• IEIE Transactions on Smart Processing and Computing
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• 제3권1호
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• pp.10-18
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• 2014

From the perspective of reducing the sampling cost of color images at high resolution, block-based compressive sensing (CS) has attracted considerable attention as a promising alternative to conventional Nyquist/Shannon sampling. On the other hand, for storing/transmitting applications, CS requires a very efficient way of representing the measurement data in terms of data volume. This paper addresses this problem by developing a measurement-coding method with the proposed customized Huffman coding. In addition, by noting the difference in visual importance between the luma and chroma channels, this paper proposes measurement coding in YCbCr space rather than in conventional RGB color space for better rate allocation. Furthermore, as the proper use of the image property in pursuing smoothness improves the CS recovery, this paper proposes the integration of a low pass filter to the CS recovery of color images, which is the block-based ${\ell}_{20}$-norm minimization. The proposed coding scheme shows considerable gain compared to conventional measurement coding.

• 성인간호학회지
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• 제20권1호
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• pp.135-148
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• 2008

Purpose: This study compared the effects of forced air warming and radiant heating on body temperature and shivering of patients with postoperative hypothermia. Methods: The quasi-experimental study was conducted with two experimental groups who had surgery under general anesthesia; 20 patients of group 1 experimented with the Bair Hugger as a forced air warming and 20 patients of group 2 experimented with the Radiant heater. The study was performed from July 3 to August 31, 2006 in a recovery room of an university hospital in a city. The effects of the experiment were measured by postoperative body temperature and chilling score at arrival and after every 10 minutes. The data were analyzed by t-test or ${\chi}^2$-test, repeated measures ANCOVA using SPSS/WIN 12.0. Results: The mean body temperature showed differences between the Bair Hugger group and Radiant Heater group at 40 minutes(F=-2.579, p=.034), 50minutes(F=-2.752, p=.027), and 60 minutes(F=-2.470, p=.047) after arrival to the recovery room. So, hypothesis 1 was partially accepted. The mean score of shivering showed differences between the Bair Hugger group and the Radiant Heater group, but it had no significant meaning. Hypothesis 2 was not accepted. Conclusion: We need more study to explore the effects and side effects of heating modalities to select a more effective heat treatment. The efficiency of heat modalities with regards to cost benefit, time consumption, and patients' discomfort such as burns should be considered.

• 정보처리학회논문지A
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• 제13A권5호
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• pp.421-428
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• 2006

본 논문에서는 복잡해져 가는 제어 컴퓨터의 높은 신뢰성 확보를 위해 시간 여분(time redundancy)의 일종인 재실행과 rollback 기법을 TMR 구조에 적절하게 혼용하는 방법을 제안한다 재실행과 rollback 기법은 약간의 추가 시간만으로 재구성(reconfiguration) 없이도 일시적인 결함(fault)에 의해 발생한 TMR 고장(failure)의 회복을 위해 상호 보완적으로 사용될 수 있다. 이를 위해 고장 검출시 가능한 모든 시스템의 고장상태 확률을 추정하였으며, 이를 바탕으로 전체 작업의 평균 실행시간이 최소가 되는 최적의 재실행과 rollback 횟수를 유도하였다. 또한 제안된 방법과 다른 고장회복 기법을 적용했을 때의 평균 실행 시간을 정량적으로 비교하여 그 우수성을 검증하였다.

• 멤브레인
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• 제22권6호
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• pp.381-394
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• 2012

최근 들어 혼합된 수용액으로부터 이온성을 가지는 부류의 물질들을 분리하기 위한 갖가지 화학적 물리적 방법들이 이용되어 왔다. 그중 분리막 접촉기를 이용한 막 투과추출공정은 오폐수와 같은 오염물 안의 중금속, 탄화수소계열 물질들을 투과추출 공정에 의해 회수할 수 있기 때문에 의약, 석유화학, 화공분야에서 분리시스템 그리고 회수를 위한 대안으로서 각광받아 왔다. 또한 투과추출공정은 쉬운 구동, 낮은 에너지 소모, 낮은 운영비, 높은 선택도와 같은 장점을 가지고 있다. 따라서 본고에서는 투과추출공정용으로의 응용을 위하여 그동안 개발된 분리막의 몇 가지 예와 그들의 성능에 대하여 조사하였다.

• 대한안전경영과학회지
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• 제13권4호
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• pp.213-223
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• 2011

Recent cross-country competition and Chinese steel industry because of the emerging steel industry in Korea is a very difficult situation. Therefore, the steel industry in order to overcome this difficult market environment, the quality, cost competitiveness, enhance customer service levels and enhance international competitiveness through is needed. In this study, the purpose of strengthening the competitiveness of steel companies in order and hit the recovery of raw materials have been developed to optimize the model, developed before and after the results were analyzed. In addition, when applied to other products in order to minimize risk and optimize cutting trial stage of development details of the model is presented in detail. Therefore, the developed model was applied to order the recovery of raw materials hits and significantly improved production planning time has been shortened dramatically. In the present study the contents of other products when properly applied and the competitiveness of companies to improve customer service levels are expected to be helpful.

• Journal of Communications and Networks
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• 제15권4호
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• pp.422-429
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• 2013

Advances in wireless sensor network (WSN) technology have enabled small and low-cost sensors with the capability of sensing various types of physical and environmental conditions, data processing, and wireless communication. In the WSN, the sensor nodes have a limited transmission range and their processing and storage capabilities as well as their energy resources are limited. A triple umpiring system has already been proved for its better performance in WSNs. The clustering technique is effective in prolonging the lifetime of the WSN. In this study, we have modified the ad-hoc on demand distance vector routing by incorporating signal-to-noise ratio (SNR) based dynamic clustering. The proposed scheme, which is an efficient and secure routing protocol for wireless sensor networks through SNR-based dynamic clustering (ESRPSDC) mechanisms, can partition the nodes into clusters and select the cluster head (CH) among the nodes based on the energy, and non CH nodes join with a specific CH based on the SNR values. Error recovery has been implemented during the inter-cluster routing in order to avoid end-to-end error recovery. Security has been achieved by isolating the malicious nodes using sink-based routing pattern analysis. Extensive investigation studies using a global mobile simulator have shown that this hybrid ESRP significantly improves the energy efficiency and packet reception rate as compared with the SNR unaware routing algorithms such as the low energy aware adaptive clustering hierarchy and power efficient gathering in sensor information systems.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.763-767
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• 2005

RAID는 디스크 배열 상에 데이터를 이중으로 저장하거나 패리티를 같이 사용하는 기법으로 디스크에 장애가 일어났을 경우 이를 복구하는 구조로 되어 있다. RAID5는 읽기와 큰 데이터 쓰기 접근을 수행하는 2차 저장 장치에서 높은 신뢰성과 비용 효과를 갖는다. 그러나 RAID5는 작은 크기의 데이터 쓰기에 대하여 패리티를 다시 계산하고 유지하는데 소비되는 오버헤드 때문에 성능이 저하된다. 본 논문에서는 패리티 로깅 기법에 의한 파일, 스트라이핑 크기에 대한 RAID5의 읽기/쓰기 성능을 비교 시스템의 성능을 개선한다.

• 펄프종이기술
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• 제43권1호
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• pp.65-73
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• 2011

The fibrous raw materials in packaging-grade paper production in Korea were mainly obtained from waste paper. The use of recycled paper has both positive and negative impacts in papermaking process. The primary positive impacts are the environmental protection and manufacturing cost reduction, and the negative impacts are the quality reduction in paper quality and the accumulation of heavy metals and other pollutants in wet- and dry-end process. This study was carried out to consider the optimum acid decomposition system with the highest recovery rate for the analysis of heavy metals in packaging-grade paper. The open digestion system using Kjeldahl apparatus and the closed digestion system using microwave oven for decomposing the organic materials in paper were compared. In both open and closed digestion method, the combination of nitric acid, hydrochloric acid and hydrogen peroxide showed higher recovery rate than using only nitric acid alone because the presence of Cl- ions in hydrochloric acid stabilizes ligand formation with metal ions. KOCC was observed to have the highest heavy metal content among the recycled paper samples. The heavy metal contents decomposed with the closed digestion system were relatively higher than with open digestion system.

• 한국지진공학회논문집
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• 제23권6호
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• pp.329-339
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• 2019

The strategy for the management of earthquakes is shifting from post recovery to prevention; therefore, seismic performance management requires quantitative predictions of damage and the establishment of strategies for initial responses to earthquakes. Currently, seismic performance evaluation for seismic management in Korea consists of two stages: preliminary evaluation and detailed evaluation. Also, the priority of seismic performance management is determined in accordance with the preliminary evaluation. As a deterministic method, preliminary evaluation quantifies the physical condition and socio-economic importance of a facility by various predetermined indices, and the priority is decided by the relative value of the indices; however, with the deterministic method it is difficult to consider any uncertainty related to the return-year, epicenter, and propagation of seismic energy. Also this method cannot support tasks such as quantitative socio-economic damage and the provision of data for initial responses to earthquakes. Moreover, indirect damage is often greater than direct damage; therefore, a method to quantify damage is needed to enhance accuracy. In this paper, a Seismic Risk Assessment is used to quantify the cost of damage of road facilities in Pohang city and to support decision making.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권12호
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• pp.4725-4747
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• 2020

Software defined networking (SDN) is considered to be one of the most promising paradigms in the future. To solve the scalability and performance problem that a single and centralized controller suffers from, the distributed multi-controller architecture is adopted, thus forms multi-domain SDN. In a multi-domain SDN network, it is of great importance to ensure a reliable control plane. In this paper, we focus on the reliability problem of multi-domain SDN against controller failure from perspectives of backup controller deployment and controller replication. We firstly propose a placement algorithm for backup controllers, which considers both the reliability and the cost factors. Then a controller replication mechanism based on shared data storage is proposed to solve the inconsistency between the active and standby controllers. We also propose a shared data storage layout method that considers both reliability and performance. Besides, a fault recovery and repair process is designed based on the controller backup and shared data storage mechanism. Simulations show that our approach can recover and repair controller failure. Evaluation results also show that the proposed backup controller placement approach is more effective than other methods.