• Journal of KIISE:Computer Systems and Theory
• /
• v.26 no.8
• /
• pp.949-956
• /
• 1999

이 논문에서는 ATM (Asynchronous Transfer Mode) 방식의 초고속망의 장애 발생 시 이용자 연결의 QoS (Quality of Service)를 고려하여 복구할 수 있게 하는 보호 망 설계 방안을 제시한다. 제시한 설계 방안에 기초한 비용과 복구 특성을 분석과 모의 실험을 통해 알아본다. 제안하는 망에서의 복구는 분리 VP 그룹 (Disjoint Virtual Path Group, DVPG) 을 사용하는 상태 독립적 (State- independent) 방식으로 복구된다. ATM 망의 운용 및 보호 VP 할당과 용량 배정 문제를 정의하고 이를 바탕으로 최소의 비용을 갖는 VP 망을 설계한다. 망의 고장 시 기존 노드간의 VP 연결은 미리 할당된 링크 또는 노드 분리 보호 VP 경로를 따라 간단한 복구 알고리즘에 의해 빠르게 복구된다. QoS의 고려는 추가 비용을 필요로 하지만 정확한 이용자 연결의 복구를 실현하며, 분리 VP 그룹의 적용은 비용을 상승시키지만, 빠른 복구와 복수의 고장에 대처할 수 있는 방안이 된다.Abstract A cost evaluation of protection scheme for VP-based ATM network is presented here and its related characteristics are evaluated. The proposed and evaluated scheme is a state-independent restoration scheme using a disjoint path group. For fast and simple restoration of failed connections, link disjoint or node disjoint VP groups (DVPG) were utilized in this paper. A VP assignment and capacity planning problem is formulated. When failure occurs, the failed working VPs are switched to the protection VPs of disjoint path groups with a simple restoration scheme. And, cost evaluation and restoration characteristics are presented. The consideration of multiple QoS (Quality of Service) levels and disjoint path group protection scheme require additional network cost but acquire fit and fast restoration.

• Journal of Korean Academy of Nursing
• /
• v.14 no.1
• /
• pp.1-20
• /
• 1984

This study was attempted to evaluate and explain the correlation between stress and utilization of Dispensary, Frequency of absence, Frequency of accident as the health condition of bluecollared workers. The subjects for this study were 260 workers selected conveniently from 360 workers working at one chemical manufacturer located in Seoul. The dataas measure the Stress was collected through SRRS (The Social Readjustment Rating Scale) which is developed by Holmes ＆ Rahe (1976) from 27th July to 10th August, 1983. The data of Utilization of Dispensary and Frequency of Accident were brought out from the record of Dispensary during past 8 months. The Frequency of Abscence from January to August were collected through diligence and indolence cards of each department. All collected data were analysed based on the SPSS (Statistical Package for the Social Science) program. The results of the study are as follows: 1. The average of Utilization of Dispensary was 7.4, Frequency of abscence 14.6, frequency of Accident 0.4. 2. The average score of Stress was 134 (minimum : 0, maximum : 593, Standard deviation : 109. 3) It can be considered as a slight stressed group by the requlations of Holmes and Rahe. 3. According to the analysed results of correlation between Stress and the Utilization of Dispensary, Frequency of Absence, frequency of Accident, the Utilization of dispensary and stress were significantly related (r= .1955, p<.001), the Frequency of Absence (r=.0284, p >, 05), and the Frequency of Absence (r=.0284, p>.05), and the Frequency of Accident (r= .0831, p>.05) were not significantly related with Stress. 4. In the relation between general characters of subjects and the Utilization of Dispensary, 20 to 25 aged group, women, single, christian, lent-house dwelling, 1 to 5 years employed group used at a high ratio. 5. In the relation between general character of subjects and the Frequency of Absence, men, 51 to 55 aged group, 21 to 25 years employed group indicated high Frequency, and other char-noters were not significantly related. 6. In the relation between general characters of subjects and the Frequency of Accident, women. single, 20 to 25 aged group, catholic, lent-house dwelling, below 1 year employed group showed high frequency. 7. Stress showed a significant difference only with a religion. Catholic group represented mode-rate stressed scored 209.67, and not significantly related with other general characters.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.6
• /
• pp.1-6
• /
• 2014

The IoT (Internet of Things) is considered as a core technology to realize interconnected world. At this, companies composing ICT industry and standard organizations make efforts to accelerate it. IETF CoRE(Constrained RESTful Environment) working group standardized CoAP (Constrained Application Protocol) for the constrained device. CoAP has RESTful architecture and CoAP option is provided to use forward-proxy. The forward-proxy is used to translate protocol and perform requests on behalf of the client. However, communication between Internet based client and LLN(Low-power and Lossy Network) based CoAP server architecture has limitations to deploy real IoT service. In this architecture, problems like response delay, URI assignment and DoS attack can be occurred. To solve these problems, we propose the reverse-proxy based system. We consider both of static IoT and mobility IoT environments. Finally, our proposed system is expected to provide efficient IoT service.

• International Journal of Fluid Machinery and Systems
• /
• v.9 no.3
• /
• pp.245-255
• /
• 2016

The alternating flow hydraulics (AFH) had demonstrated the unique features in the past. One of the most well-known inventions was the hydraulic machine-gun synchronizer, which had become the standard equipment of airplane during World War I. The studies on the AFH between 1960 and 1980 had trigged many researchers' interests and reached the summit. The disadvantages of the AFH like low efficiency and cooling difficulty had prevented the further development. Few people are engaged in studying the AFH at present. However, the unique characteristics of the AFH inspire the researchers to continuously explore the new special suitable applications. The overviews of the AFH and the new potential application in the geotechnical testing field have been discussed in this paper. First, the research results of the AFH in the past have been summarized. Then, the classifications of the AFH have been introduced in detail according to the working principle, the number of hydraulic transmission pipelines and the mode of input energy. The advantages and the disadvantages of the AFH have been discussed. A novel potential suitable application in the soil test field has been presented at last. The detailed designing ideas of a new dynamic trixial instrument have been given, which will be a more innovational and energy-saving plan according to the current studies. A series of simulation experiments have been done. The simulation results show that the proposed scheme for the new dynamic trixial instrument is feasible. The paper work will also give some inspirations in the reciprocating motion control system.

• Journal of Korean Academy of Nursing
• /
• v.40 no.5
• /
• pp.736-746
• /
• 2010

Purpose: This study was done to identify the distribution and related factors for stage of change for wearing hearing protection devices (HPDs) by workers in environments with high noise. Predictors of Use of Hearing Protection Model and Trans-theoretical Model were tested. Methods: The participants were 755 workers from 20 noisy work places in Busan and Gyeongnam. Data were collected from January to April 2008 using self-administered questionnaires, and analyzed using multiple logistic regression. Results: There were significant differences in social mode (OR=1.35, 95% CI: 1.06-1.73) between precontemplation/contemplation and preparation stage, in males (OR=2.36, 95% CI: 1.24-4.51), workers with high school education or less (OR=1.39, 95% CI: 1.28-2.78), shift workers (OR=1.50, 95% CI: 1.02-2.21), workers who previously worked in noisy places (OR=1.39, 95% CI: 1.20-2.34), and workers who had previous hearing examinations (OR=1.89, 95% CI: 1.25-2.85), in the social model (OR=1.59, 95% CI: 1.42-1.78), and self-efficacy (OR=1.05, 95% CI: 1.02-1.08) between workers in preparation and action stages, in length of time working in noisy work places (OR=2.26, 95% CI: 1.17-4.39), social model (OR=1.66, 95% CI: 1.33-2.08), and perceived benefit (OR=0.95, 95% CI: 0.93-0.97) between action and maintenance stage. Conclusion: Social model was a common factor showing differences between two adjacent stages for wearing HPDs. The results provide data for developing programs to encourage workers to wear HPDs and application of these programs in work settings.

• Journal of Korea Multimedia Society
• /
• v.9 no.11
• /
• pp.1474-1482
• /
• 2006

Recently, it is advanced about the variable research of IPv6 and the wireless sensor network. However, the existed researches are not enough about the internetworking technology between the wireless sensor network and the Internet based on IPv6 for supporting ubiquitous service. Accordingly, this paper proposes two internetworking models for connecting the wireless sensor network and Internet based on IPv6. The relay router in the first model and the sink node of the wireless sensor network in the second mode] were used as a gateway. Then we analyze and compare with two internetworking models. Additionally we construct the test-bed connected between the wireless sensor network and KOREN(KOrea advanced REsearch Network) based on IPv6 using the first model. And we verified the operation of the test-bed by experiments.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38B no.4
• /
• pp.247-256
• /
• 2013

According to the complete standard document for PHY/MAC layer of visible light communication through the IEEE 802.15.7 WG on Sept. 2011, visible light communication lays a good foundation for developing a variety of application services. Thus, visible light communication moves to the advanced research period for developing application services, but most of applications are limited only to PtP service model. However, PtMP communication environment for VLC is required to accommodate more various applications. In this paper, we analyze an effect of key parameters on network performance in the star topology based visible personal area network system. We implement a simulator with considering attributes of PHY and MAC layer which are defined by IEEE 802.15.7 standard documents, and analyze the VLC performance.

• Microbiology and Biotechnology Letters
• /
• v.15 no.6
• /
• pp.430-435
• /
• 1987

A chitin-immobilized enzyme amyloglucosidase(AMG) and a bacterium Zymomonas mobilis were coentrapped in alginate gel beads. Ethanol production was performed in a packed bed column reactor in a simultaneous saccharification and fermentation(SSF) mode using liquefied sago starch as a substrate. It was found that this process eliminated product inhibition and reverse reaction of glucose enhancing the rate of saccharification and ethanol production. At a low dilution rate of D = 0.11 hr$^{-1}$, the steady-state ethanol concentration was 46.0g/$m\ell$ (96.8 % of theoretical yield). The maximum ethanol productivity was 17.7g/$m\ell$, h at D = 0.83 hr$^{-1}$ when the calculation was based on the total working volume. The continuous production of ethanol was maintained stably over 40 days without problems in this reactor system.

• Journal of Technology Innovation
• /
• v.20 no.2
• /
• pp.1-28
• /
• 2012

The government-supported research institutes' system seems to face a turning point as the country's innovation system, shaped in the industrialization process, now reveals its own limitations. This makes the transformation of the innovation system unavoidable. Korea began to emerge as a leader in several technological areas including semiconductor, TFT-LCD, and handset, in a few cases even outpacing advanced countries. This has changed the very nature of the problems and questions to be resolved. This study analysed the structural limitations and challenges of government-supported research institutes focused ETRI. In a nutshell, The innovation system of government-supported research institutes seems to face a situation where the new innovation environment is conflicting and competing with the legacy of the past: governance, planning, budget, personnel, evaluation system. There are needs for change and thus tries to achieve a innovation system transition and build a new vision and management system including a new mode of working for post-catchup innovation.

• Analytical Science and Technology
• /
• v.8 no.4
• /
• pp.575-582
• /
• 1995

A new analytical procedure using a serial dual electrode detector was developed for the analysis of amino acids and proteins. Bromine was generated at the upstream electrode and detected by the downstream electrode. The presence of amino acids and proteins was shown to lower the downstream current but with no apparent effect on the upstream current. This indirect mode of detection can be applied to the determination of amino acids and proteins which are electrochemically inactive or too large to be accessible to the electrode surface for electron exchange. The method is shown capable to determine various amino acids (cystine, tyrosine, lysine, tryptophan, glycine, methionine and arginine) and proteins (cytochrome c, hemoglobin, HAS, a-Amylase, Conalbumin I, Catalase and Myglobin) with linear working range for amino acids between $10^{-6}$ to $10^{-3}M$ and total proteins between $10^{-7}$ to $10^{-3}M$. The method has been applied for the analysis of amino acids and total protein in food using Flow Injection Analysis with results obtained comparable to those using the traditional analytical procedure. Use of pulse generation technique was shown to produce a more stable flow injection analysis peaks for repetitive determination than the use of conventional constant current method which showed increase of the background current after determination over 200 minutes. The pulse method was found to give stable baseline even after 400 minutes. Thus, the method is shown able to provide a suitable analytical procedure for automatic analysis of amino acids and proteins in food by flow injection analysis.