• Korean Management Science Review
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• v.26 no.2
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• pp.19-35
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• 2009

This paper investigated performance of the Markowitz's portfolio selection model with applications to Korean stock market. We chose Samsung-Group-Funds and KOSPI index for performance comparison with the Markowitz's portfolio selection model. For the most recent one and a half year period between March 2007 and September 2008, KOSPI index almost remained the same with only 0.1% change, Samsung-Group-Funds showed 20.54% return, and Markowitz's model, which is composed of the same 17 Samsung group stocks, achieved 52% return. We performed sensitivity analysis on the duration of financial data and the frequency of portfolio change in order to maximize the return of portfolio. In conclusion, according to our empirical research results with Samsung-Group-Funds, investment by Markowitz's model, which periodically changes portfolio by using nonlinear programming with only financial data, outperformed investment by the fund managers who possess rich experiences on stock trading and actively change portfolio by the minute-by-minute market news and business information.

• Journal of the Korean Ceramic Society
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• v.46 no.2
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• pp.155-160
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• 2009

The reliability could be one of the essential properties for multilayer ceramic capacitor (MLCC) using in various electronic devices and the concentration and mobility of oxygen vacancy would play important role in the reliability. To investigate the migration behavior of oxygen vacancies, thermally stimulated depolarization current (TSDC) is adopted. In dielectric material of X5R MLCC, the TSD-Current peak observed around 150$^{\circ}C$ and 200$^{\circ}C$ which represented the migration of oxygen vacancy. Substituting Yttrium for Dysprosium in X5R MLCC showed higher migration activation energy and lower TSD current density.

• Journal of Korean Clinical Nursing Research
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• v.25 no.1
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• pp.25-33
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• 2019

Purpose: This study was done to develop a program to promote maternal role confidence and maternal attachment for mothers of premature infants and to evaluate the effects in a neonatal intensive care unit (NICU). Methods: This program was developed through a literature review and validation of an expert group, and tested with 60 preterm infants (experimental group 30, control group 30) in a NICU in South Korea. Data were collected from December 2017 to March 2018 and analyzed using descriptive statistics, t-test, $x^2-test$ and Fisher's exact test with the SPSS/Win statistical program. Results: Maternal role confidence for the experimental group increased significantly compared to the control group (t=3.22, p=.002). Maternal attachment in the experimental group increased significantly compared to the control group (t=2.30, p=.025). Conclusion: The program developed in this study should be effective in promoting maternal role confidence and maternal attachment in mothers of premature infants.

• Radiation Oncology Journal
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• v.33 no.3
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• pp.217-225
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• 2015

Purpose: To investigate the outcomes of patients with spinal metastases from hepatocellular carcinoma (HCC), who were treated by stereotactic body radiotherapy (SBRT). Materials and Methods: This retrospective study evaluated 23 patients who underwent SBRT from October 2008 to August 2012 for 36 spinal metastases from HCC. SBRT consisted of approximately 2 fractionation schedules, which were 18 to 40 Gy in 1 to 4 fractions for group A lesions (n = 15) and 50 Gy in 10 fractions for group B lesions (n = 21). Results: The median follow-up period was 7 months (range, 2 to 16 months). Seven patients developed grade 1 or 2 gastrointestinal toxicity, and one developed grade 2 leucopenia. Compression fractures occurred in association with 25% of the lesions, with a median time to fracture of 2 months. Pain relief occurred in 92.3% and 68.4% of group A and B lesions, respectively. Radiologic response (complete and partial response) occurred in 80.0% and 61.9% of group A and B lesions, respectively. The estimated 1-year spinal-tumor progression-free survival rate was 78.5%. The median overall survival period and 1-year overall survival rate were 9 months (range, 2 to 16 months) and 25.7%, respectively. Conclusion: SBRT for spinal metastases from HCC is well tolerated and effective at providing pain relief and radiologic response. Because compression fractures develop at a high rate following SBRT for spinal metastases from primary HCC, careful follow up of the patient is required.

• Biomolecules & Therapeutics
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• v.11 no.3
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• pp.178-182
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• 2003

The clinical use of once daily aminoglycoside (ODA) dosing has been increased because of the potential therapeutic advantages of this dosing regimen. To evaluate the optimal sampling times of ODA dosing method in a clinical setting, the study was prospectively conducted in a total of 28 patients with UTI. All of the patients were intravenously administered gentamicin at a dose of 7 mg/kg over 60 minutes and randomly divided into two groups. Blood was collected at 0, 2, and 6 hours in Group A and at 1, 2, and 6 hours in Group B after the end of 1-hour infusion. The pharmacokinetic parameters (Ke, Vd and Cmax) obtained using the 0, 6 hour levels and 2, 6 hour levels in Group A were statistically different while those of 1, 6 hour levels and 2, 6 hour levels in Group B were similar. This finding indicated that the distributional phase of ODA is completed within 1 hour following the end of the I-hour infusion. If we are allowed to collect only two blood samples in ODA considering patients comfort and the analytical cost of drug, the first one should be drawn after 1 hour following the end of infusion to obtain adequate pharmacokinetic information.

• Child Health Nursing Research
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• v.16 no.2
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• pp.144-155
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• 2010

Purpose: This study was done to develop and test a home-based discharge program. Methods: The study design was a pretest-posttest nonequivalent nonsynchronized quasi-experimental design. Participants were mothers of premature infants on oxygen therapy at home. The participants, 49 mothers, were assigned to either the experimental group (24) or control group (25). Data collection was conducted from September, 2008 through February, 2009. Maternal confidence and anxiety were measured using a questionnaire. Chi-square test, t-test and Repeated Measures ANOVA were used to analysis the data. Results: Two hypotheses, "Maternal confidence in the experimental group will be higher than that of the control group" and "Perceived anxiety level in the experimental group will be lower than that of the control group", were set up and both hypotheses were supported as there was a statistically significant difference between the two groups. Conclusion: It suggests that the discharge program developed in this study is an efficient intervention method to boost maternal confidence of the mothers with premature infants and to decrease their anxiety; therefore, this program is expected to be of use in nursing interventions.

• Journal of Korean Clinical Nursing Research
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• v.18 no.1
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• pp.111-125
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• 2012

Purpose: The purposes of this study were to develop a navigation program for newly diagnosed cancer patients and to evaluate its effects. Methods: The navigation program was based upon Professional Navigation Framework. Patients were asked to complete self-administered questionnaires on satisfaction, distress, anxiety and depression for evaluating the program. Results: The navigation program consisted of facilitating two concepts: continuity of care and empowerment of patients. Information-education package, telephone counseling and navigator's phone number were provided to the newly diagnosed cancer patients for care continuity. Self-care diary and emotional support by telephone counseling were provided to the patients for empowerment of patients. A total of 163 patients - 78 control and 85 experimental participants - were included in the study. The mean scores of satisfaction, distress, anxiety and depression had no statistical differences between the two groups after program implementation. In patients with longer waiting days, the experimental group with the navigation program showed higher relational continuity than the control group after program implementation(p=.023). In patients with longer waiting days or with higher distress, satisfaction of relational continuity was improved after program implementation in the experimental group. Conclusion: The navigation program in this study has applied the concept of patient navigation into oncology clinical setting in Korea. Navigation program can play a significant role in assisting patients navigating across the care continuum.

• Annals of Surgical Treatment and Research
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• v.95 no.6
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• pp.333-339
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• 2018

Purpose: The purpose of this study was to describe the long-term effects of stenting in patients with hepatic venous outflow obstruction (HVOO), who underwent living donor liver transplantation (LDLT). Methods: Between January 2000 and December 2009, 622 adult patients underwent LDLT at our hospital, and of these patients, 21 (3.3%) were diagnosed with HVOO; among these patients, 17 underwent stenting. The patients were divided into early or late groups according to the time of their HVOO diagnoses (cutoff: 60 days after liver transplantation). Results: The median follow-up period was 54.2 months (range, 0.5-192.4 months). Stent insertion was successful in 8 of 10 patients in the early group and 6 of 7 in the late group. The 5-year primary patency rates were 46% and 20%, respectively. In both groups, patients with recurrent HVOO at the beginning showed kinking confirmed by venography. Patients who carried their stents for more than 3 years maintained long-term patency. There was no significant difference in spleen size between groups; however, when the groups were compared according to whether they maintained patency, spleens tended to be smaller in the patency-maintained group. Conclusion: Unlike stenosis, if kinking is confirmed on venography, stenting is not feasible in the long term for patients with LDLT.

• Journal of Yeungnam Medical Science
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• v.40 no.4
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• pp.412-418
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• 2023

Background: The aim of this study was to evaluate the risk factors for prostate-specific antigen (PSA) persistence in pathological stage T3aN0 prostate cancer (PCa) after robot-assisted laparoscopic radical prostatectomy (RALP). Methods: A retrospective study was performed on 326 patients with pT3aN0 PCa who underwent RALP between March 2020 and February 2022. PSA persistence was defined as nadir PSA of >0.1 ng/mL after RALP, and the risk factors for PSA persistence were evaluated using logistic regression analysis. Results: Among 326 patients, 61 (18.71%) had PSA persistence and 265 (81.29%) had PSA of <0.1 ng/mL after RALP (successful radical prostatectomy [RP] group). In the PSA persistence group, 51 patients (83.61%) received adjuvant treatment. Biochemical recurrence occurred in 27 patients (10.19%) in the successful RP group during the mean follow-up period of 15.22 months. Multivariate analysis showed that the risk factors for PSA persistence were large prostate volume (hazard ratio [HR], 1.017; 95% confidence interval [CI], 1.002-1.036; p=0.046), lymphovascular invasion (LVI) (HR, 2.605; 95% CI, 1.022-6.643; p=0.045), and surgical margin involvement (HR, 2.220; 95% CI, 1.110-4.438; p=0.024). Conclusion: Adjuvant treatment may be needed for improved prognosis in patients with pT3aN0 PCa after RALP with a large prostate size, LVI, or surgical margin involvement.

• The Korean Journal of Pain
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• v.10 no.1
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• pp.73-76
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• 1997

Background : Epidural anesthesia is now accepted as a popular technique for pain relief and anesthesia. However, accidental dural puncture may occur during placement of the epidural needle. This study was undertaken to evaluate difference of the epidural depth between parturients and non-parturients. Method : Eighty non-parturients receiving epidural anesthesia were assigned to group I, and eighty parturients whose body weight had not yet increased over 15 kg from pregnancy were assigned to group II. With patients in lateral decubitus position, 18 guage Tuohy needle was punctured by approaching at $L_{3-4}$ interspace. Epidural space was identified using loss-of-resistance to air technique. Result : Epidural depth was 4.18 cm and 4.25 cm in group I and group II respectively. There was no significant statistical difference in body mass index(BMI) and ponderal index(PI) (p<0.05), nor in epidural depth between the two groups. Conclusion : Epidural needle need not be placed deeper in parturients than in nonparturients.