• Journal of the Korean Solar Energy Society
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• v.36 no.6
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• pp.25-35
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• 2016

In this study, the evaluation of the dynamic behavior and thermal performance of the "Façade integrated Natural circulation Solar Water Heating System" installed in the residential house was carried out. Experimental tests were performed during the all year around in the rural houses of $166m^2$ in size. Facade integrated solar collector of $5m^2$ were installed on the south-facing. Electrical heater of 1 kW capacity as an auxiliary heater was installed at the upper part of the heat storage tank. The analyzing results are as follows. (1) Monthly average solar fraction was 51 to 87% and yearly average value is 64%. (2) Hot water supply temperature in December which has the lowest solar altitude is 37 to $76^{\circ}C$. The highest working fluid temperature of solar collector in this period was below $84^{\circ}C$. The temperature difference of working fluid between the collector inlet and outlet has been shown to be around 9 to $26^{\circ}C$. (3) Overheating which is one of the biggest problems during summer did not appear at all, but rather had hot water supply temperature is rather low as $30{\sim}47^{\circ}C$ in summer than winter, which is supplied by a small solar load. The solar collecting temperature has been shown to maintain below $55^{\circ}C$. (5) The thermal performance of Facade integrated solar collector can be increase due to the reduction of heat loss to the back of the collector wall integration of the collector is reduced. As a conclusion, Facade integrated natural circulation type Solar Water Heating System is a well-functioning without any pumps or controllers, and it was found that the disadvantages of conventional solar water heaters, hot water or hot water system can be greatly improved.

• Journal of the Korean Institute of Gas
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• v.22 no.5
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• pp.62-71
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• 2018

According to own investigation conducted by Korea Gas Safety Corporation Gas Safety Research Institute in 2017, the length of underground pipes in domestic high-pressure gas pipelines is approximately 770km, of which 84% is buried in Ulsan and Yeosu industrial complexes. In particular, 56% of underground pipelines have been in operation for more than 20 years. This suggests urgent management of buried high pressure gas pipelines. PHMSA in US and EGIG in Europe, major causes of accidents in buried gas pipelines are reported as third party damage, external corrosion and loss of pipe wall thickness. Therefore, it is important to evaluate whether the defects affect the remaining life of the pipe when defects occur in the pipe. DNV and ASME have evaluated the residual strength of pipelines through the hydraulic rupture test using pipe specimens with artifact flaws. Once the operating pressure is known through the residual strength of the pipe, the wall thickness at the point at which the pipe ruptures is calculated. If we know the accurate rate of corrosion growth, we can predict the remaining life of pipe. In the study, we carried out experiments with A53 Grade.B and A106 Grade.B, which account for 80% of domestic buried pipes. In order to modify the existing model equation, specimens with a defect depth of 80% to 90% was tested, and a formula expressing the relationship between defect and residual strength was made.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.3
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• pp.88-98
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• 2011

Masonry structure is a style of building which has been widely applied as residential facilities of low and middle stories, commercial and public facilities etc. But it is possible to destroy by loss of adhesive strength or sliding when lateral forces, such as earthquake, occurs. This study proposes a seismic retrofit method for masonry structure and its seismic performance is demonstrated by shaking table test. Two specimens per each shaking direction were made, having out-of-plane(weak axis) and in-plane(strong axis) direction. External load of 1 ton was also applied for each specimen during the test, to model the behavior of reinforced masonry wall. As a result of shaking table tests, it is shown that the specimen applying the proposed seismic retrofit method showed acceptable behaviors in both of Korea building design criteria(0.14g) and USA seismic criteria suggested by IBC(0.4g). However, it was observed that stiffness of the specimen toward out-of-plane was rapidly decreasing when seismic excitations over 0.14g were loaded. In comparison of relative displacements, maximum relative displacement of specimens which were accelerated toward out-of-plane with 0.4g at once was 29~31% of maximum relative displacement when specimens were gradually accelerated from 0.08g to 0.4g, while the maximum relative displacement of specimens accelerated toward in-plane has similar value in both cases. Therefore, it is concluded that the wall accelerated toward out-of-plane is more affected by hair crack or possible fatigues caused by seismic excitation.

• Journal of Digital Convergence
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• v.16 no.1
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• pp.147-152
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• 2018

Recently, as the demand for transmission of ultra-high quality media data such as UHD, AR, and VR increases, various technologies for this have been actively developed and IEEE 802.11ad standard have been commercialized. In this paper, a test bed is constructed to analyze the indoor wireless environment using the IEEE 802.11ad standard based on mmWave, and the experimental results of various indoor wireless environments are introduced and analyzed. We compared the data from the module by data transmission, such as signal to noise ratio(SNR) and throughput. And we measured the beam pattern and width of the module and compared the effects on the indoor environment of the corridor and the office. This shows that the signal reflection of the wall shows higher SNR values and is more suitable to use for indoor than outdoor. It is confirmed that the loss when not in line of sight(LoS) is not enough to compensate the wall reflected signal. As a result, it is judged to be suitable for the indoor use of the mmWave LAN and can be usefully used for further experiments.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.2
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• pp.193-204
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• 1984

The enzymatic properties of the alkaline AL-protease, which had been prepared from the crude zymolyase of Arthrobzoter luteus, was investigated together with its active amino acid residue. Complete inactivaton of the proteolytic activity of AL-protease by either DFP or PMSF was simultaneously accompanied by the loss of its lytic effect on the lysis of yeast cell wall. In the reaction, AL-protease showed the pattern of inactivation to decrease very slowly, as compared to that of chymotrypsin, and that enzyme and DFP were found to react with a molar ratio of 1 : 1. The preparation of AL-protease exhibited no hydrolytic activity in any substrates of polysaccharases, playing a significant role in the lysis of yeast cell wall. The optimum pH and temperature of AL-protease was pH 10.5 and $65^{\circ}C$, respectively. It also showed stability in the pH range from 5 to 11 and at the temperature below $65^{\circ}C$. Through the identification of the amino acid residue in the active site of the $^{32}P$-diisopropylph-osphorylated(DIP) AL-protease modified specifically with $^{32}P$-labeled DFP, AL-protease was found to be a DFP-sensitive which has a mole of active serine residue involved in its proteolytic activity per mole of the enzyme.

• Journal of Periodontal and Implant Science
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• v.38 no.1
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• pp.97-102
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• 2008

Purpose: Periodontal intrabony defects have great deal of importance since they contribute to the development of periodontal disease. Current treatment regimens for intrabony defects involve grafting of numerous bony materials, GTR using biocompatible barriers, and biomodification of root surface that will encourage the attachment of connective tissue. Xenograft using deproteinized bovine bone particles seems to be very convenient to adjust because it doesn't require any donor sites or imply the danger of cross infections. These particles are similar to human cancellous bone in structure and turned out to be effective in bone regeneration in vivo. We here represent the effectiveness of grafting deproteinized bovine bone particles in intrabony defect and furcation involvements that have various numbers of bony walls. Materials and methods: Open flap debridement was done to remove all root accretions and granulation tissue from the defects within persisting intrabony lesions demonstrating attachment loss of over 6mm even 3 months after nonsurgical periodontal therapy have been completed. Deproteinized bovine bone particles($BBP^{(R)}$, Oscotec, Seoul) was grafted in intrabony defects to encourage bone regeneration. Patients were instructed of mouthrinses with chlorohexidine-digluconate twice a day and to take antibiotics 2-3 times a day for 2 weeks. They were check-up regularly for oral hygiene performance and further development of disease. Probing depth, level of attachment and mobility were measured at baseline and 6 months after the surgery. The radiographic evidence of bone regenerations were also monitored at least for 6 months. Conclusion: In most cases, radio-opacities increased after 6 months. 2- and 3-wall defects showed greater improvements in pocket depth reduction when compared to 1-wall defects. Class I & II furcation involvements in mandibular molars demonstrated the similar results with acceptable pocket depth both horizontally and vertically comparable to other intrabony defects. Exact amount of bone gain could not be measured as the re-entry procedure has not been available. With in the limited data based on our clinical parameter to measure pocket depth reduction following $BBP^{(R)}$ grafts, it was comparable to the results observed following other regeneration techniques such as GTR.

• Journal of Gastric Cancer
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• v.5 no.1
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• pp.47-51
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• 2005

Eosinophilic gastroenteritis is a rare clinicopathologic entity of unknown etiology with a variety of digestive symptoms. The pathogenesis is poorly understood. Diagnostic criteria include demonstration of eosinophilic infiltration of the affected bowel wall, lack of evidence of extraintestinal disease, and exclusion of various disorders that could mimic similar conditions. The disease might involve any area of the gastrointestinal tract from the esophagus to the rectum, but the stomach and the proximal small bowel are most commonly affected. The clinical features depend on which layer and site are involved. We report the case of a 59-year-old male patient with a 3-week history of post-prandial vomiting with malnutrition and weight loss. An abdominopelvic CT showed a gastric outlet obstruction with diffuse wall thickening, as with linitis plastica. Three gastrofiberscopic biopsies showed chronic gastritis. We carried out a radical total gastrectomy with D2 lymph node dissection. The pathologic report revealed a mural type eosinophilic gastritis with a marked hypertrophic scar formation at the proper muscle layer. We report this case with a brief review of the literature. (J Korean Gastric Cancer Assoc 2005;5:47-51)

• Plant Journal
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• v.13 no.2
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• pp.46-51
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• 2017

In this study, the boiler efficiency and the change of boiler combustion state with the burner operation of the uppermost layer of 870MW opposite fired coal boiler were measured. Test results showed that the boiler efficiency was high in the order of the uppermost layer simultaneous operation of the front and rear burners, the front burner, and the rear burner operation. When the front and rear burners were operated simultaneously, the heat absorption rate of water walls in the boiler furnace was uniform at four side, and the temperature deviation of the left and right steam on the convection front surface decreased. As the heat absorption rate of the boiler improved, the loss of boiler exhaust gas decreased and the coal supply amount decreased by 8 tons/hour compared to the operation of the rear burner. This will contribute not only to the reduction of fuel cost but also to the reduction of greenhouse gas emissions.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1983.05a
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• pp.19.2-19
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• 1983

A Clinical and bacteriologcal observation was performed 128 cases of chronic otitis media who had taken middle ear surgery at Dept. of otolaryngology of St. Benedict Hospital during the period of Feb. 1981 to Feb. 1983. The following results were obtained. 1) Among total 128 cases, male were 60 cases (46.9%) and female were 68 cases (53.1 %) and age distribution showed 48 cases (37.5 %) in 3rd decade, 37 cases (28.9 %) in 2nd decade and 27 cases (21.1 %) in 4th decade. 2) Site distribution were 71 cases (55.5%) in right, 57 cases (44.5 %) in left. 3) Degree of preoperative hearing loss were 64 cases (50%) in moderate, 32 cases (25% ) in mild, 27 cases (21.1 %) in severe and 5 cases (3.9%) were normal. 4) Central perforation were observed in 65 cases (50.8 %), total perforation in 44 cases (34.4 %), attic perforation in 12 cases (9.4 %) and marginal perforation in 7 cases (5.4 %). 5) Pathologic changes of middle ear and mastoid antrum showed granulation in 81 cases (63.3 %), cholesteatoma in 47 cases (36.7%). 6) The route of approach were 123 cases (96.1%) in postauricular, 3 cases (2.3%) in transmeatal and 2 cases (1.6 %) in endaural. 7) Type of operation were 53 cases (41.4 %) in intact canal wall tympanoplasty with mastoidectomy, 42 cases (32.8 %) in tympanoplasty without mastoidectomy, 23 cases (18%) in modified radical mastoidectomy and 10 cases (7.8%) in radical mastoidectomy. 8) Type of anesthesia were 95 cases (74.2 %) by local anesthesia, 33 cases (25.8 %) were by general anesthesia. 9) Among 93 specimens of culture, proteus (31.2%), staphylococcus (28.7%), pseudomonas (23.7 %), streptococcus (7.5 %) and etc. (8.7%) in order of frequency.

• Journal of the Society of Disaster Information
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• v.8 no.4
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• pp.362-375
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• 2012

Tourist hotels are equipped with facilities such as accommodation and restaurants, exercise, recreation. Unspecified guests, visitors and management of tourist hotels are very vulnerable on the casualties and property losses due to fire peril exist. In this study, we analysis that the fire statistics status of tourist hotels from 2001 to 2010. And the 15 cases of a large hotel fire are reviewed. The total number of fires on hotel are consist of a hotel rooms fire(33.2%), a restaurant kitchen fire(11.8%). And the major causes of the fire are an electrical fire (40.8%), a cigarette fire (14.5%) and a hot-work fire (9.2%). In case study, the fire wall defect and combustible materials are major fire loss causes for 10year. Each tourist hotels are needed a development of suitable fire risk management and a field operations. A hotel is required an active fire risk management on a preventive inspection, an education and training, and a preventive maintenance. It is necessary that a fire wall maintenance to prevent of the spread of a fire and a sprinkler installation of whole area to protect fire. And it is very important an emergency response for evacuation of guest, and operate emergency procedures on a fire or emergency situation.