• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.7
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• pp.1-5
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• 2012

At the present time when the limits of the magnetic storage systems appear, the holographic data storage (HDS) devices with high data transfer rate and high recording density are emerging as attractive candidates for next-generation optical storage devices. In this paper, to effectively improve the detection performance that is degraded by the two-dimensional inter-symbol interference under the HDS channel environment and the pixel misalignment, an iterative two-dimensional equalization scheme is proposed based on the contraction mapping theorem. In order to evaluate the performance of the proposed scheme, for various holographic channel environments we measure the BER performance using computer simulation and compare the proposed one with the conventional threshold detection scheme, which verifies the superiority of the proposed scheme.

• Computational Structural Engineering
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• v.4 no.1
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• pp.95-108
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• 1991

An explicit finite element method can be executed more rapidly and effectively on vector computer than on the scalar computer because it has suitable structures for vector processing. In this paper, an efficient vectorization method of the explicit finite element program on the memory-to-memory type vector computer is proposed. First, the general vectorization method which can be applied regardless of the vector architecture is investigated, then the method which is suitable for the memory-to-memory type vector computer is proposed. To illustrate the usefulness of the proposed vectorization method, DYNA3D, the existing explicit finite element program, is migrated on HDS AS/XL V50 which is the memory-to-memory type vector computer. Performance results on actual test show a vector/scalar speedup is above 2.4.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.5
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• pp.215-219
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• 2014

In holographic data storage (HDS), a high transmission rate is accomplished through the use of a charge coupled device array for reading two-dimensional (2D) pixel image data. Although HDS has many advantages in terms of storage capacity and data transmission rates, it also features problems, such as 2D intersymbol interference (ISI) by neighboring pixels and interpage interference (IPI) by multiple images stored in the same holographic volume. Modulation codes can be used to remove these problems. We introduce a 2D 8/9 error-correcting modulation code. The proposed modulation code exploits the trellis-coded modulation scheme, and the code rate is larger (about 0.889) than that of the conventional 6/8 balanced modulation code (an increase of approximately 13.9%). The performance of the bit error rate (BER) with the proposed scheme was improved compared with that of the 6/8 balanced modulation code and the simple 8/9 code without the trellis scheme.

• Journal of Environmental Health Sciences
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• v.48 no.6
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• pp.324-330
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• 2022

Background: Lung injuries due to exposure to humidifier disinfectants (HDs) were reported in 2011 in South Korea. As a result of the government's epidemiological investigation and toxicity test study, it was found that HDs caused health damage such as lung disease. Objectives: The purpose of this study was to classify HD exposure ratings and analyze the affecting factors that could identify the relationship with lung disease. Methods: Exposure assessment for HDs was conducted using a questionnaire during face-to-face interviews with the applicants. Ratings of high exposure (Class 1) and low exposure (Class 2) were cross-tabulated with clinical ratings (acceptable and unacceptable). Logistic regression analysis was carried out by setting the clinical rating of lung disease as a dependent variable and the socio-demographic and exposure characteristics obtained through the questionnaire as independent variables. Results: The concentration in air of polyhexamethylene guanidine (PHMG) was 71.96±107.47 ㎍/m³, and the exposure concentration was 15.21±23.28 ㎍/m³ . The exposure rating was overestimated with 97.1% of affected subjects having high exposure using margin of exposure (MOE), but only 9.9% matching the clinical class. In the overestimated group, it could be explained by the fact that the exposure time was long and the subjects had already recovered from damage symptoms. As a result of logistic regression analysis, ten variables were found to be significant influencing factors. Conclusions: A new exposure rating could be calculated based on the MOE, and factors affecting lung disease could be estimated through comparative evaluation with the clinical rating.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.246-248
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• 2001

본 연구에서는 섬유상담체가 설치된 고정화 생촉매 air-lift bioreactor를 개발하여 HDS(hydrodesulfuriza tion)를 거친 디젤유를 대상으로 고심도 탈황을 시도하였다. 생촉매의 활성유지와 세포성장에 필요한 탄소원으로는 glucose보다 sucrose가 더 유리한 것으로 나타났다. 반복회분탈황반응을 통하여 약 60 시간 만에 디젤 중 황함량이 550ppm 에서 50ppm 이하로 감소되었다.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.27-32
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• 1996

공학보 이론과 strain energy에 기초한 Castiliano의 제2정리를 이용하여 두께감소 holddown spring(HDS) 집합체의 탄성강성도를 해석적으로 구할 수 있는 방법을 제시하였고 아울러 보의 굽힘 모우멘트. 전단력, 축력등에의한 모든 strain energy를 고려하여 탄성강성도 식을 유도하였다. KOFA형 HDS과 동일한 칫수 설계 공간을 갖도록 고안된 너비감소 HDS에 대해서 유도한 식으로부터 탄성강성도를 계산하고 분석하였다. 너비감소 HDS의 탄성강성도는 KOFA HDS의 탄성강성도 보다 약32-33%이상 높았으며 전단력과 축력이 탄성강성도에 미치는 영향은 약 0.15-0.21%정도였다.

• Journal of Haehwa Medicine
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• v.12 no.2
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• pp.11-40
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• 2004

This study analyzed the contents of the research papers concerning the vascular dementia(VD) recorded in Chinese medical journal published over the period between 1998 and 2000. As a result, the following conclusion was drawn. The Chinese medical category of VD includes Sun-Mang(善忘), Chi-Mae, Jung-Pung-Chi-Mae and so on, and the Major mechanism of the VD is Bon-Heo- Pyo-Sil(state of deficient vital essence and excessive pestilential vapor;本虛標實), Bon(本) includes Sin-Jeong-Heo-Son(腎精虧損), Ki-Hyeol-Hyu-Heo(氣血虧虛) and Pyo(標) includes Dam-Chae-Eo-Jo(痰滯瘀阻), Ki-Chae-Hyeol-Eo(氣滯血瘀), Gan-Yang-Sang-Hang(肝陽上亢). It is mainly used DSM and evidence of brain-vascular disease in brain CT or MRI as the criterion for diagnosis in Western medicine and MMSE, HDS, ADL is used as assistant diagnostic indicator. "Principle of clinical study guidance for treatment of dementia by Chinese medicine, Western medicine"("中藥新藥治療痴呆 病的臨床硏究指導原則") is mainly used as the criterion for diagnosis in Chinese medicine. It is mainly used "Principle of clinical study guidance for treatment of senile disease by Chinese medicine, Western medicine"("中藥新藥治療老年病臨床硏究指導原則"), "Principle of clinical study guidance for treatment of dementia by Chinese medicine, Western medicine" as the criterion for treatment effect evaluation, and score change of MMSE and HDS is used as assistant evaluation indicator. The research papers reported that the use of prescriptions such as Hwan-Chong-Dan(還聰丹), Noi-Hyeol-So-Tong-Gu-Bok-Yaek(腦血疏通口服液), Yik-Gi-Gyo-Nang(益智膠囊), Cheon-Ma-Chok-Gi-Chung-Je(天麻促智沖劑), Sam-Gap-San-Ga-Mi-Bang(三甲散加味方), Seon-Ryong-Gyo-Nang(仙龍膠囊), Seong-Noi-Tang II(醒腦湯II號), Bo-Sin-Geon-Noi-Tang(補腎健腦湯), Ga-Mi-Tong-Gyu-Hyal-Hyeol-Tang(加味通竅活血湯), So-Jo-Yik-Ji-Bang(疏調益智方), Tong-Gyu-Hwal-Hyeol-Tang-Ga-Gam(通竅活血湯加減), Yik-Sin-Seong-Noi-Tang(益腎醒腦湯) led to the high efficacy.

• Applied Chemistry for Engineering
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• v.9 no.1
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• pp.101-106
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• 1998

Two types of CoMo/zeolite as well as $NiMo/{\gamma}-Al_2O_3$ were prepared and their activities and selectivities of low-temperature dibenzothiophene(DBT) hydrodesulfurization(HDS) were studied in high pressure fixed bed reactor. The HDS activities of CoMo/zeolites were higher than that of $NiMo/{\gamma}-Al_2O_3$ at temperatures below $225^{\circ}C$ while they were lower than that of $NiMo/{\gamma}-Al_2O_3$ at temperatures higher than $275^{\circ}C$. The main products from $NiMo/{\gamma}-Al_2O_3$ were biphenyl and cyclohexylbenzene. The product distribution of CoMo/zeolite catalysts was different from that of $NiMo/{\gamma}-Al_2O_3$. It is speculated that DBT is converted to alkylcyclohexane over zeolite based catalysts through both alkylation and hydrogenation reactions. The crystal structure of molybdenum was $MoO_3$ in fresh zeolite support while mixtures of $MoO_3$ and $MoS_2$ were observed in the aged catalyst.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.5
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• pp.51-57
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• 2014

In this paper, we introduce the adaptive threshold detection scheme based on an evolutionary arithmetic algorithm for the M-ary holographic data storage(HDS) system. The genetic algorithm is a particular class of evolutionary arithmetic based on the process of biological evolution, which is a very promising technique for optimization problem and estimation applications. In this study, to improve the detection performance that is degraded by the HDS channel environment and the pixel misalignment, the threshold value was assumed to be a population set of the evolutionary algorithm. The proposed method can find an appropriate population set of bit threshold, which minimizes bit error rate(BER) as increased generation. For performance evaluation, we consider severe misalignment effect in the 4-ary holographic data storage system. Furthermore, we measure the BER performance and compare the proposed methods with the conventional threshold detection scheme, which verifies the superiority of the proposed scheme.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.455-460
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• 2019

Hydrotreating catalysis refers to a various hydrogenation which saturate an unsaturated hydrocarbon, together with removing heteroatoms such as sulfur, nitrogen, oxygen, and trace metals from different petroleum streams in a refinery. Most refineries include at least three hydrotreating units for upgrading naphtha, middle distillates, gas oils, intermediate process streams, and/or residue. Among them, hydrotreating catalysis for residue are the core of the process, because of its complexity. This article reviews recent progress in tackling the issues found in the upgrading residues by hydrotreating, focusing on the chemistry of hydrodemetallization (HDM) and hydrodesulfurization (HDS). We also discuss the composition and functions of hydrotreating catalysts, and we highlight areas for further improvement.