• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2442-2451
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• 2000

Recently, there have been some trials to use a TV system as an Internet terminal for easier and more convenient use of Internet. Because a TV Web browser system has a TV display with a set-top box as an execution environment, it has some limits and there are specific requirements. The efficient implementation of the Web browser for TV needs the proxy server that includes HTML conversions for TV environments as well as general cash functions. In order to implement a Web environment on general TV and set-tops, we introduce a distributed structure using a proxy server and propose TV - HTML conversions as an important feature of the proxy server.

• Journal of the Korean housing association
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• v.21 no.1
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• pp.123-130
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• 2010

The purpose of this study is to find the characteristics of space utilization and the problems that follows after converting in a new developmental residential area. This study used the content-analysis method and analysis was made on the floor plans for 95 different conversion cases. Above all, 190 unit plans (the unit plans for conversion before and after) were analyzed. The results of this study were as follows; 1) There were 8 types of conversion according to such usages as residential, commercial and residential-commercial buildings. 2) In the case of conversions, from residential to commercial, there was a tendency each floor was integrated to exclusive use for commercial or commercial with small portions of residential usage. And in the case of conversions from commercial to residential, there was a tendency that all space of each floor were changed to exclusive usages for residential purposes. 3) In case of usage conversion from commercial to residential, there were constraints for balcony installation, because of its original lot-structure and building equipments. Also, when the basement was converted for residential purpose, there was no possibility for an extra lighting or ways to ventilate the area.

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.1-9
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• 2013

The transformation of alkylaromatic hydrocarbons using zeolite catalysts play big part in the current petrochemical industry. Here we review recent advances in the understanding of the reaction mechanisms of various alkylaromatic conversions with respect to the structural and physicochemical properties of zeolite catalysts employed. Indeed, the shape-selective nature of zeolite catalysts determines the type of reaction intermediates and hence the prevailing reaction mechanism together with the product distribution. The prospect of zeolite catalysis in the developement of more efficient petrochemical processes is also described.

• Journal of Digital Convergence
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• v.14 no.2
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• pp.175-181
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• 2016

Cloud storage servers do not detect duplication of conventionally encrypted data. To solve this problem, convergent encryption has been proposed. Recently, various client-side deduplication technology has been proposed. However, this propositions still cannot solve the security problem. In this paper, we suggest a secure source-based deduplication technology, which encrypt data to ensure the confidentiality of sensitive data and apply proofs of ownership protocol to control access to the data, from curious cloud server and malicious user.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.2
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• pp.76-84
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• 2002

On-line conversion estimation of enzymatic esterification reactions in solvent-free media was investigated. In principle, conversion to ester can be determined from the amount of water produced by the reaction, because water is formed as a by-product in a stoichiometric manner. In this study, we estimated the water production rate only from some measurements of relative humidity and water balances without using any analytical methods. In order to test the performance of the on-line conversion estimation, the lipase-catalyzed esterification of n-capric acid and n-decal alcohol in solvent-free media was performed whilst controlling water activity at various values. The reaction conversions estimated on-line were similar to those determined by offline gas chromatographic analysis. However, when the water activity was controlled at higher values, discrepancies between the estimated conversion values and the measured values became significant. The deviation was found to be due to the inaccurate measurement of the water content in the reaction medium during the initial stages of the reaction. Using a digital filter, we were able to improve the accuracy of the on-line conversion estimation method considerably. Despite the simplicity of this method, the on-line estimated conversions were in good agreement with the off-line measured values.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.186-188
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• 2016

본 논문에서는 모바일 환경에서 동적서명인식에 관해 원본서명과 숙련된 위조서명의 구분을 검증하는 방법을 제안한다. 속도/거리 정보 실험(Data1)과 속도/거리정보와 가속도계를 추가 실험(Data2)을 원본 서명과 위조서명에 대한 테이블을 만들고, 비교하여 원본 서명의 인식률 확인한다. 제시한 방법은 각각 모바일 환경에서 10명이 20 번삑 손가락으로 테스트 하였다. 원본서명에서 딥 러닝중의 하나인 MLP를 실험한 결과 원본 서명에서 Data1은 92%, Data2는 95%의 정확도를 보였으며, 위조서명에서 Data1은 82%, Data2는 85%를 보였다. 그리고 AE에서 실험한 결과 Data1은 원본 서명에서 Data1은 95%, Data2는 97%의 정확도를 보였으며, 위조서명에서 Data1은 91.5%, Data2는 93%의 정확도가 보였다. 실험결과 위조서명에 대해서는 MLP로 위조서명을 분류하는 것보다 OAE에서 분류하는 것이 더 좋은 정확도를 보여준다.

• KSBB Journal
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• v.23 no.6
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• pp.509-512
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• 2008

The hydrolysis reaction of soybean oil was conducted experimentally by various source enzymes. The analytical result of hydrolysate of soybean oil showed that the compositions were linoleic acid, olic acid, palmitic acid, and stearic acid in order. The enzymes CR-E and CC-E from Candida rufosa and Candida cylindracea had two hold or more hydrolysis conversions than those of Lipase 16, Novozyme 871, and Lipolase-100L under the same conditions. Therefore CR-E and CC-E were selected for further experiments. These two enzymes had similar ranges of optimun conditions as follows: pH 3-6, $35-45^{\circ}C$, and water to soybean oil ratio of 3.3 or above. They finally got conversions 95% above.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6C
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• pp.594-600
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• 2002

A data manipulation unit capable of bit partitioned shift and various multimedia data type conversions in addition to conventional shift, is presented. Utilizing the similarity between the data type conversion and the shift, the addition of small amount of interconnections to conventional barrel shifter enables data type conversion as well as shift operations with minimal hardware overhead. The presented data manipulation unit is composed of the shifter block for conventional shift and a pack and a unpack block. It has been designed with verilog HDL and the VLSI implementation results using compass 0.6 um standard cell are discussed.

• Journal of the Korean Applied Science and Technology
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• v.13 no.1
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• pp.67-74
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• 1996

This study was conducted to find a catalyst system which has high conversion and selectivity for the oxidative coupling of methane to produce ethane and ethylene. Various catalysts were tested in a fixed bed reactor ar $750^{\circ}C$, 1 atm, and the feed ratio($CH_4/O_2$) of 2/1. Under the reaction condition, 10wt%$PbSO_4/MgO$ catalyst showed the highest catalytic activity : methane conversion, $C_2$ selectivity and yield were 50, 40 and 20%, respectively. Catalysts containing sulfate compounds, 10wt%$PbSO_4/MgO$, 10wt%$MgSO_4/MgO$ and $Na_2SO_4/MgO$ revealed a moderate methane conversions such as 38, 50 and 50%, respectively and low $C_2$ selectivities such as 18, 5 and 9%, respectively. Catalysts containing carbonate compounds, 10wt%$PbCO_3/MgO$, 10wt%$Li_2CO_3/MgO$ and $NaCO_3/MgO$, also showed a moderate methane conversions such as 64, 44 and 51%, respectively and low $C_2$ selectivities such as 5, 6 and 2%, respectively. With the existence of chlorine and mercury, $C_2$ selectivity was decreased.

• New & Renewable Energy
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• v.19 no.4
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• pp.11-19
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• 2023

Levulinic acid (LA) derived from cellulosic biomass, serves a crucial intermediate that can be used in various chemical conversions. This study focused on optimizing the production of LA using two types of pretreated rice husk (de-ashed and delignificated cellulosic biomass) in a batch reaction system through catalytic conversion with sulfuric acid. To determine the optimal conditions, the conversions of glucose and α-cellulose were examined to compare the effects of pretreatment on the rice husk. The experimental parameters covered a broad spectrum, including temperatures ranging from 140℃ to 200℃, a reaction time was up to 600 minutes, and a substrate to catalyst (acid solution) ratio of 100 g/L. The highest LA yield was 44.8%, achieved from de-ashed rice husk with 3.0 wt.% of sulfuric acid at 180℃ and with a reaction time of 180 minutes. In the case of the delignificated rice husk, a LA yield of 43.6% was obtained with 3.0 wt.% of sulfuric acid at 200℃ and with reaction time of 30 minutes.