• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.587-599
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• 2018

In building-integrated photovoltaic (BIPV) systems, power generation functions are integrated into building functions by installing solar modules in combination with building materials. While this integration appears to be attractive, a design method is needed to achieve maximum power generation. Previously, the influence of the design elements on power generation was analyzed by computer simulations and demonstration tools. On the other hand, problems remain due to the inaccuracy of power generation analysis and relationship analysis, and limited demonstration. To solve this problem, this paper proposed the use of an extended demonstration mock-up. The mock-up was designed and constructed by implementing the design elements of the module types, installation angles, and direction. The actual operation data for one year were analyzed to evaluate the effects of the design elements on power generation. These results can be used to determine the feasibility of future BIPV systems and the optimal selection of system design elements.

• Journal of Korean Neurosurgical Society
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• v.59 no.5
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• pp.492-497
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• 2016

Objective : Decompressive craniectomy is an effective therapy to relieve high intracranial pressure after acute brain damage. However, the optimal timing for cranioplasty after decompression is still controversial. Many authors reported that early cranioplasty may contribute to improve the cerebral blood flow and brain metabolism. However, despite all the advantages, there always remains a concern that early cranioplasty may increase the chance of infection. The purpose of this retrospective study is to investigate whether the early cranioplasty increase the infection rate. We also evaluated the risk factors of infection following cranioplasty. Methods : We retrospectively examined the results of 131 patients who underwent cranioplasty in our institution between January 2008 and June 2015. We divided them into early (${\leq}90days$) and late (>90 days after craniectomy) groups. We examined the risk factors of infection after cranioplasty. We analyzed the infection rate between two groups. Results : There were more male patients (62%) than female (38%). The mean age was 49 years. Infection occurred in 17 patients (13%) after cranioplasty. The infection rate of early cranioplasty was lower than that of late cranioplasty (7% vs. 20%; p=0.02). Early cranioplasty, non-metal allograft materials, re-operation before cranioplasty and younger age were the significant factors in the infection rate after cranioplasty (p<0.05). Especially allograft was a significant risk factor of infection (odds ratio, 12.4; 95% confidence interval, 3.24-47.33; p<0.01). Younger age was also a significant risk factor of infection after cranioplasty by multivariable analysis (odds ratio, 0.96; 95% confidence interval, 0.96-0.99; p=0.02). Conclusion : Early cranioplasty did not increase the infection rate in this study. The use of non-metal allograft materials influenced a more important role in infection in cranioplasty. Actually, timing itself was not a significant risk factor in multivariate analysis. So the early cranioplasty may bring better outcomes in cognitive functions or wound without raising the infection rate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.1-9
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• 2020

Acritical function of a nation is to protect its people's lives and properties from natural disasters such as a drought. A drought affects many aspects of human life, including social, economic, and industrial activities. Approximately 75.7% of reservoirs in Korea are over 50 years old.Sedimentation over the years may have caused a situation where storage capacity of the reservoirs is no longer sufficient and compliant with the original reservoir specifications. This study analyzes storage capacities for ten aged reservoirs using the autonomous navigation USV. It compares these capacities with sediment estimated by conventional empirical equations. Comparisons were made to the original specifications for the reservoirs.Storage capacity of six reservoirs decreased in a range between 16.2%-55.3% and storage capacity of 4 reservoirs increased in a range between 1.5%-380.2%. This data was compared to data derived from estimating sediment by empirical equations. Yoon's equation(1982) appeared more accurate than Sur's equation(1988) in Uhlinzi and Yongpo reservoirs, and Sur's equation(1988), however, appeared more accurate than Yoon's equation in Daegok, Ugok2 and Ochi reservoirs. The significant ranges of sedimentation shown in this study suggest that it is worth continuously surveying reservoirs to ensure their efficient management and operation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.3
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• pp.21-29
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• 1985

An effective technique of sludge separation is required for concentrated activated sludge process. The dissolved-air flotation (DAF) has been shown to be efficient process for sludge separation. The factors affecting DAF process for activated sludge separation are type and concentration of sludge, air/solid ratio, ratio of pressurized water flow, pressure, sludge detention time, temperature, sludge and hydraulic loading rate, recycle flow rate of sludge and type and quantity of chemical aid. In order to study the optimal operation condition for sludge separation, the influence factors such as type and concentration of sludge, ratio of pressurized water flow and pressure are investigated by the batch and continuous reactor experiments of DAF and sedimentation test. By the experimental investigation, the results are as follows; 1. For the bulking and concentrated sludge, DAF is more effective than sedimentation for the sludge separation. 2. In DAF, the critical ratio of pressurized water flow exist. The critical value varies with the pressure in the tank. That is, according to the pressure changes from 3 to $5kg/cm^2$, the critical value varies from 0.25 to 0.67 accordingly. 3. Pressure affects the ratio of pressurized water flow, but it does not show any influence upon the DAF efficiency directly. 4. Continuous experimental results was not better than those of batch.

• Journal of Digital Convergence
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• v.18 no.10
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• pp.181-194
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• 2020

Due to the changes in the distribution market, issues related to storage and distribution of agricultural, aquatic and livestock products, and storage and transportation of processed and fresh food are rapidly emerging, and as a result, Cold Chain is naturally receiving attention as one of the logistics services. The purpose of this study is to evaluate the competitiveness of location in the construction of a cold chain cluster centered on the metropolitan area, which has attracted attention in relation to the distribution of cold chains, such as recently refrigerated frozen foods. To this end, this study evaluated the competitiveness of cold chain cluster candidates in the metropolitan area by utilizing the CFPR (Consistent Fuzzy Preference Relations) method that can efficiently extract and quantify expert knowledge. As a result, the location competitiveness was found to be superior to Incheon New Port's hinterland, Gyeonggi South Area (Yongin), Gyeonggi West Area (Gimpo Logistics Complex), and Pyeongtaek Oseong Logistics Complex. In particular, this study extracted the knowledge of refrigerated and refrigerated logistics warehouse operation experts, and conducted detailed competitiveness assessments for cold chain cluster candidates in the metropolitan area, and suggested the optimal cluster candidates. In the future research, it is necessary to classify the questionnaire into the owner, large business group, and public business group, etc., who have the right to purchase and build to secure ownership of the fresh food distribution center.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.6
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• pp.394-399
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• 2013

The recalcitrant hairs which are accumulated in the U-trap equipped to prevent the stench from the drainage produce the phenomenon of blocking the flow of water through the home drainage pathway. The chemical dissolution solutions commercially manufactured are excessively poured into U-trap to solve this blocking problem. In this study, the specially designed instrument was developed for the experiments to cut and crush the hairs of which main component are the recalcitrant keratin proteins. The performance of the instrument for cutting and crushing hairs was investigated using experimental methods. The cutting and weighing method was used in order to obtain the average length of a large amount of hairs cut by instrument. This method is relatively simple to measure the weight of cutting hairs to obtain the average length of the fibers, the values of average length showed not greater tolerances. Also the average cutting number was defined to evaluate the performance of the cutting and crushing instruments designed for this study. We were able to apply these evaluation methods to provide the criteria to obtain the optimal structure of instrument and proper operation time in the given experimental conditions. These experimental methods and results will provide the good example to design and to analyze the various device that can be used for cutting the fibers. The cutting and crushing instrument developed in this study showed the effective abilities to cutting the hairs. The general using the cuttting and crushing instrument at every home would be helpful to prevent water environmental pollution.

• Journal of Trauma and Injury
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• v.25 no.4
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• pp.115-121
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• 2012

Purpose: Severe pancreaticoduodenal injuries are relatively uncommon, but may result in high morbidity and mortality, especially when management is not optimal, and determining the appropriate treatment is often difficult. The objective of this study was to review our experience and to evaluate the role of a pancreaticoduodenectomy (PD) in treatment of pancreaticoduodenal injuries. Methods: We performed a retrospective review of 16 patients who underwent an emergency PD at our hospital for severe pancreaticoduodenal injury from 1990 to 2011. Demographic data, clinical manifestations, mechanism and severity of the injury, associated injuries, postoperative complications and outcomes were reviewed. Results: The mean age of the 16 patients was $45{\pm}12years$ ($mean{\pm}standard$ deviation), and 15(93.8%) patients were male. All patients underwent an explorative laparotomy after a diagnosis using abdominal computed tomography. Almost all patients were classified as AAST grade higher than III. Thirteen(83.3%) of the 16 patients presented with blunt injuries; none presented with a penetrating injury. Only one(6.3%) patients had a combined major vascular injury. Fifteen patients underwent a standard Whipple's operation, and 1 patient underwent a pylorus-preserving pancreaticoduodenectomy. Two of the 16 patients required an initial damage-control procedure; then, a PD was performed. The most common associated injured organs were the small bowel mesentery(12, 75%) and the liver(7, 43.8%). Complications were intraabdominal abscess(50%), delayed gastric emptying(37.5%), postoperative pancreatic fistula(31.5%), and postoperative hemorrhage (12.5%). No mortalities occurred after the PD. Conclusion: Although the postoperative morbidity rate is relatively higher, an emergency PD can be perform safely without mortality for severe pancreaticoduodenal injuries. Therefore, an emergency PD should be considered as a life-saving procedure applicable to patients with unreconstructable pancreaticoduodenal injuries, provided that is performed by an experienced hepatobiliary surgeon and the patient is hemodynamically stable.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.223-228
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• 2002

We have developed a homemade particle inflow gun (PIG) system which has simple operation method, low price and high gene introduction efficiency into rice callus. Rice callus were inflowed with gold particles containing DNA of a plasmid, pIG121Hm, harboring intron GUS ($\beta$-glucuronidase) gene, NPTII gene and HPT gene. For optimal GUS transient expression, the effects of parameters on DNA delivery efficiency of the PIG system was investigated by scoring transient GUS expression. The highest number of blue spots was observed at 16 mM of spemidine and 1.5 M of calcium chloride, respectively. And the amount of gold particles required for the best GUD expression was 2 mg. Optimum GUS transient expression was observed at target distance of 12 cm and helium pressure of 3.5 bar (50 psi). Gene introduction efficiency of the PIG system was observed almost similar to that of the Biolistic Gun (Bio-Rad Company). Since PIG system is simple to operate and one doesn't need disposable accessaries, the PIG system can be easily applied to various replication experiments.

• Journal of the Korean Society of Radiology
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• v.12 no.2
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• pp.193-199
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• 2018

In this research, 15 patients were diagnosed with 1.5T and 3.0T MRI instruments (Philips, Medical System, Achieva) to minize Ferromagnetic artifact and find the optimized Tesla. Based on the theory that the 3.0T, when compared to 1.5T, show relatively high signal-to-ratio(SNR), Scan time can be shortened or adjust the image resolution. However, when using the 3.0T MRI instruments, various artifact due to the magnetic field difference can degrade the diagnostic information. For the analysis condition, area of interest is set at the background of the T1, T2 sagittal image followed by evaluation of L3, L4, L5 SNR, length of 3 parts with Ferromagnetic artifact, and Histogram. The validity evaluation was performed by using the independent t test. As a result, for the SNR evaluation, mere difference in value was observed for L3 between 1.5T and 3.0T, while big differences were observed for both L4, and L5(p<0.05). Shorter length was observed for the 1.5T when observing 3 parts with Ferromagnetic artifact, thus we can conclude that 3.0T can provide more information on about peripheral tissue diagnostic information(p<0.05). Finally, 1.5T showed higher counts values for the Histogram evaluation(p<0.05). As a result, when we have compared the 1.5T and 3.0T with SNR, length of Ferromagnetic artifact, Histogram, we believe that using a Low Tesla for Spine MRI test can achieve the optimal image information for patients with disk operation like PLIF, etc. in the past.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.2
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• pp.105-116
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• 2004

According to the developing advanced techniques and removal of Selective Availability, much research has been conducted to improve the accuracy of GPS positioning in absolute and relative mode by estimating the nuisance parameters such as atmospheric effect, clock errors and multipath. Especially, the continuous effort of establishing the CORS in many countries and the effort of ICS making effective global networking make more application areas and the necessity of more precise location is being increased. Some of the countries like German, Japan and Swiss already utilized the Virtual Reference System for better location accuracy and services. In this study, the VRS system is investigated in terms of system principle, required H/W and S/W, management and operation, revision of related law, expected application and market etc. and find optimal solution in each aspect for economic and fast set up of the system in this country. The analysis of Korean CORS, communication infra and market estimation is performed for the efficient system establishment. Also. the suggestion on the advertisement and education of the system is also included. It is expected that this study contributes for the establishment of effective and precise nationwide location service so that many SOC areas including navigation, GIS, Telematics, LBS can provides better service for the users.