• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.7A
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• pp.587-596
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• 2005

In this paper, we propose an OFDMA/CDM-based cellular system, which accommodates multiple users in frequency-domain and multiplexes user data with frequency-domain spreading. The proposed system utilizes random codes to discriminate cells and adopts the pre-equalization to enhance the performance. For cellular applications, a number of pre-equalization techniques are compared and an efficient power allocation scheme is suggested with a transmit power constraint. Especially, the validity of OFDMA/CDM based cellular system is investigated, by comparing the performance for varying the number of multiplexed data symbols at different locations. Finally the pre/post-equalization is proposed to reduce the performance degradation caused by time delay.

• Journal of Chest Surgery
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• v.27 no.5
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• pp.364-373
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• 1994

Alpha 1-Proteinase inhibitor[PI] was known as a major protective enzyme against to excessive hydrolytic and proteolytic reaction. So, it was suggested that Alpha 1-PI may implicated in growth of bronchogenic cancer. This study was undertaken to investigate the role of Alpha 1-PI in local invasion of bronchogenic cancer. Three groups of patients were studied; Preliminary research group of 15 bronchogenic cancer patients, Main research group of 13 bronchogenic cancer patients and Normal control group of 10 nephrectomy donor. Serum Alpha 1-PI level was observed in each group of patients during pre-and postoperative days. Pre-operative serum Alpha 1-PI level in preliminary research group [329.2$\pm$14.21mg/dl]and main research group[406.2$\pm$39.30mg/dl] were higher than in normal control group[236.2$\pm$19.55mg/dl] significantly[p<0.005]. Serial Alpha 1-PI level in each group during pre-and postoperative days shows peaked at 3rd. postoperative day in preliminary and main research group, thereafter decreased gradually. Immunohistochemical study for Alpha 1-antitrypsin[A1AT] was carried out by ABC[avidin-biotin peroxidase complex] method using Alpha-1 antitrypsin DAKOR to tumor tissues of 13 lung cancer patients in main research group. 6 cases[46.2%, squamous cell ca.;5, adenocarcinoma;1] of above 13 cases show positive immunoreactivity for A1AT. In conclusion, alpha 1-PI and elastase are disclosed that have defined actions for lung cancer growing or spreading.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.2
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• pp.85-90
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• 2017

Various mobile devices are spreading in recent developments in mobile computing environments. Especially the popularity of mobile devices equipped with GPS has become widespread, and various application services utilizing location information are born. In this paper, we propose a system model for storing and managing the trajectory of moving objects, which is the set of location information of moving objects acquired in continuous time, and the UDF (User-Defined Functions) based trajectory index method which can quickly query the large data set of moving object and the Pre-Materialized table method. Then we compare and evaluate the performance of each method through experiments. Experimental results show that the Pre-Materialized table method is about 1.2 times faster than the UDF based trajectory index method on execution time.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.439-444
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• 2012

Photovoltaic energy is regarded as the key solution to the instability of energy supply and environmental pollution, and it is spreading from the developed countries to world wide. This paper looks into guide lines of KESCO (Korea electrical Safety Corporation) on Photovoltaic system and analyzed case of inconsistencies of pre-service inspection. Through these analyses it will be possible to prevent possible accidents in the process of installing Photovoltaic system and thus ensure electrical safety of Photovoltaic system.

• Journal of the Korean GEO-environmental Society
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• v.13 no.2
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• pp.5-17
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• 2012

The amount of snow due to global warming and climate change has recently increased. The effective management of snow removal materials will be required. First, on the basis of domestic winter temperature, it is not necessary to get a baseline to less than the freezing point of $-52^{\circ}C$ for the calcium chloride($CaCl_2$) of 30%.. In terms of cost comparison between calcium chloride($CaCl_2$) and sodium chloride($NaCl$), the calcium chloride($CaCl_2$) is 2 to 3 times more expensive, and the supply of the calcium chloride($CaCl_2$) is not produced in domestic country and is in the conditions that have to imports all needed. Accordingly, the effective use scheme of snow removal materials should be considered to multifaceted ways. Thus, the objective of this study is to develop effective method and to replace from calcium choride($CaCl_2$) to sodium chloride($NaCl$) solution in the current snow removal operating system that uses a pre-wetted salt spreading method. The effective method that equals to the quality of the existing snow removal materials was developed in this study through performance tests for deicing chemicals, corrosion test of steel and freezing and thawing tests of concrete.

• International Journal of Computer Science & Network Security
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• v.21 no.1
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• pp.27-33
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• 2021

The whole world now is dealing with Coronavirus, and it has turned to be one of the most widespread and long-lived pandemics of our times. Reports reveal that the infectious disease has taken toll of the almost 80% of the world's population. Amidst a lot of research going on with regards to the prediction on growth and transmission through Symptomatic carriers of the virus, it can't be ignored that pre-symptomatic and asymptomatic carriers also play a crucial role in spreading the reach of the virus. Classification Algorithm has been widely used to classify different types of COVID-19 carriers ranging from simple feature-based classification to Convolutional Neural Networks (CNNs). This research paper aims to present a novel technique using a Random Forest Machine learning algorithm with hyper-parameter tuning to classify different types COVID-19-carriers such that these carriers can be accurately characterized and hence dealt timely to contain the spread of the virus. The main idea for selecting Random Forest is that it works on the powerful concept of "the wisdom of crowd" which produces ensemble prediction. The results are quite convincing and the model records an accuracy score of 99.72 %. The results have been compared with the same dataset being subjected to K-Nearest Neighbour, logistic regression, support vector machine (SVM), and Decision Tree algorithms where the accuracy score has been recorded as 78.58%, 70.11%, 70.385,99% respectively, thus establishing the concreteness and suitability of our approach.

• BMB Reports
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• v.55 no.12
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• pp.615-620
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• 2022

The murine leukemia virus-based semi-retroviral replicating vectors (MuLV-based sRRV) had been developed to improve safety and transgene capacity for cancer gene therapy. However, despite the apparent advantages of the sRRV, improvements in the in vivo transduction efficiency are still required to deliver therapeutic genes efficiently for clinical use. In this study, we established a gibbon ape leukemia virus (GaLV) envelope-pseudotyped semi-replication-competent retrovirus vector system (spRRV) which is composed of two transcomplementing replication-defective retroviral vectors termed MuLV-Gag-Pol and GaLV-Env. We found that the spRRV shows considerable improvement in efficiencies of gene transfer and spreading in both human glioblastoma cells and pre-established human glioblastoma mouse model compared with an sRRV system. When treated with ganciclovir after intratumoral injection of each vector system into pre-established U-87 MG glioblastomas, the group of mice injected with spRRV expressing the herpes simplex virus type 1-thymidine kinase (HSV1-tk) gene showed a survival rate of 100% for more than 150 days, but all control groups of mice (HSV1-tk/PBS-treated and GFP/GCV-treated groups) died within 45 days after tumor injection. In conclusion, these findings sug-gest that intratumoral delivery of the HSV1-tk gene by the spRRV system is worthy of development in clinical trials for the treatment of malignant solid tumors.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.7
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• pp.446-449
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• 2015

An improvement of light-extraction efficiency of organic light-emitting diodes was studied by using random-textured films (RTF). Device was made in a structure of RTF/glass/ITO/TPD/$Alq_3$/LiF/Al. RTF mold was made by spreading PDMS solution on a sandpaper. By pressing this mold on the glass substrate pre-coated with ZPU material, the RTF was obtained. From this study, there was an improvement of external quantum efficiency by about 30% in the device with the random-textured film (RTF 40) compared to that of the reference one.

• The Korean Journal of Community Living Science
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• v.15 no.3
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• pp.29-43
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• 2004

The purpose of this study was to calculate the economic effect of Women-Farmer's Center. Since 2001, The Ministry of Agriculture and Forestry has run Women-Farmer's Centers in which women-farmers can receive the care for their pre-schooling children, after-school learning service, and city-farm exchange, education, and counseling. In other words, Women Farmer's Center provides not only improvement of ease and quality of life of women-farmer's, but also spreading economic effect to community and country. By calculation based on business plan of 14 centers that run centers, total economic income effects are 2,784 million won, which consist of 1,265 million won for counseling, 146 million won for the care of infants and children, 139 million won after-school learning, 1,020 million won for education, and 214 million won for city-farm exchange program. The Women-Farmer's Center should be managed reasonably with government support so that Women-Farmer's Center will become as a base camp for young women farmers to participate in agriculture and rural community and increase its economic effect for the nation in the future.

• IE interfaces
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• v.17 no.1
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• pp.93-103
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• 2004

Service importance has been growing increasingly as competition element of enterprises according to going on rapid softness, information and knowledge of industrial infrastructure recently. Quality management system that implemented in manufacturing sector have been spreading rapidly to service company, but the company performing pure engineering service only in construction fields performed mainly the evaluation on the operational aspect such as degree of implementation of the established system because it is difficult to objective evaluation on the activity of the established quality management system or quality assurance system. This study would like to make on offer the improvement points based on the evaluation of service quality and the itself evaluation result through the questionnaire on the service offerers and customers using the pre-qualified SERVQUAL model in establishment of the improvement goal of the company. According to the result of this study, it is analyzed a gap and required to establish a counter-plan to correct many gaps discovered between the real offered level and the expect level of custom.