• Journal of the Korean Chemical Society
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• v.39 no.8
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• pp.657-665
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• 1995

The oxidation of various benzyl ethers and benzyl alkyl ethers to benzoates has been studied in two-phase system of $CH_3CO_2Et$ and aqueous NaOCl (6.6 mol eq.). The oxidant N-oxo-4-methoxy-2,2,6,6-tetramethylpiperidium bromide (N-oxoammonium salt) was prepared in situ and recycled by addition of 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl (0.03 mol eq., 4-methoxy-TEMPO), co-catalyst KBr (0.03mol eq.) and second oxidant NaOCl. Thus the catalytic amount of 4-methoxy-TEMPO was used. An adjustment of the pH value of below 8.0 was also required for this reaction with 2.5 hr of reaction time at 0∼5$^{\circ}C$. Under these conditions benzyl ethers were oxidized to benzoates. The selectivity of oxidation of benzyl alkyl ethers is dependent on the acidity of hydrogen and steric effect of alkyl group.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.139-145
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• 2015

This paper compare the VSCA (Variable stepsize Square Contour Algorithm) and VSDA (Variable stepsize Square contour Decision directed Algorithm) adaptive equalization algorithm that is used for the minimization of the intersymbol interference which occurs in the time dispersive channel for the transmission of 16-QAM signal.. In the SCA, it is possible to compensates the amplitude and phase in the received signal that are mixed with the intersymbol interference by the constellatin dependent constant by using the 2nd order statistics of the transmitted signal. But in the VSCA and VSDA, it is possible to the improving the equalization performance by varing the stepsize using the concept of distance adjusted approach for constellation matching. We compare the performance of the VSCA and VSDA algorithm by the computer simulation. For this, the equalizer output signal constellation, residual isi, maximum distortion and MSE were used in the performace index. As a result of computer simulation, the VSCA algorithm has better than the VSDA in every performance index.

• Development and Reproduction
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• v.20 no.3
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• pp.187-196
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• 2016

The objective of the current study was to determine acute plasma stress responses in two size groups of juvenile Epinephelus akaara (average body weight: $8.4{\pm}2.1$ and $3.3{\pm}0.6g$; 150 and 120 days after hatch, respectively) exposed to abrupt salinity drops (from 34 practical salinity unit, PSU seawater to 18, 10 PSU (experiment 1) or 26, 18, 10 PSU (experiment 2), respectively). Plasma glucose, glutamic oxalate transaminase, glutamic pyruvate transaminase, red blood cell counts, and gill histology were determined during 72 h exposure. Significantly increased plasma glucose, glutamic oxalate transaminase levels, and red blood cell counts were observed in fish exposed to 18 or 10 PSU. Histological changes, such as hyperplasia and lifting of epithelium in the gill secondary lamellae, were also observed in fish exposed to 18 or 10 PSU at 72 h post-drop. E. akaara exposed to sudden salinity drops to 18 or 10 PSU still seems to undergo the primary adjustment phase before fish reaches a new homeostasis, whereas fish exposed to 26 PSU seems to mount osmotic changes. Therefore, the no observed adverse effect levels for 72 h acute salinity challenge was 26 PSU in our study, and salinity drop to 18 PSU and below can possibly cause acute adverse effect, in which fish could be vulnerable to additional stresses such as a temperature changes or handling stress.

• 한국해양학회지
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• v.29 no.1
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• pp.50-63
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• 1994

A three-dimensional time-dependent coastal ocean model experiment of two different turbulence parameterizations is conducted. One of the turbulence parameterization is the constant eddy-mixing formulation, C1, and the other a stratification dependent eddy-mixing formulation, C2. The flow in C2 in strongly baroclinic, and limits vertical mixing of fresh and saline waters. The outflow discharged from an estuary is highly inertial and form a strong front of plume in C2 than that in C1. Because of the stronger outflow in C2, supercritical flow state, for which the near surface outflow velocity exceeds the baroclinic phase speed, can exist off the mouth of the estuary. The adjustment process of flow in the less saline waters are quite different for C1 and C2, which is dictated by the strongly baroclinic nature of the flow in C2.

• Journal of Korean Traditional Oncology
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• v.20 no.1
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• pp.31-44
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• 2015

Background : The purpose of this study is to investigate the efficacy and safety of the circadian delivery schedule of fluorouracil or capecitabine based chemotherapy for advanced colorectal cancer. Patients and methods : A meta-analysis was performed using individual data from eight international randomized clinical trials, especially phase II or III trials, comparing 5-fluorouracil, or capeticabine in chronomodulated or conventional schedule. The data from 8 studies was composed of 692 patients receiving chronomodulated chemotheray and 684 patients receiving conventional chemotherapy. The main end point was response rate. Results : Response rate was insignificantly different from each group (RR 1.14, 95%CI 0.74-1.74, p=0.55). Overall survival and progresseion-free survival were not significant either. Chemotherapy induced anemia, diarrhea, and nausea/vomiting were worse in the chronotherapy group, with statistic significance respectively. On the other hand, chemotherapy induced thrombocytopenia, stomatitis, peripheral neuropathy, and dermatotoxicity were better but they were not statistically significant results. Conclusions : Patients lived longer but not significantly on chronomodulated chemotherapy rather than on conventional chemotherapy. Patients on chronomodulated chemotherapy experienced adverse events more. The chronomodulated chemotherapy schedule needs adjustment of its delivery schedule and further research is required.

• Women's Health Nursing
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• v.11 no.1
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• pp.58-66
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• 2005

Purpose: The purpose of this study was to identify the patterns of activities of daily living (ADL) functional status and to examine the relationships between sense of coherence(SOC), depression, and uncertainty in gynecologic cancer patients who were receiving chemotherapy. Method: A prospective, longitudinal design with repeated measures was utilized. Women reported depression, SOC, and uncertainty at the beginning of the first cycle of chemotherapy, and they recorded ADL functional status everyday for two consecutive treatment cycles. the The instruments used were the Karnofsky Performance Status Index, Orientation to Life Questionnaire, Beck Depression Inventory, and Mishel Uncertainty in Illness Scale-Adult Form. Result: Data from 42 women showed that the ADL functional status during the second cycle was better than that of the first cycle with significant improvement each week. However, it did not completely recover to the baseline level even three weeks after the treatment ended in both cycles. SOC was correlated with depression(r=-.64, p<.001) and uncertainty(r=-.62, p<.001). Uncertainty was related to depression (r=.66, p<.001) and to functional status during the second cycle(r=-.45, p<.05), while the scores of the functional status during the two cycles were not related. Conclusion: Changing patterns and level of functional status during the treatment phase would be useful information for cancer patients to prepare coping strategies for positive health outcomes.

• Journal of Advanced Navigation Technology
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• v.21 no.6
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• pp.572-578
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• 2017

As the demand of high accuracy positioning for dynamic users increases, Network RTK is actively researched for dynamic users. Network RTK is a system which provides precise positioning in the range of about 50 to 70km radius using carrier phase measurements from several reference stations. By configuring multiple clusters, which provide Network RTK corrections independently, as a single system, it could provide precise positioning for a wider area. In this paper, we have studied how to efficiently operate multiple clusters in the Korean Peninsula. We analyzed the computational load according to the configuration of a multi-cluster system and proposed a method of selecting the main reference station and system infrastructure configuration for efficient operation. In order to analyze the effects of each proposed method, 71 clusters were constructed using the reference stations of the National Geographic Information Institute and simulations were conducted. As a result of the simulation, system computation amount was reduced by 66 % and system configuration cost was reduced by 90 %.

• Journal of Korean Critical Care Nursing
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• v.7 no.1
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• pp.11-23
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• 2014

Purpose: As the number of cases of heart transplantation (HT) and the survival rate have increased, concerns regarding post-HT life have grown. This study was conducted to explore the relationships of perceived social support to the depression and health status of HT recipients. Methods: This descriptive study targeted all recipients who had undergone HT at S University Hospital since 1994, and 32 recipients were recruited. Results: 90.6% of the recipients were men, and the average age at the time of surgery was $47.4{\pm}13.4$ years. The ejection fraction was increased from $18.47{\pm}5.63%$ to $63.25{\pm}7.57%$, and 31 cases of New York Heart Association (NYHA) class III and IV improved to class I or II after HT. The patients reported mild depression even with high perceived social support and improved health status after HT. Among those resource persons who offered support, they reported their spouse, doctors, and nurses as most meaningful to them. Conclusion: This study confirmed the positive effects of HT on the recipients' physical improvement. It also added the discovery that the importance of recipients' subjective perception of social support might be critical for their more successful recovery and adjustment to post-HT life. Focusing on a different approach to social support and types of social resources in the recovery phase is suggested for future studies on quality of life after HT.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.3
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• pp.9-15
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• 2011

The left-turn actuated signal control method has been occurred various problems under the COSMOS. one of problems is a early termination for left-turn phase by u-turn vehicles at left-turn lane. Therefore, the purpose of this study is a development of the efficient left-turn actuated signal control method to improve the problem. This study was considered that setback the left-turn vehicle detector to the start point of u-turn line and adjustment of the passage time. For effective analysis of developed method, Traffic simulation was simulated by T-7F and VISSIM under various traffic conditions. The result was proved that the developed Method improved the effectiveness.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.5
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• pp.1111-1121
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• 2015

Roundabouts face a congestion problem when there are unbalanced traffic conditions, especially during peak times. The congestion at roundabouts results in long delay times and low level of service. Some research has addressed congestion problems of the metering roundabout, however, few studies have focused on the congestion issues of the double signals metering roundabout. This research bridges this gap through analyzing the congestion issues of the Old Belair double signals roundabout in Adelaide. The research proposes a new analysis method based on a four-nodes intersection in order for double signals roundabout analysis to be carried out as follows: firstly, at the modeling stage, a connection of four individual intersections, adjustment of lane geometry, input of directional traffic volumes, priority and phase time set up are proposed. Secondly, for calibration, PFF, critical gap, follow-up headway and extra bunching values have been applied. The results from the analysis show that the new method is able to analyze the delay time, level of service, degree of saturation and allow for further analysis.