• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.10
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• pp.942-951
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• 2004

This paper presents the results of a theoretical study of the effect of radiation during free convective laminar film boiling for methanol/water binary mixtures on an isothermal vertical wall at atmospheric pressure. With the well-known boundary layer theory as a basis, a theoretical model has been formulated into consideration for mass diffusion at liquid phase. The equations are numerically solved by a similarity method to investigate the effects of radiation emissivity on the surface with various parameters such as wall superheat and composition of more volatile component at liquid phase far from the wall. From the results, the distributions of the physical quantifies are investigated in both phases. New correlations are proposed to predict the heat transfer coefficient of binary mixtures. It is shown that the proposed correlations are in good agreement with numerical results and with Bromley's correlation within maximum $11\%$ errors. It is also found that as the wall superheat is increased, radiation effect becomes more important.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.3
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• pp.265-272
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• 2004

Based on the T-method, a new scheme for predicting air flow rate distribution in a bathroom exhaust system is developed. Introduction of individual duct route enables us to disintegrate a complicated multi-fan ductwork into a set of simultaneous single-fan subsystems. The scheme is validated via the analysis of a well-posed test problem, showing physical consistency. In order to demonstrate the utility and capability of our method, the bathroom ventilation system in a 20-story residential building is selected as an example. Under the typical design condition, the air flow rate of each exhaust fan at the balancing point is successfully predicted, and such information can lead to an engineering estimation for the overall system performance. While some deficiencies in ventilation are found at bathrooms at lower floors with 6mmAq-rated exhaust fans, they disappear over the whole building by using fans of enhanced static pressures, 7 and 8mmAq. Finally the present scheme seems to be useful for practical design of multi-branched, multi-fan ventilation systems.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.11
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• pp.867-873
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• 2006

Vertical falling liquid film is extensively used in heat and mass transfer processes of many applications, such as evaporative coolers, cooling towers, and absorption chillers. In such cases, it is required that the falling film spreads widely in the surface forming thin liquid film to enlarge contact surface. An addition of surface active agent to a falling liquid film or hydrophilic surface treatment affects the fluid physical properties of the film. Surfactant addition not only decreases contact angle between the liquid and solid surface but also changes the surface from hydrophobicity to hydrophilicity. In this study, the effects of contact angle on falling film characteristics over a vertical surface have been investigated experimentally. The contact angle is varied either by an addition of surfactant to the liquid or by hydrophilic surface treatment. It is found that the wetted area is increased and film thickness is decreased by the hydrophilic treatment as compared with those of other surfaces. With this hydrophilic treatment, the falling liquid film spreads out widely in the surface. As surfactant concentration is increased, wetted area is also increased and the film thickness is substantially decreased.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.1180-1185
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• 2006

Modern people spend most of time at indoor space, such as office or classroom. Especially, occupants are exposed to the airtight indoor air quality (IAQ) for a long time, At present, many studies on the air-conditioning systems are more focused on the individual thermal comfort than the thermal efficiency due to increase of the concern of health. There are several factors which are influenced thermal comfort, such as temperature, humidity, convection and air movement, etc. Also, the individual factor, such as age, gender, Physical constitution and habit, should be considered. The 4-way cassette type air conditioner is known to bring out better performance about thermal comfort than the traditional one. This study is performed on the higher ceiling environment than the common buildings or classrooms. Also, this study analyzed on the Indoor thermal comfort by diffusing direction of 4-way cassette air conditioner with various discharge angles, $45^{\circ},\;50^{\circ},\;55^{\circ}$ and $60^{\circ}$. Using a commercial code, FLUENT, three-dimensional transient air thermal flow fields are calculated with appropriate wall boundary conditions and standard $k-{\epsilon}$ turbulence model. Results of velocity and temperature distributions are graphically depicted with various discharge angles.

• Journal of Korean Academy of Nursing
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• v.20 no.1
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• pp.88-117
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• 1990

The purposes of this study are to delineate a profile of the state of a stroke patient's adaptation at 3 months after hospitalization and to explore the relationship between the level of adaptation and the variables which influence the adaptation of hemiplegic patients. To these ends, theoretical framework was derived basically from the stress adaptation model. The basic assumption underlying the level of adaptation is influenced by the presenting focal, contextual and residual stimuli. This group of stimuli is further operationalized and represented by a perception of stress. which is the perceived effect of the disability and by the mediating variables such as sociodemographic factors as an external conditioning variables and perceived social support and hardiness personality characteristics as an internal intervening variables. The dependent varibales in this study is the level of physical, psychological and social adaptation and is hypothesized to be a function of the interaction between 3 sets of variables namely, the perceived disability effect, external conditioning variables and internal intevening varibles. A total of fourty three subjects from 3 general hospitals in Seoul were observed and interviewed with the aid of 7 structured instruments. The data were collected twice on each subject : first at the pre-discharge period arid at 3 months post-discharge from hospital for the second time. The study was carried out for the period from February to August, 1988. The instruments used for the study include 4 existing scales and 3 scales developed by the researcher for this study. They are : 1) The ADL dependency scale and the scale of the clinical physical functions for the assessment of physical adaptation. 2) the SDS(self report of depression) to measure the level of psychological adaptation. 3) The scale for the amount of social activities for the measurement of the level of social adaptation. 4) The scale for the perceived effect of disability for the measurement of the focal stimuli. 5) The health related hardiness scale and the perceived interpersonal support self evaluation list(ISEL) for the measurement of the hardiness personality character and the perceived social support. The data obtained were analyzed using percentage, oneway ANOVA, Pearson coefficients correlation and stepwise multiple regression. The findings provide valuable information about the present level of physical adaptation at 3 months after discharge. The patient revealed a decreased ADL dependency and lowered limitation of physical function as compared with pre - discharge state. Psycholcgically, the average degree of depression at follow up was within normal range of depression. Socially, the amount of social activities was very low. The one way ANOVA and the correlational analysis revealed the relationship between the 3 sets of variables and the adaptation level as follows : 1) The perceived disability effect was related to the degree of the depression and the amount of social activities but was not related to the physical adaptation. 2) Among the sociodemographic variables, sex and education were related to the difference of ADL dependency and the change of physical function. These factors indicate that women more than men and educated more than the less educated were found more independent. The education was also related to the degree of depression suggesting that the higher the educational level, the more well adapted the patients were both physically and psychologically. Age, marital status and job state were not found to be related to the patient's adaptation level. 3) Among the internal intervening variables, the health related hardiness characteristic was related to the differences of ADL dependency, physical functions and the social activities, indicating that the higher the hardiness character the higher the level of physical and social adaptation. 4) The perceived social support, another internal intervening variable, was related to the degree of depression and the social activities. This data suggest that the higher the perception of social support, the better adapted the patients were psychogically and socially. In summarizing the results of the correlational analysis, the level of physical adaptation was influenced by sex, the years of education and the hardiness character. The level of psychological adaptation was influenced by the years of education, the perceived disability effect and the perceived social support. And the level of social adaptation was influenced by the perceived disability effect, the hardiness character and the perceived social support. The stepwise multiple regression analysis shows findings as follows : 1) The most important factor to explain the difference of ADL dependency was sex, indicating females were more independent than males. 2) The most important factor to explain the difference of physical function and the degree of depression was the patient's education level. 3) The strongest explaining factor for the amount of social activities was perceived self esteem(one of the subconcepts of perceived social support). Thus the most important factors influencing the level of adaptation were found to be sex, education, the hardiness character and self esteem. From the above findings, the significance of this study can be delineated as follows : 1) Corroboration of the assumed relationship between the various variables and the adaptation level as suggested in the conceptual model. 2) Support for the feasibility of the cognitive approach for nursing intervention such as hardness character training, counselling and teaching for self-care in the chronic patients.

• Journal of Korean Physical Therapy Science
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• v.13 no.2
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• pp.7-16
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• 2006

The purpose of this study was to investigerate the changes of isokinetic muscular function in elderly people who have been to take from osteoarthritis in both knee joints after 36 weeks' rehabilitative therapy programs. In this study the subjects were 20 women residing in S-Tower(n=10) and H-welfare Town(n=10) respectively. The rehabilitative group(equal to experimental group) had taken part in exercise program 5 days per week. And then was performed by warm up, workout(involving aerobic exercise and weight training), cool down, physical therapy(cryotherapy, TENS, ultrasound). Also its programs were classified in conditioning phase($0{\sim}12$ weeks), improvement phase($13{\sim}24$ weeks), and maintenance phase($25{\sim}36$ weeks) respectively. The results of inspections were as followed: In the isokinetic muscular function, there were significant differences in right leg's flexor and extensor in $60^{\circ}$/sec. And there were significant differences in right leg's flexor and left leg's extensor in $180^{\circ}$/sec. At last, there were significant differences in right leg's flexor and left leg's extensor in $240^{\circ}$/sec. In other words, the rehabilitative programs for 36 weeks could increase the muscular function in elderly with OA. In conclusion, the rehabilitative programs of this paper has shown the positive results, which involved in the muscular function variables in elderly people with OA in both knee.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.1
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• pp.77-84
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• 2024

Objectives: Interventions promoting physical exercise and healthy habits in workplaces have been shown to be effective in reducing risk factors for metabolic syndrome. This study was conducted to examine the effects of an individualized conditioning exercise program of IT company office workers with or at higher risk of metabolic syndrome. Methods: A total of 444 IT company office workers with or at higher risk of metabolic syndrome participated in a 3-month conditioning exercise program. Body composition data using bioelectrical impedance analysis and cardiopulmonary data using cardiopulmonary exercise testing from 53 individuals (mean age: 34.8 ± 7.1 years, sex : 21% female, height : 170.4 ± 6.8 cm, weight : 75.2±12.2 kg, body mass index : 25.8±3.3 kg/m²) who have successfully completed pre-test, intervention, and post-test were analyzed. The 12 weeks intervention encompassed: (1) health counseling (2) supervised exercise(endurance-based, aerobic exercise, or circuit training once a week for 50 minutes at heart rate reserve(HRR) of 77-95%) (3) self-directed exercise and biweekly health screening checks. Results: The results indicated a significant decrease in body weight, body fat mass and body mass index, respectively. Moreover, VO₂peak, AT VO₂ and AT Time significantly improved, respectively. Resting blood pressure(SBP/DBP) showed positive changes but were not statistically significant. We observed the correlation between characteristics of participants and rate of changes in cardiopulmonary outcomes of participants, there are no significant correlation. These results indicate positive changes in body composition and cardiorespiratory fitness parameters following individualized conditioning exercise program. Conclusions: Individualized workplace exercise program for preventing metabolic syndrome can lead to improvements in body composition and cardiorespiratory fitness.

• Korean Journal of Applied Biomechanics
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• v.21 no.3
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• pp.335-343
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• 2011

Patellofemoral pain syndrome is the most common problem involving the knee, accounting for 25% of knee injuries. Repetitive, overuse activities cause increased force at the patellofemoral joint, resulting in pain during flexion and extension activities. Most research have been conducted in exploring the patellofemoral compressive force in gait, squat and lunges, even though in real cases, possibilities in landing exist. The purpose of this study was to compare the differences in patellofemoral compressive force according to two different height. Sixteen collegiate male students(age: 22.25 ${\pm}$ 3.30 yrs, height: 177.25 ${\pm}$ 4.44 cm, weight: 77.50 ${\pm}$ 8.18 kg) were chosen. The subjects performed drop landings in 45 cm, 60 cm. The findings demonstrated that higher height showed peak knee extension moment, quadriceps contraction force, patellofemoral compressive force with increased VGRF. Regarding the patellofemoral joint compressive force, it increased by quadriceps contraction force with knee flexion during landing, yet, it showed no difference in maximal knee flexion. To minimize patellofemoral joint stress and reduce the likelihood of developing PFPS, we recommend that predesigned quadriceps and hip muscle group strengthening are needed during conditioning and training.

• Journal of Korean Physical Therapy Science
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• v.3 no.1
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• pp.919-927
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• 1996

Recently sports injuries are increasing due to the development of sports leisure industries as well as the increase of exercising population, and the study for sports injuries is needed more than before. Then the author studied the reasons for injuries, incidence rate, sites and sorts of sports injuries for the middle and high school football players during one year period from Jan. to Dec. 1994. The study subjects were 319 middle and high school players in Pusan and the method was questionnaire method. The results were as follows; 1. The average injury rate due to football play was 3.3 times per person for the 319 subjects during the last one year, and it was highest in goalkeeper as 4.6 times by position. 2. 68 % of the subjects did not receive periodic health examination, 74.9 % wore body protectors. The sports injuries due to football play occurred most commonly in soil play-ground(79.6 %), during training(52.3 %), and in winter time(33.7 %). 3. The commonly occurred injuries by motion were coalition(39.2 %), tackle(12.9 %), dribble (11.4 %) in order; those by sorts were contusion(34.4 %), sprain (32.9 %), spasm(9.0 %) ; and those by body portions lower extremities(82 %), trunk(17.6 %), upper extremities(12.5 %). 4. The frequently used treatment area was home care as in 42.7 % ; treatment methods were physical therapy, acupuncture/moxacautery, rest, operation in order; choices of treatment method were recommendation by coach/manager, and that by medical professional was the lowest as in 2.2 %. 5. If sports injury occurred during play, coach or manager let the players take rest in 56.2 %, but emergent management by medical professional was done only in 1.9 %. The return to play was decided mostly by the player himself(52.8 %), but that decided by a doctor was only in 1.0 %. In conclusion, to lessen the sports injuries due to football play, annual physical check-up, strengthening of play rules, improvement of playground, conditioning exercise, regulation of body protectors, and preventive training for expected injuries behaviors should be done and the decision to return to play and emergent management should be done by a medical professional as well. Football player, sports injury, injured body portions, sorts of injury, treatment method.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.483-486
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• 1995

With a view to increase utility of ethanol fractionated fish skin gelatin as a food source, the effect of gelation condition on physical properties of the gelatin was investigated. The physical properties of gelatins treated with or without ethanol were improved with a concentration of gelatin increased. The properties such as gel strength, melting point and gelling point of 10% gelatin sol or gel were reached to maximum at pH 6.0 in ethanol treated gelatin and pH 5.0 in non treated one, respectively. Gel strength and melting point of both gelatin gels chilled for long time at low temperature were superior to those of both gelatin gels chilled for short time at high temperature. Gel strength, melting point and gelling point of ethanol treated gelatin gel or sol prepared under optimized gelation conditioning were superior to those of non treated one.