• Applied Chemistry for Engineering
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• v.7 no.4
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• pp.698-706
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• 1996

Dehydrogenation of methanol to produce formaldehyde was carried out over various silica-alumina catalysts doped with alkali metals in a continuous flow system. The reaction was rather dependent on Lewis acid than Br${\ddot{o}}$nsted acid suggesting that dehydrogenation of methanol was an electronic reaction. The Br${\ddot{o}}$nsted acid sites on silica-alumina were neutralized by doping with alkali metals, and the neutralization effect of Br${\ddot{o}}$nsted acid was dependent on the electron-donating capacity of the dopant metals. Activation energy for dehydrogenation of methanol decreased when Br${\ddot{o}}$nsted acid was neutralized by doping with K.

• Annual Conference of KIPS
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• 2006.11a
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• pp.511-514
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• 2006

장기간동안 여러 기관의 협력을 통해 이루어지는 전사적 아키텍처(Enterprise Architecture, EA)의 특성상, 기관에서 EA를 도입부터 운영 및 정착, 그리고 고도화시키기 위해서는, 조직의 EA업무 수행 능력을 평가하고 개선하기 위한 적합한 EA기준이 필요하다. 하지만 국내 EA에 대한 연구는 아직 도입단계이기 때문에, EA조직의 수준측정을 위한 EA성숙도모델에 대한 연구는 활발하지 않다. 이러한 상황에 따라, EA조직의 수준측정을 위한 EA성숙도모델에 대한 연구는 활발하지 않다. 이러한 상황에 따라, EA성숙도 모델을 정의하고, 측정을 위한 평가항목과 해당 지침을 제시하고자 한다. EA성숙도 모델은 CMMI의 연속형 모델을 참고하여, EA성숙도 모델의 선진사례 분석과 정부 '정보시스템의 효율적 도입 및 운영 등에 관한 법률'을 기반으로 하여 총 4개영역 15개평가요소를 정의하였다. 성숙도 단계는 인식부터 최적화 단계까지 총 5단계로 정의하였으며, 이 중에서 첫 번째 단계인 인식단계의 평가항복별 지침을 제시하였다. 이렇게 각 항목에 대한 측정 대상자들의 이해를 높임으로써 좀 더 정확한 성숙도 평가 결과와 이를 기반으로 EA고도화를 위한 좋은 기준을 제시하고자 정의하였다.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1777-1787
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• 2000

The purpose of this study was to select an effective and economical alkali source for sulfur-utilizing autotrophic denitrification. Tests on acid neutralization and denitrification at various alkali/sulfur mixing ratios were performed for charcoal, briquette ashes, sea shell, and limestone. The results of the experiments showed that sea shell was the most effective alkali source because it could provide more surface area than limestone, and the optimal alkali/sulfur mixing ratio was 1/1(V/V). In a sulfur/sea shell packed bed reactor, the denitrification efficiency was above 90% up to a loading rate of 116 g $NO_3{^-}-N/m^3-day$. but the denitrification efficiency deteriorated to 48% at the loading rate of 145 g $NO_3{^-}-N/m^3-day$. The average $SO_4{^{2-}}$ generation per g of $NO_3{^-}-N$ removed was 7.02 g, which is lower than the theoretical value of 7.54 g. Denitrification and sulfate generation appeared to be a first-order and a zero-order reaction with a reaction rate constant of 0.146 /hr and -53.1 mg/L-hr, respectively. According to nitrogen mass balance, 71~109%, with an average of 90%, of the removed nitrogen was recovered as $N_2$ gas.

• Journal of Preventive Medicine and Public Health
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• v.25 no.2 s.38
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• pp.141-147
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• 1992

This study was carried out not only to determine blood alcohol levels by time but also to examine the changes of working ability and reaction speed after ingestion of alcohol. Fifteen healthy students aged from 21 to 27 volunteered as subjects for this study, Liguor (Sojoo) in concentration of 25% ethyl alcohol was administrated with the amount of 1ml of ethyl alcohol per kg of body weight to the subjects. The concentration of alcohol in the blood were determined by the 'Alcohol Sensor 100' at 5, 30, 60 and 90 minutes after the administration of alcohol. Also, the choice reactiontest, the eye-hand coordination test and kraepelin test were examined at the same time after checking of alcohol concentration in the blood. The results of this study can be summarized as follows. 1. Mean blood alcohol level changes resulting from administration of 1ml of ethyl alcohol per kg of body weight were $0.16%(160{\pm}57mg/100ml,\;0.10%(100{\pm}42mg/100ml),\;0.08%(80{\pm}36mg/100ml)\;and\;0.03%(30{\pm}24mg/100ml)$ at the 3, 30, 60 and 90 minutes after the administration respectively The peak in the concentration of blood alcohol was 5 miniutes after the ingestion according to alcohol examination by the respiration. 2. As for choice reaction test, reaction times became prolonged as blood alcohol levels increased. The reaction time showed a significant changes when the blood alcohol concentration reached 0.08% or more after alcohol ingestion. 3. In eye and hand coordination test, the accuracy of the performance became decreased as blood alcohol levels increased. The difference of accuracy of the test was significantly shown when alcohol levels in the blood reached 0.08% or more after alcohol intake. 4. As for kraepelin test, the abilities of calculation also became lowered as blood alcohol levels increased. The abilities of calculation differed signigicantly from control group when alchool levels of 0.08% and more.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.300-306
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• 2012

In this paper, we propose a vision based hand motion recognition method for an untouchable user interface of smart devices. First, an original color image is converted into a gray scaled image and its spacial resolution is reduced, taking the small memory and low computational power of smart devices into consideration. For robust recognition of hand motions through separation of horizontal and vertical motions, the horizontal principal area (HPA) and the vertical principal area (VPA) are defined respectively. From the difference images of the consecutively obtained images, the center of gravity (CoG) of the significantly changed pixels caused by hand motions is obtained, and the direction of hand motion is detected by defining the least mean squared line for the CoG in time. For verifying the feasibility of the proposed method, the experiments are carried out with a vision system.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.6
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• pp.59-68
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• 2002

In this paper, we design the two-dimensional Discrete Wavelet Transform (2D DWT) filter that is widely used in various applications such as image compression because it has no blocking effects and relatively high compression rate. The filter that we used here is two-channel four-taps QMF(Quadrature Mirror Filter) Lattice filter with PR (Perfect Reconstruction) property. The proposed DWT architecture, with two consecutive inputs shows an efficient performance with a minimum of such hardware resources as multipliers, adders, and registers due to a simple scheduling. The proposed architecture was verified by the RTL simulation, and utilizes the hardware 100%. Our architecture shows a relatively high performance with a minimum hardware when compared with other approaches. An efficient memory mapping and address generation techniques are introduced and the fixed-point arithmetic analysis for minimizing the PSNR degradation due to quantization is discussed.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.342-342
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• 2011

댐의 건설로 인해 자연적인 물의 흐름이 댐 운영에 의하여 조절되기 때문에 유사의 연속성 및 유량의 변화에 따른 지형 환경적 변화가 예상된다. 따라서 영향분석을 위한 체계적인 조사 및 연구가 필요할 것이다. 본 연구는 내성천 영주댐 건설 예정지로부터 48.4km 하류인 회룡포 구간에서 하상변동이 예상됨에 따라 현장 조사를 수행하고, 장래변화를 예측하기 위하여 수치모델을 수행하였다. 수리학적 변화량은 금회 수립중인 하천정비계획의 계획 홍수량인 댐건설 전 4,040cms, 댐건설 후 2,934cms로 구분하고, 유사변화량은 영주댐 실시설계 보고서결과를 적용하여 분석하였다. 한편 2001년과 2010년의 실측종단변화를 검토한 결과, 회룡포 구간에서 0.5m~1.7m의 퇴적이 진행되고 있음을 알 수 있었다. 수치모델 및 실측한 데이터를 종합적으로 판단한 결과, 단기호우사상에 대해 댐 건설 후 회룡포 구간의 사주퇴적능력은 -0.05m로 감소되어 그 영향은 비교적 미미할 것으로 분석 되었고, 대부분의 변화는 주수로에서 -0.5~0.5m로 변화될 것으로 예측되었다. 하상 변동의 양상은 실측한 10년간의 종단변화와 같은 경향성을 보이며, 횡단번호 No.15 이후로 0.5m이상 퇴적이 이루어 질 것으로 예측되었다. 본 연구결과는 댐건설로 인한 하천 하상변화에 대한 특성을 파악하고 하천공사 나 수리구조물 설계의 기초자료로 활용될 수 있을 것으로 판단되며, 향후 지속적인 모니터링 및 조사를 통하여 하상변동양상을 관측하고 분석할 필요가 있을 것으로 판단된다.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.2
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• pp.115-122
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• 2007

In this paper, a novel fault detection method for fault tolerant control is proposed when the NPC inverter has a open failure in the switching device. The open fault of switching device is detected by checking the variation of a leg-voltage in the neutral-point-clamped inverter and the two phases control method is used for continuously balance the three phases voltage to the load. It can be achieve the fault tolerant control for improving the reliability of the NPC inverter by the fault detection and reconfiguration. This method has fast detection ability and a simple realization for fault detection, compared with a conventional method. Also, this fast detection ability improved the harmful effects such as DC-link voltage unbalance and overstress to other switching devices from a delay of fault detection. The proposed method has been verified by simulation and experiment.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.291-298
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• 2022

Unexpected massive disasters have occurred around the world, causing enormous socio-economic damage. The military has long been enacting laws, organizing organizations and establishing systems for crisis and disaster management, but it did not consider the situation when military essential functions were suspended due to unpredictable and massive disasters. With the September 11 terrorist attacks, the U.S. military has developed COOP strategy aimed at continuing military essential functions in all crisis, and is contributed to national continuity by ensuring uninterrupted national security functions. Korean military has established a crisis and disaster management system, but focuses on managing and controlling disasters and crisis situations. Korean military needs a system to guarantee military essential functions even in national crisis beyond its management capabilities. In this study, We compared and reviewed the U.S. administration and military COOP guidelines and directives, ISO22301 international standards., and developed planning guidelines suitable for the Korean military situation by responding to detailed items based on ISO22301. In particular, the U.S. military(DoD, Army, Navy, Air Force) COOP guidelines were drawn and incorporated into the guidelines(such as protection and succession of command authority, the fulfillment of essential functions and operational security, etc.). The planning guidelines are expected to be used as reference materials for the introduction of COOP systems in the military and the establishment of plans in the future.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.1
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• pp.37-43
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• 2013

Purpose: The present study was conducted to investigate whether the directions of eye movement in playing computer games for certain period affected the change of near point of convergence (NPC) and fusional reserve (FR) or not. Methods: Total 40 subjects in 20s who have the visual acuity of 1.0 or higher without any ocular disease and accommodative dysfunction were asked to successively play computer games. After the subjects were moving eyes in horizontal and vertical directions for 40 and 90 minutes, their horizontal fusional reserves, vertical fusional vergence and near point of convergence were measured. Results: The near point of convergence showed a tendency to be receded after computer gaming in the horizontal and vertical directions, and both of horizontal and vertical fusional reserves were significantly reduced. The range of declined fusional reserves and receded near point of convergence after computer gaming for 90 minutes was smaller than those after computer gaming for 40 minutes. The change of binocular vision was affected by the horizontal eye movement rather than the vertical movement when analyzed by the direction of eye movement. Conclusions: This study revealed that the change in FR and NPC was different along with dominant direction of eye movement during visual display terminal (VDT) tasks. Therefore, the adjustment of VDT working time is required to prevent the dysfunction of binocular vision according to the dominant direction of eye movement during VDT task.