• Journal of the Korea Institute of Building Construction
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• v.6 no.2 s.20
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• pp.81-89
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• 2006

A down construction method is frequently used in these days to reduce popular discontent and to assure sufficient working space at early stage in downtown area. There are two main problems in the existing down construction method. One is a confliction between frame works and excavation works, and the other is a cold joint in retaining wall which is unavoidable due to a sequence of concrete placement and induces a water leakage. Therefore, a new method is needed to overcome these problems. The CWS (buried wale Continuous Wall System) method was developed by authors. By replacing RC perimeter beam with embedded steel wale, the steel frame works of substructure can be simplified and the water leakage can be prevented using continuous retaining wall. Consequently, the improved qualify and reduction of construction period can be obtained from CWS method.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.4
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• pp.290-297
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• 2013

The increasing level of operation in high-tech industry is likely to require ever more complex structure in reliability problem. Furthermore, system failures are more significant on society as a whole than ever before. Reliability redundancy optimization problem (RROP) plays a important role in the designing and analyzing the complex system. RROP involves selection of components with multiple choices and redundancy levels for maximizing system reliability with constraints such as cost, weight, etc. Meanwhile, previous works on RROP dealt with system with perfect failure detection, which gave at most a good solution. However, we studied RROP with imperfect failure detection and switching. Using absorbing Markov Chain, we present not a good solution but the optimal one. In this study, the optimal system configuration is designed with warm and cold-standby redundancy for k-out-of-n system in terms of MTTF that is one of the performance measures of reliability.

• The Korean Journal of Pain
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• v.6 no.1
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• pp.129-132
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• 1993

Paraplegia complicating a block of the celiac plexus with alcohol for recurrent stomach cancer is described. A 33 year old male patient was admitted to control for severe epigastric pain. With the patient in prone position, the needle was advanced further than 2 cm on the anterior margin of $L_1$ vertebral body under fluoroscopy. 3 ml of 1% lidocaine and 5 ml of conray were injected through each needle, and the diffusion of the contrast medium was checked, This was followed by 7 ml of pure alcohol and 8 ml of 50% alcohol for each needle. At that time, the patient was very satisfied with loss of abdominal pain. About 30 minutes after injection of alcohol, suddenly patient complained of severe burning pain on back and both extremities. Thereafter, loss of sensation and paralysis in both extremities were developed slowly. The senstivity to cold recovered 3 days after block. By the 33rd day after the block, sensation had recovered in both extremities, the bladder and rectum. Movement of the right ankle joint and left great toe was also possible.

• Journal of The Korean Dental Society of Anesthesiology
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• v.11 no.1
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• pp.45-50
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• 2011

Bell's palsy is an isolated facial paralysis of sudden onset caused by a neuritis of the seventh nerve within the facial canal. It occurs often in the adult man with a history of recent exposure to local cold, such as sleeping next to an open window, or in some cases it occurs after infections of the nasopharynx or masticator spaces. Especially, this neuropathy have linked with the major collagen disorders (diabetes mellitus). A segmental demyelination develops rapidly, with vascultitis in microinfarcts and ischemia to the nerve segment. The authors experienced about the bizarre neurological symptom of Bell's palsy after inferior alveolar nerve block anesthesia and TMJ dislocation in diabetic mellitus. The early and correct consultation with the multiple medical and dental departments was important to prevent the inadequate care & medicolegal problems.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.307-310
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• 2008

In the framework of COMS(Communication, Ocean and Meteorological Satellite) programme, the first bipropellant propulsion system for GEO satellite has been developed successfully. So far Korea has its own experience of development of a monopropellant propulsion system for LEO satellites, i.e., KOMPSAT's. Other types of propulsion systems for a satellite, such as cold gas and electric propulsion etc., are being developed somewhere in Korea, however they are not commercialised yet, apart from those two systems aforementioned. This paper mainly focused on the design of the Chemical Propulsion System(CPS) for the COMS, joint scientific and communications satellite. It includes descriptions of the general system design and a summary of the supporting analysis performed to verify suitability for space flight. Essentially it provides an overview and guide to the various engineering rationale generated in support of the COMS CPS design activities. The manufacture and subsequent testing of COMS CPS are briefly discussed. Feasibility of COMS CPS to an interplanetary mission is proposed as well.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.5
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• pp.27-34
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• 2018

Concrete placed under hot weather condition suffers from larger slump loss, rapid moisture evaporation due to high air temperature. Proper measures for material, transportation and curing should be taken to prevent the quality deterioration of the concrete under hot weather condition. In Korea, Although the period of hot weather concrete in Korea occupies only 2 months, there are a lot of quality problems including plastic, drying shrinkage and cold joint. Therefore, the objective of this paper is to investigate and compare the temperature history and crack occurrence of the concrete, which was placed in the actual apartment house construction field under hot weather condition, in response to the application of surface covered curing blankets including PE film, single layer clear bubble sheet, white colored bubble sheet and aluminum metalized bubble sheet. Test results indicated that the application of white colored bubble sheet and aluminum metalized bubble sheet showed most favorable results in terms of reduction in temperature rise and crack occurrence as well as easiness in handling. But, due to light reflection by aluminum metalized bubble sheet, it is believed that white colored bubble sheet is preferable.

• Journal of Korean Society of Steel Construction
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• v.17 no.5 s.78
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• pp.581-591
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• 2005

This paper proposes a design formulae that evaluates the design strength of T-joints made of cold-formed square hollow steel sections with longitudinal branch plate. The T-joints had a configuration that a branch member used to longitudinal plate to the main chord in the plane. This study focused on the branch plate T-joints governed by the main chord flange failure mode among the experimental results. Based on the test results of the longitudinal branch plate T-joint in the square hollow sections, the ultimate strength on the T-joints was defined as 1.5 times the load at 1% B the strength of joints that governed the serviceability in control for $16.7{\leq}2\gamma(B/T){\leq}31.3$ and $0.20{\leq}{\beta}(b1/B){\leq}0.75$. Existing yield line models for normal T-joints were investigated to be the main chord flange failure for the branch plate T-joint, and this proposal design formula was based on the theory of the yield line model. Finally, the value of the finite element method compared with the value of the test and theory for the T-joints verified the validity of the design formulae.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.365-372
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• 2004

The purpose of this study was to implement HACCP system to foodservice of W and D elementary schools with joint-lunch management system in Kyungsan area. Steamed rice with squid was selected and Control Action, Monitoring Procedure and Control measure were identified based on HACCP flowchart to produce safe and healthy food. It was suggested that frozen squid must be thawed under the cold running city water and kept temperature below 1$0^{\circ}C$ and receiving/thawing procedure has to be done within 30 min. Raw vegetables must be washed under three-tube wash stand and whole prepreparation procedures should be done in 20 minutes. Clean and sanitize all the equipment and utensils before and after handling squid. Knives and cutting boards for vegetable and squid should be classified. Sauce for steamed rice with squid should be heated about 21 minutes to reach the temperature of 94$^{\circ}C$ before serving and internal temperature of food must be kept above 84.4$^{\circ}C$ during serving. The ideal temperature of kitchen should be remained 15∼18$^{\circ}C$. The underground water has to be excluded to minimize the risk of contamination in the foodservice facility and the prepreparation place must be separated with cooking place. Also, Personal hygiene Practice should be check in each stage. Further, additional research needs to be conducted to determine models for HACCP implementation for different menu.

• Journal of Korean Society of Steel Construction
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• v.21 no.5
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• pp.451-459
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• 2009

The purpose of this study was to evaluate the in-plane bending moment for T-joints made of cold-formed square hollow steel sections. In the previous studies, the T-joint was shown not to have an obvious peak load, and the failure mode was the main chord flange failure at the branch-width-to-chord-width ratio ($\beta$) of below 0.71. Based on the experimental results, including the tests conducted by Zhao, the deformation limit of 1% B was proposed for ${16.7{\leq}2{\gamma}(=B/T){\leq}33}$ and ${0.34{\leq}{\beta}(=b_{1}/B){\leq}0.71}$. Then, the ultimate in-plane bending strength was shown to be Mu=1.5${\cdot}$M1% B. The existing strength formulae for the original T-joint were investigated and were determined to be the main chord flange failure for the branch-squared T-joint. The bending strength formulae of CIDECT and other researchers were compared with the test results. Finally, a reasonably good agreement with Zhao's formula was found. Therefore, the design guidelines were presented based on Zhao's strength formula for T-joints.

• Journal of Biomedical Engineering Research
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• v.19 no.6
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• pp.617-622
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• 1998

A cryotherapy system using cold air was developed. The developed system had superior low-temperature characteristics with various flow rates and nozzle sizes, and used R-404A, as a coolant, which has no destructive effects of Ozone layers. Flow rates and the treatment time can be easily altered during the operation. In addition, and alarm system was designed for the overload, overheat, and over-charge of the machine. For clinical applications, skin temperatures, intra-articular temperatures of the knee joint and intra-muscluar temperatures of the gluteal muscles were measured during and after the cryotherapy. After a 5-minute therapy, skin and intra-articular temperatures decreased by $23.3{\pm}4.7 and 4.1 {\pm}1.0^{circ}C$, respectively. A 5-minute cryotherapy was good enough to maintain low intra-articular temperatures for 2-3 hours. Resting intra-muscular temperatures in 2, 4, and 6cm deep in the gluteal muscle were $36.5{\pm}1.2, 36.9{\pm}0.2, 37.1{\pm}0.2^{circ}C$, respectively (p<0.05). Lowest temperatures in 2, 4, and 6cm depth were $35.1{\pm}0.7, 36.2{\pm}0.4, 36.9{\pm}0.3^{circ}C$, respectively (p<0.05). Temperatures after a 2-hour cold air application on the skin and in the muscle in dept도 of 2, 4, and 6cm were $32.2{\pm}1.1, 36.2{\pm}0.5, 36.6{\pm}0.3, 36.9{\pm}0.3^{circ}C$respectively (p<0.05). Temperatures on the skin and in the muscle significantly decreased after 2 hours, compared with before cold air application (p<0.05). The intra-muscular temperature was changed more slowly than the skin temperature, and the deeper the muscle, the lesser temperature changes. The effect of a 5-minute cold air application lasts up to 2 hours, and it seems that the rebound-rise of the temperature dut to the reactive vasodilatation does not occur in the gluteal muscle.