• Clinics in Shoulder and Elbow
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• v.17 no.2
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• pp.50-56
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• 2014

Background: To assess the clinical outcomes of short-term oral corticosteroid therapy for impingement syndrome of the shoulder and determine whether it can be substituted as an alternative to the intra-articular injection. Methods: The clinical outcomes of the 173 patients, the oral steroid group (n=88) and the injection group (n=85), were measured at 3 weeks, 2, 4, and 6 months postoperatively. The clinical outcomes were assessed by measuring the the University of California at Los Angeles (UCLA) score, visual analog scale (VAS) and range of motion (ROM) at every follow-up. Any complications and recurrence rate were noted. A relationship between the treatment outcomes and factors such as demographic factors, clinical symptoms and radiographic findings were determined. Results: No difference was observed in VAS and UCLA scores between the two groups, but forward flexion and internal rotation of ROM were significantly improved in the injection group at the 2nd and 4th postoperative month (p < 0.05). At 6th postoperative month, recurrence rate of symptoms was 26% in the oral steroid group and 22% in the injection group. No major adverse effects were observed. When the clinical outcomes of the oral steroid group were compared to either demographic, clinical symptoms, or radiographic findings, UCLA score was found to be significantly low (p < 0.05) in patients with joint stiffness and UCLA score, whereas VAS score was significantly improved in patients with night pain (p < 0.05). Conclusions: Short-term low-dose oral corticosteroid therapy of impingement syndrome showed comparable clinical outcomes to intra-articular injection without any remarkable adverse effects. Low-dose oral steroids can be regarded as a partial alternative to intra-articular injection for the initial therapy of impingement syndrome of the shoulder.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.527-535
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• 2017

Heat management is one of the most critical issues in Polymer Electrolyte Membrane Fuel Cells (PEMFCs) installed inside the fuel cell power pack of a fuel cell battery hybrid UPS. If the heat generated by the chemical reaction in the fuel cell is not rapidly removed, the durability and performance of the fuel cell may be affected, which may shorten its lifetime. Therefore, the objective of this study is to select and propose a proper cooling method for the fuel cells used in the fuel cell power pack of a UPS. In order to find the most appropriate cooling method, the various design factors affecting the cooling performance were studied. The numerical analysis was performed by a commercial program, i.e., COMSOL Multiphysics. Firstly, the surface temperature of the 1 kW class fuel cell stack with the cooling fans placed at the top was compared with the one with the cooling fans placed at the bottom. Various rotation speeds of the cooling fan, viz. 2,500, 3,000, 3,500, and 4,000 RPM, were tested to determine the proper cooling fan speed. In addition, the influence of the inhaled air flow rate was investigated by changing the porous area of the grille, which is the entrance of the air flowing from the outside to the inside of the power pack. As a result, it was found that for the operating conditions of the 1 kW class PEMFC to be acceptable, the cooling fan was required to have a minimum rotating speed of 3500 RPM to maintain the fuel cell surface temperature within an acceptable range. The results of this study can be effectively applied to the development of thermal management technology for the fuel cells inside the fuel cell power pack of a UPS.

• Journal of Yeungnam Medical Science
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• v.12 no.2
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• pp.292-305
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• 1995

This study was carried out to develop a Korean language version of Zung's self-rating depression scale (SDS). The subjects consisted of 173 males and 161 females drawn from various groups of the general population by a cluster of sampling methods. In order to analyze the data on depression scores, Pearson's product moment correlation coefficient method was carried out, as well as reliability and factor analysis, by the SPSS/PC+ program. The results obtained were as follows: The mean average of the total depression scores were $40.60{\pm}8.66$ for the subjects. Thirty-seven subjects (11.1%) showed high depression scores of 50 or over. Test-retest reliability(coefficient r=0.82, p <0.001), internal consistency(coefficient r=0.84, p <0.001) were satisfactory. Factor analysis using oblique technique rotation yielded five factors. The items of confusion, indecisiveness, decreased libido, diurnal variation, and psychomotor retardation were scored higher by the subjects. The items of suicidal rumination, psychomotor agitation, constipation, irritability, and weight loss were scored lower.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.7
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• pp.841-847
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• 2018

Since global energy consumption and demand for energy have dramatically risen, a focus on environmental problems and sustainability has become more important. Clean and renewable energy sources such as offshore wind power generation have received attention among new renewable energy options as alternative energy resources. Due to maintenance and operational perspectives, offshore wind farms have been planned for installation in many coastal waters. However, development of offshore wind farms faces interference from existing maritime traffic along the planned areas. In order to safely and effectively govern marine traffic in the vicinity of wind farms and inner areas, standard criteria are suggested to allow vessels to sail the internal waters of offshore wind farm areas. Therefore, the purpose of this study is to establish allowable criteria for sailing vessels and safety zones for offshore wind farms by investigating the local regulations of various offshore wind farm cases overseas. The commended inner safety zone of wind farms is proposed to be a distance of 150 % of the rotation diameter of the wind turbine rotor and a distance of 200 m from the outer wind turbine for the outer safety zone. Besides this, the allowable criteria for sailing vessels within a wind farm is proposed to have an air draft of 14.47 m south-west wind farm sea areas for a minimum margin to avoid hull contact through evaluation of the tide and height of a wind turbine. further studies will be needed to establish vessel sailing criteria among adjacent offshore wind farms as well as vessel sailing criteria within a single offshore wind farm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.218-226
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• 2018

The purpose of this study was to examine the validity and reliability of the Korean version of the nursing students' perception of instructor caring (NSPIC) scale developed by Wade and Kasper for nursing students. We collected data from 219 nursing students in the 3rd to 4th year at three nursing colleges from June 4 to June 20, 2018. Data were analyzed using SPSS 21.0 and AMOS 21.0. An exploratory factor analysis with varimax rotation was performed, resulting in five factors (respectful sharing, confidence through caring, control versus flexibility, supportive learning climate, appreciation of life's meanings) with a total of 27 items. Confirmatory factor analysis supported good convergent and discriminant validities. In addition, the concurrent validity test confirmed that the K-NSPIC scale was a validity tool as the correlation of the clinical learning environment (CLE) scale appeared as r=.64 (p<.001). The Cronbach's alpha coefficient of the K-NSPIC was .88, and Cronbach's alpha coefficient for each of the five factors was .91, .86, .80, .76, and .85; internal consistency was confirmed. It is significant that the K-NSPIC proved applicable as a useful tool for assessing instructor caring. It is also expected that it will assist in the design of programs to improve the caring ability of instructors.

• Bulletin of the Korean Chemical Society
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• v.7 no.5
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• pp.367-371
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• 1986

Dynamic and equilibrium properties of n-alkane chains immersed in solvent molecules have been investigated by a molecular dynamics method. The n-alkane chain is assumed to be a chain of elements (CH$_2$) interconnected by bonds having a fixed bond length and bond angle, but each bond of the chain is allowed to execute hindered internal rotation. We studied the effect of the number of the chain elements (N$_c$ = 10, 15 and 20) on the equilibrium properties of the system, e.g., the pair correlation functions between a chain element and solvent molecules, g$_{cs}$(r), and between the chain elements, g$_{cc}$(r), and the configurational properties such as the mean-square end-to-end distance < R$^2$ >, the mean-square radius of gyration < S$^2$ >, and the eigenvalues of the moment-of-inertia tensor < S$_i^2$ > / < S$^2$ > (i = 1, 2 and 3). We also studied the dynamic properties of the system, e.g., the autocorrelation function C(A;t) where A = R$^2$(t), = S$^2$(t), or = ${\vec{V}}(t)({\vec{V}}$ = velocity of the center of mass), and the diffusion coefficient D. The g$_{cs}$(r)'s are almost equal irrespective of the change of Nc while g$_{cc}$(r) becomes larger as N$_c$ increases; The MD computed configurational properties < R$^2$2 > and < S$^2$ > were found to be a little different from the values calculated from the statistical equations of < R$^2$ > and < S$^2$ >, it may be due to the fact that our model for the MD simulations includes a long-range volume effect. From the < S$_i^2$ > / < S$^2$ >, it is found that the chain molecule has a nearly spherical shape irrespective of the variation of N$_c$. For the dynamic properties we found that the C(R$^2$;t) and C(S$^2$;t) of lower N$_c$ decay faster than those of higher N$_c$, while the C($\vec V$;t) of the center of mass in the chain is weakly dependent on the N$_c$. The center of mass diffusion coefficient D$_c$ decreases as N$_c$ increases while the end point diffusion coefficient D$_e$ is nearly equal irrespective of the change of N$_c$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.398-407
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• 2021

Firefighters (who are responsible for people's safety) have one of the jobs that are expected to have problems due to aging in the workforce. An increase in the average age of firefighters can lead to serious social problems. The aim of this study is to survey firefighters in Jeollanam-do about their awareness of aging in firefighters, and to propose a plan to prepare them for aging through investigation and analysis of work problems that may occur due to an aging workforce. The survey shows that the higher the age group, the higher the awareness of aging firefighters, and the higher the total work experience and internal/external work experience, the higher the awareness of aging. As a plan to solve various problems that may arise from aging in firefighters, regular operation of physical fitness promotion programs, field work, job rotation, and managerial measures (such as a change of position to an administrative department) are prepared, and drone or robot technology is used. These solutions include the introduction of applied high-tech technologies to firefighting activities, establishment of retirement management policies, and preparation of plans to revitalize the connection to private employment. In order to maximize the applicability of the field, government institutional plans and preparations are essential.

• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.84-92
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• 2022

The electro-hydrostatic actuator (EHA) recently has been used in flight control fields for aircraft because of its benefits of minimizing oil leakage and weight, improving safety, and etc. while independently operating the hydraulic power source and eliminating complex hydraulic piping. The aircraft of which EHA is installed inside, has the thermal management issue of EHA, because of its limited cooling source as compared with the aircraft which installs the traditional central hydraulic system. So, the thermal analysis model which predicts the thermal characteristics of EHA, is required to resolve this thermal management issue. In this study, an oil circulation circuit inside the hydraulic power module comprised of hydraulic pump and electrical motor for EHA was applied. This is for the purpose of developing the internal rotary group of hydraulic power module, which operates under the conditions of high rotation speed and hydraulic pressure. After formulating an appropriate thermal analysis model, the thermal analysis results with oil cooled or no oil cooled hydraulic control module were compared and reviewed, for the purpose of predicting the thermal characteristics of EHA.

• Sim-seong Yeon-gu
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• v.33 no.1
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• pp.61-80
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• 2018

We investigated whether the 81 items of the Gray-Wheelwright test correctly measure the concept of Jung's typology and aimed to refine the test. Participants (n=431) completed the Gray-Wheelwright test, and the results were analyzed using factor analysis with the varimax rotation and the maximum likelihood extraction method. A pair of opposing attitudes, introversion/extroversion, or one of the two pairs of opposing functional types, thinking/feeling or intuition/sensation, was labeled to the extracted factor according to the majority type of the items in the factor. The minority items or items not included in any factors were excluded from making a short form of the Gray-Wheelwright test with 45 items. We used intraclass correlation (ICC) coefficient and Cronbach's alpha for the test-retest reliability and internal consistency of the test, respectively. The newly developed short form of the Gray-Wheelwright test measured the Jung's personality types well, which was comparable to the original one while reducing time and effort required for the testing.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.2
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• pp.47-53
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• 2024

Purpose : This study investigated the effects of concentric and eccentric contractions on muscle strength using an isokinetic dynamometer (ID) in college students in their 20s. It aimed to understand the impact of differences between the dominant and non-dominant sides on strength asymmetry and to elucidate the clinical implications of these differences to establish an appropriate posture and environment for patients. Methods : The experiment was conducted with 30 healthy adult participants. Prior to the experiment, participants underwent a warm-up targeting the shoulders, and efforts were made to eliminate factors that could potentially influence the measurement results. Subsequently, the maximum safe range of motion of shoulder joint abduction, extension, and flexion was measured using an isokinetic muscle function testing device. Muscle strength was assessed using concentric and eccentric contractions alternating between the dominant and non-dominant sides, and paired sample t-tests were used for the analysis. Results : There was no significant difference between bilateral peak torques for eccentric contraction in shoulder joint abduction, extension, and flexion (p>0.05). There was also no significant difference between bilateral peak torques for concentric contraction in shoulder joint abduction, extension and flexion (p>0.05). Conclusion : This study found no statistically significant difference in muscle strength between the dominant and non-dominant sides during concentric and eccentric contractions. However, previous studies have shown significant differences between the dominant and non-dominant sides during eccentric and concentric contractions during internal shoulder rotation in the general population, as well as significant differences in the upper trapezius muscle. Therefore, further research is needed to support the application of different intensities for bilateral muscle strengthening exercises in clinical practice.