currency). It is not certain, however, that the increase in the sewer system supply rate will accompany improvement of water quality in receiving water because several veiled problems that can occur in small-scale sewer treatment plants are poorly addressed in the plan. In this study, those issues for the small-scale sewer treatment plants and their solutions were discussed based on a case study in which we investigated 19 treatment facilities at two rural regions in Gyeonggi province. This study also included strategies useful for the plan. From the results of investigation, some problems, e.g., high hourly variations but low in flowrates and low mass loading were commonly identified. Although operation parameters in sewer treatment plants require to be modified depending on the mass loading, most of the plants were operated with the initial design parameters which causes the decrease of removal efficiency. In the intensive diagnosis, we arranged and applied solutions (e.g., flow equalization, air on/off time control, etc) to the two selected plants and found out improvement of effluent water quality, especially organic matters (COD and SS) and T-N with better denitrification performance.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.863-870
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• 2012

The market trends of automatic meter reading associated with smart water meters were investigated. Also, recent developments and field applications of key technology for automatic meter reading associated with smart water meters were analyzed. Smart water meters have been manufactured mostly in United States and Europe and have been expanded their business to Asia. Integrated water management system combining with the additional functions such as real-time consumption metering, cost notification, water conservation, leak detection, water quality monitoring, and flow control have been operated in automatic meter reading. Both water quality and quantity data measured from smart water meters and sensors were transferred to data concentration units through neighborhood area network, and then were transferred to integrated server through wide area network. The data transfer methods were determined by comprehensively considering urban scale, density of smart water meters, power supply and network topologies. Common data collection methods such as fixed network to data concentation units, vehicles drive by, people walk by, and drone fly by have been applied. The automatic meter reading associated with smart water meters are spread throughout the world, and both water and energy savings result in saving the money and reducing the greenhouse gases emission.

• Journal of Convergence Society for SMB
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• v.2 no.1
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• pp.51-58
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• 2012

Android platform is a powerful operating system developed on Linux 2.6 Kernel, and provides many features such as comprehensive libraries, a multimedia environment, and powerful interface for phone applications. Since Android is an open operating system, which can be installed in any vendors's equipments. Current smartphones as well as netbooks, navigations, car PCs, tablet PCs, Industrial PCs are used in various fields. It is difficult a lot that to mount to other devices on the Android platform or new devices. In this Paper, The process that data that occurred from a hardware was passed to the highest application and Android platform system for managing hardware devices were analyzed. Building Android & driver compilation environment, How to support the protocol for the use of WiFi in the kernel, How to Mount a WiFi device in the kernel, Device driver registration for the Android platform, WiFi Management Service Daemon (wpa_supplicant) and IP allocation services daemon (dhcpcd) registration, How to create a socket for communication between the daemon (wpa_supplicant) and HAL have been presented. In the experiment using the proposed method, WiFi devices were mounted on the Android platform in the X-86 & ARM family. Understanding the whole process of control flow in Android hierarchy is very important to porting a new device on it. The process included in this paper can help technicians who might encounter the obstacles in their porting works.

• Journal of Society of Preventive Korean Medicine
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• v.4 no.1
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• pp.32-50
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• 2000

On the process of research in the plan on oriental medical participation in the industrial health sponsored by BK21 project, we carried out the oriental medical health examination program for workers during former half-year We reached the conclusion as follows, 1. The oriental medical health examination program is contents and formalities that should be determined by present industrial health system, based on the oriental medical system and scholastic character, and included probability of the western and oriental medical cooperation. 2. The oriental medical health examination program can promote capability of individual health management and productive power of workers, and it is capable to manage on the self-conscious symptoms and macroschophically approach to their environment 3. The oriental medical health examination program that we have developed, is flow as questionare, understanding of working environment, information of result and later management. It is composed of three fields as follow , first, use of pulse diagnostic apparatus, understanding of the health promotion life style, and diagnosis of the oriental medical doctor, second, analysis of constitution, third, photographing for understanding of the musculoskeletal disorders, questionare for musculoskeletal self-conscious symptoms, and diagnosis of oriental medical doctor. 4. The oriental medical health examination program that we have developed, progressive from the view point of health, makes the oriental medical doctor's roll more important. It is the first trial at the western and oriental medical cooperation and characterized by excellence about musouloskeletal disorders. But it need to be improved in aspects of time and specialist on the health examination, diagnostic apparatus, control of examinant and later management. So we think that it needs research on the employment of health examination specialist, establishment of later management system, development of significantly diagnosable standard and assessable form on the health examination, and contents of health examination on the western and oriental medical cooperation.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.2
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• pp.1-17
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• 2015

Ecological reservoir is a multifunctional space where provides the functions of retention, animal habitat and improvement of ecosystem health and landscape. The ecological reservoir of Anteo Eco Park located in Gwangmyeong-si has established to functions for water purification, maintenance of healthy aquatic ecosystem. Because the Anteo Eco Park is located in the site where nonpoint pollutant materials flow in, Anteo Eco Park has potential factors which aquatic ecosystem health deteriorates and damages the habitat of golden frog(Rana plancyi chosenica) which is restoration target species. Therefore, the purpose of this study is to suggest the plan to manage the variables which impede the right functions of aquatic ecosystem by understanding the causal loop diagram for the change of water quality environment and the interaction of predator-prey through system thinking. The results are as follows. First, the study showed that the individual number of golden frog which is an indicator species of Anteo Eco Park is threatened by snakeheaded fish, which is an upper predator. Therefore, balanced food chain should be hold to protect golden frog by capturing the snakeheaded fish which is individual number's density is high, and the monitoring management of the individual number for predator(snakeheaded fish)-prey(golden frog) should be performed. Second, the study represented that water pollution and carnification is caused by the sediment as the dead body of the large emergent vegetation in the winter cumulates as sediment. Ecological reservoir in Anteo Eco Park has been managed by eliminating the dead body of the large emergent vegetation, but the guideline for the proper density maintenance of vegetation community is additionally needed. Lastly, the study showed that aquatic ecosystem of Anteo Eco Park where is contaminated from the inflow of nonpoint pollutants affects the individual number's decline of golden frog and snakeheaded fish. Accordingly, the creation of a buffer area and a substitution wetland is needed in the periphery of the Anteo Eco Park to control the inflow of nonpoint pollutants including organic matters, nutrients and heavy metals. This study will be helpful that Anteo Eco Park improves the regional landscape and maintain healthy aquatic ecosystem space for the park visitors including local residents.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.503-516
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• 2021

Autonomous fire detection and suppression system requires advanced technology for complex detection technology and injection/control technology for accurate hitting by fire location. Also, foam spraying should be included to respond to oil fires. However, when a single spray monitor is used in common, water and foam spray properties appear different, so for accurate fire suppression, research on the spray trajectory and distance will be required. In this study, experimental studies and numerical analysis studies were combined to analyze the foam spray characteristics through the spray monitor developed for the establishment of an autonomous fire extinguishing system. For flow analysis of foam injection, modeling was performed using OpenFOAM analysis software, and the commonly used foaming agent (Aqueous Film-Forming Foam) was applied for foam properties. The injection distance analysis was performed according to the injection pressure and the injection angle according to the form of the foam, and at the same time, the results were verified and presented through the injection experiment.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.6
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• pp.519-525
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• 2023

The human brain constantly emits electrical impulses, which is called brain waves, and brain waves can be defined as the electrical activity of the brain generated by the flow of ions generated by the biochemical interaction of brain cells. There is a study that emotion is one of the factors that can cause stress. Brain waves are the most used in the study of emotions. This paper is a study on whether emotions affect stress, and showed two images of fear and joy to four experimenters and divided them into three stages before, during, and after watching. As a measurement tool, brain waves at the positions of Fp1 and Fp2 were measured using the NeuroBrain System, a system that can automate brain wave measurement, analysis, brain wave reinforcement, and suppression training with remote control. After obtaining the brain wave data for each emotion, the average value was calculated and the study was conducted. As for the frequency related to stress, the values of Alpha and SMR, Low Beta, and High Beta were analyzed. Brainwave analysis affects stress depending on the emotional state, and "fear" emotions cause anxiety by raising Beta levels, resulting in higher Mind Stress levels, while "joy" emotions lower Beta levels, resulting in a significant drop in Mind Stress.

• Korean journal of food and cookery science
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• v.19 no.2
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• pp.195-209
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• 2003

The purpose of this study was to identify the hazard analysis critical control point on food production and transportation flow, applied to home-delivered meals for the elderly. To carry out this study, 1) pan-fried oak mushroom and meat, soy sauce glazed hair tail, and roasted dodok were selected as high nutrient and preferred foods for the elderly and 2) time, temperature, and microbiological quality(standard plate count, coliform, Salmonella spp, Vibrio parahaemolyticus, Staphylococcus spp., Escherichia coli O157:H7, and Listeria monocytogenes) were measured at various phases of the home-delivered meal production and its transportation flows. The results of this experiments are as follows: The temperature measured at cooling phases during the home-delivered meal production flows was 19.2 ∼ 20.0$^{\circ}C$ for the pan- fried oak mushroom and meat and the roasted dodok and was 24.0 ∼ 25.2$^{\circ}C$ for the soy sauce glazed hair tail. These temperature were in the potentially dangerous zone. Microbiological analysis showed that S. spp. was higher in the raw ingredients, including oak mushroom, hair tail, radish, and dodok, than the standard limit. SPC was lower than the standard limit from cooking to transportation phase, but SPC increased significantly during the cooling and packaging phase. The level of coliform detected was far lower than the standard limit and was not detected at all during the transportation phase. Few S. spp. was detected in the pan-fried oak mushroom and meat, but was found in above standards limit during the wrap packaging phase in the soy sauce glazed hair tail and roasted dodok. The level decreased rapidly during the holding and transportation phase. Sal. spp., V. parahaemolyticus, S. spp., E. coli O157:H7, and L. monocytogenes were not detected. For the pan-fried oak mushroom and meat, the critical control points were during the purchasing and receiving of raw ingredients, cooling, and packaging phases. For the soy sauce glazed hair tail and roasted dodok, the critical control points were during the purchasing and receiving of raw ingredients, preparation, cooling, and packaging phases.