• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.11a
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• pp.57-60
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• 2003

As the business dependency to information systems and the frequency of the large scale disasters increase, implementing the disaster recovery center has been a common practice. However, since there has been little quantitative decision method for the distance between the data center and the disaster recovery center, the distance decision has been commonly made by qualitative guidelines. In this research, the decision method for the optimal distance between the data center and the disaster recovery center is developed, using the cost analysis including the operation cost and the expected disaster cost. An illustrative numerical example is provided.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.8
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• pp.629-635
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• 2008

Recently, microturbines have received attention as a small-scale distributed power generator. Since the exhaust gas carries all of the heat release, the microturbine CHP (combined heat and power) system is relatively compact and easy to maintain. Generating hot water or steam is usual method of heat recovery from the microturbine. In this work, a heat recovery unit producing hot water was installed at the exhaust side of a 30 kW class microturbine and its performance characteristics following microturbine power variation was investigated. Heat recovery performance has been compared for different operating conditions such as constant hot water temperature and constant water flow rate. In particular, the influence of water flow rate and hot water temperature on the recovered heat was analyzed.

• Journal of Marine Life Science
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• v.6 no.2
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• pp.117-123
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• 2021

Post-disturbance recovery pattern of subtidal soft corals-macroalgae mixed community and the role of water depth were investigated. The experiment was conducted in a subtidal rock wall of Munseom, Jeju Island, Korea for 2.5 years. Artificial disturbance was done at established treatment plots at depths of 10, 15 and 20 m and were then compared with undisturbed control plots. After disturbance, recovery of soft corals was very slow, whereas macroalgae quickly occupied the plots and reached a similar level as the control in 6 months, and this pattern was consistent at all water depths. This unbalanced speed of recovery caused higher macroalgae establishment than soft corals in treatment compared to control plots, indicating a possible phase shift in the community structure. This study provides an important implication for the necessity of monitoring the influence of disturbance at a larger scale, from a conservation perspective of soft corals in Jeju coast.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.12
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• pp.1535-1542
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• 2012

A Heat Recovery Steam Generator(HRSG) is the main component of a Combined Cycle Power Plant(CCPP). It is a very large structure that is made from relatively thin metal sheets. Therefore, the structural integrity of an HRSG is very important to ensure safe operation during plant lifetime. In particular, thermal deformation and thermal fatigue have been revealed as the main causes of the mechanical degradation of an HRSG. In order to prevent unexpected damage, safety evaluation based on a large-scale analysis is necessary. Therefore, this study aims to improve the safety of HRSG by using Finite Element Analysis(FEA) results derived from large-scale analysis. Furthermore, the modified design is verified by comparing it with the original one. This result will be used as basic data for improving the safety of a vertical-type HRSG.

• Journal of Digital Contents Society
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• v.12 no.1
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• pp.133-139
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• 2011

Structured P2P (peer-to-peer) networks have received much attention in research communities and the industry. The data stored in structured P2P networks can be located in a log-scale time without using central severs. The link-structure of structured P2P networks should be maintained for keeping log-scale search performance of it. When nodes join or leave structured P2P networks frequently, some links become unavailable and search performance is degraded by these links. To sustain search performance of structured P2P networks, periodic link recovery scheme is generally used. However, when the link recovery period is short or long compared with node join and leave rates, it is possible that sufficient number of links are not restored or excessive messages are used after the link-structure is restored. We propose the adaptive link recovery determination algorithm to maintain the link-structure of structured P2P networks when the rates of node joining and leaving are changed dynamically. The simulation results show that the proposed algorithm can maintain similar QoS under various node leaving rates.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.4
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• pp.297-305
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• 2012

In recent large-scale semiconductor manufacturing clean rooms, the energy consumption of outdoor air conditioning systems to heat, humidify, cool and dehumidify incoming outdoor air represents about 45% of the total air conditioning load required to maintain a clean room environment. Therefore, the energy performance evaluation and analysis of outdoor air conditioning systems is useful for reducing the outdoor air conditioning load for a clean room. In the present study, an experiment was conducted to compare the energy consumption of outdoor air conditioning systems with a simple air washer, an exhaust air heat recovery type air washer and a DCC return water heat recovery type air washer. It was shown from the present lab-scale experiment with an outdoor air flow of 1,000 $m^3/h$ that the exhaust air heat recovery type and DCC return water heat recovery type air washer outdoor air conditioning systems were more energy-efficient for the summer and winter operations than the simple air washer outdoor air conditioning system and furthermore, the DCC return water heat recovery type one was the most energy-efficient in the winter operation.

• KSBB Journal
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• v.21 no.1 s.96
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• pp.1-10
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• 2006

The recovery and purification of a paclitaxel from plant cell cultures is essential to commercial process. This review describes a large-scale recovery and purification method for producing paclitaxel, to guarantee high purity and yield from plant cell cultures. Also, the process of separation and purification is optimized in conjunction with a extraction step, pre-purification, purification, and polishing (drying) as an integrated process to meet final product quality requirements such as purity, residual solvents, product morphologies, impurities, bacterial endotoxin, etc. This information is very useful for production and quality control of pharmaceuticals in commercialization step.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.674-680
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• 2023

The brine and seawater are important and largely untapped sources of critical trace metals and elements. The coupling of selective recovery of trace metals from seawater/brine with desalination plants gives an added advantage of energy credits to desalination plants and as well as reduce the cost of desalinated water. In this paper, status review on recovery of important trace metals and other alkali metals from seawater is presented. The potential of Indian desalination plants for recovery of trace metals, based on recovery ratio of 0.35 is also highlighted. Studies carried out by the process based on adsorption using Radiation Induced Grafted (RIG) polymeric adsorbents and then fractional elutions are presented. The fouling factors due to bio fouling and dirt fouling have been estimated for various locations of interest through field trails. The pay loader in the form of compact Contactor Assembly with minimum pressure drop, for loading specially designed radiation grafted sorbent in leaflet form has been briefed, as required for plant scale facility. The typical conceptual process design details of farm assembly of project CRUDE are described.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.2
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• pp.109-118
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• 2014

The purpose of this study was to compare the effectiveness of rehabilitation therapy with natural recovery in patients who had dysphagia due to stroke. Swallowing functions were examined on a total of 98 patients with stroke-caused dysphagia based on a videofluoroscopic swallowing study (VFSS) for 8 weeks. The each group was evaluated with DOSS, DSS and FOSS to assess swallowing ability in the first week and re-evaluated in the $8^{th}$ week during the session for investigating the recovery status. The author compared the above initial data and follow-up data using a Mann-Whitney U test, Kruskal-Wallis test and Wilcoxon's Signed Rank test, ANCOVA to confirm statistically controlling for the effects of other continuous variables, performed by IBM SPSS Statistics 20.0 for windows. There was statistically significant recovery in the experimental group except measure of DOSS (p>0.05). In the control group, it showed improvement in all the scales(p<0.05). After terminating each session, the comparison of the two group of patients showed statistical significant differences in DSS and FOSS(p<0.05). These results suggest that possibility of natural neurologic recovery has positive effects on early stage of dysphagia caused by stroke.

• The Korean Journal of Pain
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• v.11 no.2
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• pp.247-252
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• 1998

Background: Tonsillectomy is one of the most common operation in children. Postoperative pain and its sequelae are universal complaints of the patients. The purpose of this study was to evaluate the effects of nalbuphine on the posttonsillectomy pain in children. Methods: Fifty-four pediatric patients undergoing tonsillectomy under general anesthesia were randomly allocated to one of the 3 groups 1) control group who received no analgesics, 2) received IV nalbuphine before induction of anesthesia and 3) received IV nalbuphine after both tonsillectomy. In postanesthetic recovery room, comfort level in all patients was assessed using the objective pain scale (OPS). Systolic blood pressure, diastolic blood pressure and heart rate were measured at just before and immediately after extubation and postanesthetic recovery room. Results: The pain scale score in group 2 was significantly lower than group 1, but no significantly different with group 3. There were no significant differences in blood pressure among three groups. The heart rate in group 2 and 3 was significantly lower than group 1 only at immediately after arriving recovery room. Conclusions: Administration of nalbuphine before induction is more effective on postoperative pain control after tonsillectomy in children.