• Journal of Environmental Science International
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• v.13 no.10
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• pp.911-919
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• 2004

The purpose of this research was evaluated economical effect to apply alternative external carbon source. Conventional activated sludge process in municipal wastewater treatment plant was adapted and introduced to Biological nutrient removal processes to meet the newly enforced effluent quality standard for nutrient removal in Korea. Low $COD/NH_4^+-N$ ratio and higher nutrient concentration of influent characteristics force to inject external carbon source for denitrifying recycled nitrate. In the most case, methanol was used as external carbon source. But Methanol is expensive and very dangerous in handling. So we could find cheaper and safer external carbon source substituted methanol in last study. This alternative external carbon source is named RCS(recoverd carbon source) and a by-product of fine chemical product at chemical plant. When RCS was applied real municipal wastewater treatment plant, average $55\~65\%$ of T-N removal efficiency, 8.8mg/l of effluent T-N concentration, 11.3mg/l of effleunt COD concentration were obtained without effluent COD increase as against used methanol. To apply RCS in municipal wastewater treatment plant obtain approximately $\74.5%$ expenditure cost reduction in comparison with methanol dosage cost.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.327-330
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• 2017

In recent years, Drone(lightweight unmanned aerial vehicle) is used for broadcast shooting, disaster scene, leisure, observation and military purposes. However, as the use of drones increases the threat of hacking is also rising. Especially when a flying drone is seized, a dangerous situation can occur which is abused regardless of the driver's intention. Already in Iran and China, there is a case of hacking and stealing the drones of other countries under reconnaissance. In this paper, we analyze the security vulnerabilities of Wi-Fi and Bluetooth communication in wireless network which are used in drones for stealing the commercial drones. The results provide a countermeasure to safeguard the drones against attempts by the unauthorized attacker to take out the drones.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.2
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• pp.165-171
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• 2013

WAVE(Wireless Access in Vehicular Environments) is a representative V2V communication protocol and its standards of MAC and PHY parts except for security were published. In order to control traffic flow and ensure driver's safety using V2V communication, various projects are conducting. In particular, safety application has been researched. Therefore, in this paper, we designed the safety application algorithm, which informs a driver of the dangerous status when driver tries to turn left in an intersection and we also implemented the algorithm. Proposed algorithm configures a model for a host vehicle and a vehicle coming in opposite lane and in case that there is collision hazard it provides warning message to driver by using HMI. In order to evaluate the proposed algorithm's performance, we configured the test bed using test vehicles and we tested the algorithm on proving ground with the composed test scenarios. As test results, our system showed excellent performance. If the infrastructures for V2I communications are constructed, we will optimize our system more precisely and stably.

• Journal of the Korean Society of Costume
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• v.61 no.8
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• pp.57-72
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• 2011

The purpose of this research is to develop a safe and convenient wearable technology wear for bikers. For this, we studied the current usage of two-wheeled vehicles and have also researched the rate of accidents and its causes. We then used them along with previous studies in terms of visual perception as factors to decide the crucial elements of the riders' apparel. Case studies and the break down for the established prototypes for bikers were practiced as well. Based on this process, a survey was conducted to find out the needs of the bikers in the areas of both apparel and technology and then proceeded to produce the appropriate design and device modules. In the apparel sector, the result of the survey indicated that it was considerable that any digital devices were not shown to sustain a natural visible look. It also was essential that the materials were durable and made for safety and easy movement. In the digital function sector, it was significant that a motion input interface which will be embedded into the wear was needed to avoid any dangerous situations. This would ensure the safety of not only the rider but the surrounding riders as well. Lastly, protecting the rider's skin from any harmful elements was regarded necessary as well. Based on these requirements, a new prototype was created and will be tested if the requirements stated above are all met and will be evaluated according to the effectiveness of its functions.

• Journal of Korean Tunnelling and Underground Space Association
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• v.4 no.1
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• pp.37-43
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• 2002

Recently, the construction of tunnels longer than one kilometer has increased rapidly. Considering characteristic of limiting structure of longer tunnel, if fires inside tunnel broke out because of vehicle incidents, the catastroph would have high possibility to take place due to toxic smoke and heat of fire. In case of highway tunnel, safety facilities which can cope with tunnel fire are installed in the tunnel but according to rapid increase of heavy good traffic, dangerous goods and enlargement of tunnel magnitude, the research has to carry out about heat fluxes and smoke behaviour during tunnel fire. Therefore, through full-sized fire experiment the paper analyzed temperature distribution, wind velocity, smoke behaviour during tunnel fire.

• Journal of the Korea Society for Simulation
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• v.15 no.1
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• pp.11-17
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• 2006

This paper shows a case study of designing a PLC logic simulator that was developed to simulate and verify PLC control programs for nuclear plant systems. The nuclear control system requires strict restrictions rather than normal process control system does, as it works with a high-risky and dangerous nuclear plant. One is that it should assure the safeness of the control programs by exploiting severe testing. The other restriction is that the control programs should be executed fast enough such that they could control multi devices concurrently in real-time. To cope with these restrictions, we devised a logic compiler which generates C-code programs from given PLC logic programs. Once the logic program was translated into C-code, the program could be analyzed by conventional software analysis tools and could be used to construct a fast logic simulator after cross-compiling, in fact, that is a kind of compiled-code simulator.

• Clinical and Experimental Reproductive Medicine
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• v.35 no.2
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• pp.163-167
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• 2008

Ovarian hyperstimuation syndrome (OHSS) is the most serious complication of controlled ovarian stimulation. It causes symptoms such as, ovarian enlargement, ascites, pleural effusion, pericardial effusion, hemoconcentration, electrolyte imbalance, and thromboembolism. Although proper management is done, thromboembolism could occur and is difficult to predict. Moreover it can cause death. Consequently thromboembolism is the most dangerous complication of OHSS. We experienced a OHSS patient with thromboembolism of the brain after having IVF-ET.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.2
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• pp.122-134
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• 2020

To improve traffic congestion, reduce fuel consumption, and improve the stability of truck operations, truck platooning, in which several trucks are organized in a single platoon, is being actively researched globally. Compared to the operation of a single truck, the operation of a truck platoon requires more caution before the actual operation because an accident of one vehicle in the platoon can lead to an accident with all the vehicles in the platoon. Therefore, this study examined the types of trucks and cargo suitable for truck platooning to prevent safety accidents. The review showed that a closed-van-type truck is appropriate for truck platooning to prevent falling objects during driving. In the case of cargo types, it is necessary to exclude liquids and dangerous goods defined in related laws from truck platooning.

• Geotechnical Engineering
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• v.9 no.4
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• pp.55-64
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• 1993

The Undrained creep tests on the normally consolidated clays with four different consolication ratios(c3c'/clc': 1.0, 0.7, 0.5, 0.4) were performed to investigate the effects of avisotropic consolidation on the undrained creep rupture behavior. The elapsed time to a certain minimum strain rate is decreased with decreasing the value of the consolidation pressure ratio, and the elapsed time to rupture for a certain minimum strain rate is also decreased with decreasing the ratio. The upper yield strength obtained from the equation suggested by Finn and Shead(1.) is coincided well with the creep strength irrespective of the magnitude of the consolidation pressure ratio, and the normallised upper yielding strength by mean confining pressure is decreased with increasing the consolidation pressure ratio. The critical strain for creep rupture, the strain at min. strain rate, is constant irrespective of the magnitude of creep stress, but it increased exponentially with increasing the ratio, It accordingly is dangerous that the potential of in-situ creep rupture is estimated only by the creep rupture test on the isotropically consolidated clay in case of K0-value below 1.0.

• Journal of the Korean Institute of Rural Architecture
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• v.10 no.2
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• pp.61-70
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• 2008

The purpose of this study is to give some suggestions for the legal supplement of the regulation on the balcony expansion for the optimal use of apartment balcony. For the purpose, this study focused on the characteristics of spaces expanded to the balcony, in the plans supplied after the legalization of balcony expansion, comparing them by their location; the metropolitan area of Seoul Gyeonggi and the districts of the other areas. The 168 plans of apartments in the supplied by top 10 constructors in the metropolitan areas of Seoul and Gyeonggi, together with the 92 plans in the other smaller districts in 2006 to 2007 were analyzed with the tools of frequency and chi-square analysis. The result is as follows. (1) The region showed no difference in the plans of balcony; whereas the size, the position and access of the shelter explained some differences of balcony plan. (2) In wider plans, balconies were placed in all sides of plan-front, rear and side, and were remodeled to expand facing rooms. (3) The balcony expansion tended to increase the number of bays. (4) In almost cases, the living rooms were expanded to balcony. In smaller plans, the balconies were remodeled to supply supplementary kitchen space, splitting it from laundry. (5) The shelters were placed at the rear or side of plans, but the shelter facing room could be dangerous in case of fire. The balcony expansion, despite of legalization spirit to adopt diverse use of additional spaces for residents' needs, was only a tool for the space expansion. The amendment of the regulation is needed to accommodate these findings that the balconies should be identified by their function, that the front corridor-type balcony should be limited in length and magnitude, and that the shelter should be positioned with easy access.