• Journal of Acupuncture Research
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• v.31 no.2
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• pp.99-109
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• 2014

Objectives : The purpose of this study was to analysis the relationship between hours of smartphone use and neck pain in university students. Methods : A survey of 2,353 university students was conducted in Gyeonggi province and Incheon city using a self report questionnaire from April 1 to 11 2013. The questionnaire of questions regarding the hours of using smartphone, mainly used function in participant's smartphone and neck discomfort degree. Neck disability index(NDI) was used to evaluate degree of pain. The collected data were analyzed with the t-test and Kendall's tau test using the SPSS 21.0 program and R 3.1.0, respectively. Results : 1. Almost all of the survey participants(99.07 %) were smartphone users. 66.97 % of them answered that they use their smartphone daily more than 2 hours and 48.18 % of them answered that they use their smartphone 10 to 30 minutes everytime they use it. 2. The overall distribution of NDI scores was 'no disability(0~4 score, 62.92 %)', 'mild disability(5~14 score, 32.85 %)', 'moderate disability(15~24 score, 1.19 %)'. As a result of t-test, we found that the average NDI score for female students was significantly higher than the average NDI score for male students(p<0.05). 3. The Kendall's tau test revealed that total time spent daily using smartphones has a strong positive correlation with 'pain intensity', 'lifting', 'reading' 'headache', 'concentration', and 'driving'(p<0.05) in NDI. Also, time duration of one time smartphone usage has a strong positive correlation with 'pain intensity', 'lifting', 'reading', 'headache', 'concentration', 'work', and 'recreation'(p<0.05). 4. The Kendall's tau test revealed that total NDI scores have a significantly strong positive correlation with both of total time spent daily using smartphones(p<0.05) and time duration for one time smartphone usage(p<0.05). This results imply that long-time use of smartphone has a strong relationship with neck pain. Conclusions : The results of the study would be a good starting point for future studies to reduce the risks of chronic neck pain caused by smartphone usage.

• Clinics in Shoulder and Elbow
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• v.9 no.2
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• pp.176-180
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• 2006

Purpose: Although surgical arthroscopic repair of rotator cuff has become much more common as surgeons have developed proficient techniques, it is still technically difficult. The purpose of this study was to evaluate the clinical results and the usefulness of mini-open repair in large and massive size tears. Materials & Methods: From January 2000 to December 2004, sixteen patients were treated with mini-open repair. There were 10 male and 6 female patients with the average age of 62.5 years. The size of tear was massive in 4 cases and large in 12 cases. All tears were repaired with metal anchor sutures. The mean duration of follow-up period was 23 months. Postoperative results were evaluated based on American Shoulder and Elbow Society scoring system. Results: Five patients showed excellent results, five good, and two fair in large tears while one patient showed excellent result, one good, and two fair in massive tears. Poor outcome was not seen during the follow-up period. There was no significant relationship between the patient's age and the size of tear, and postoperative results. However, the relationship between the duration of symptomatic period in preoperation and postoperative results showed significant correlation. Conclusion: Mini-open repair combined with the preservation of deltoid and early rehabilitation is clinically useful in large and massive size rotator cuff tear patients treatment.

• Journal of the Korean Society of Food Culture
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• v.16 no.2
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• pp.109-117
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• 2001

Judging from the studies carried out by Dr. Jo, Yong Jin on the Koreans' faces, Koreans divided into two constitutions according to their facial features and heritages. The one population is the Northern lineage whose ancestor migrated from Siberia in ice age. In order to survive in cold climate, they have developed a high level of metabolic heat production. Cold adaptation for preventing heat loss results in a reduction in the facial surface area with small eyes, nose and lips. The other population is the Southern lineage who is the descent of native in Korean peninsular. They have big eyes with double edged eyelids, broad nose and thick lips. It is generally believed that both genetic and environmetal factors influence eating behaviors. Although we can't recognized their heritage that may contribute to the metabolism and eating behavior, we commonly recognize their physiological heritage acceding to their facial features. In order to investigate the relationship among the size and shape of facial feature, the eating behavior, anthropometric measurement in female college students, the eating behaviors was measured during an instant-noodle lunch eaten in a laboratory setting at the ambient temperature of $23^{\circ}C$. The anterior surface area of left eye and length of right eye were positively correlated with the difference between the peak postprandial and the meal-start core temperature. The surface area of lower lip also negatively correlated with the meal-start core temperature and meal duration. In addition, the total lips' area was positively correlated with the difference between the peak postprandial and the meal-start core temperature and negatively correlated with the meal duration. However anthropometric measurements were not related with the size of facial features.

• Journal of Korean Society of Forest Science
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• v.102 no.3
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• pp.463-466
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• 2013

We examined relationship between rainfall and triggering of shallow landslides in South Korea, based on hourly rainfall data for 478 shallow landslides during 1963-2012. Rainfall intensity(I) and duration(D) relationship was analyzed to obtain the I-D threshold for the initiation of a shallow landslide using the quantile regression analysis. The I-D threshold equation from in this study is: $I=9.64D^{-0.27}$($4{\leq}D{\leq}76$), where I and D are expressed in millimeters per hour and hours, respectively. In addition, rainfall criteria were proposed to predict the potential to cause landslides, based on values of I-D and cumulative rainfall derived from quantile regression analysis. Our findings may provide essential data and important evidences for the improvement of landslide warning and evacuation system.

• Biomolecules & Therapeutics
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• v.24 no.2
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• pp.115-122
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• 2016

Sleep, which is an essential part of human life, is modulated by neurotransmitter systems, including gamma-aminobutyric acid (GABA) and dopamine signaling. However, the mechanisms that initiate and maintain sleep remain obscure. In this study, we investigated the relationship between melatonin (MT) and dopamine D2-like receptor signaling in pentobarbital-induced sleep and the intracellular mechanisms of sleep maintenance in the cerebral cortex. In mice, pentobarbital-induced sleep was augmented by intraperitoneal administration of 30 mg/kg MT. To investigate the relationship between MT and D2-like receptors, we administered quinpirole, a D2-like receptor agonist, to MT- and pentobarbital-treated mice. Quinpirole (1 mg/kg, i.p.) increased the duration of MT-augmented sleep in mice. In addition, locomotor activity analysis showed that neither MT nor quinpirole produced sedative effects when administered alone. In order to understand the mechanisms underlying quinpirole-augmented sleep, we measured protein levels of mitogen-activated protein kinases (MAPKs) and cortical protein kinases related to MT signaling. Treatment with quinpirole or MT activated extracellular-signal-regulated kinase 1 and 2 (ERK1/2), p38 MAPK, and protein kinase C (PKC) in the cerebral cortex, while protein kinase A (PKA) activation was not altered significantly. Taken together, our results show that quinpirole increases the duration of MT-augmented sleep through ERK1/2, p38 MAPK, and PKC signaling. These findings suggest that modulation of D2-like receptors might enhance the effect of MT on sleep.

• Journal of Korean Biological Nursing Science
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• v.1 no.1
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• pp.56-70
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• 1999

The purpose of this study was to determine the effect of physical activity on bone mineral density(BMD), and osteoporosis risk factors in Korean women. A convenience sample of 115 women completed the survey questionnaire which included the items of physical activity, osteoporosis risk facors, and demographic background. Distal radial BMD was evaluated using DTX-200. The data were analyzed using frequency, percentage, t-test, Pearson Correlation Coefficient, logistic regression, ANOVA, stepwise multiple regression by SPSS WIN. The sample ranged in age from 31 to 78 years(mean=47.67 old). 91.8% were married, 72.2% were housewives, and mean monthly income was 1,094,900won. Mean explain of the women was 1.21MET, and 50.4% of the women were in the physically inactive group. Brisk walking and mountain climbing were frequently cited activities. 1.8% of the subjects smoked, and 27.5% used alcohol. Average daily intake of milk was 1.17 cups and that of caffeine, 1.13 cups. Age, body weight, monthly income, BMI, education level, duration after menopause, menstration status and caffeine. intake were correlated with BMD. In the relationship between the physical activity and BMD, the physically active group showed a higher level of BMD than the physically inactive group. Significant MET decreased was noted with an age increase. In the stepwise multiple regression analysis, body weight, duration after menopause, and the number of children were identified as the most important risk factors. Conclusively, physical activity could be a beneficial effect in the reduction of osteoporosis in Korean women, considering a positive relationship between physical activity and radial BMD.

• Journal of muscle and joint health
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• v.9 no.1
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• pp.40-52
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• 2002

This study was conducted to describe disease characteristics, psycho-social factors and treatment behavior of patients with lupus and to analyze relationships anions these variables. The subjects were consisted of 120 lupus patients at G university hospital in Seoul. Data were collected by means of structured interview with questionnaires, and analyzed by using frequencies, $x^2$test, t-test, ANOVA, and correlation. The results were as follows; 1. The average age of the subjects was 31.34 years and average duration of suffering lupus was about 7.3years. Severity of symptoms was moderate and the disturbance of living activities was at the very low level. 2. Self-efficacy score of lupus patients was high, and life satisfaction was at moderate level. 3. Dosage for most of the subjects was about twice a day. 16.7% of them took non-prescribed medicine and only 27.5% perform exercise. 4. Positive correlation was shown among symptom, discomfort of living activities, self-efficacy and life satisfaction, while there was negative correlation among symptom and self-efficacy, symptom and life satisfaction, discomfort of living activities and self-efficacy, and discomfort of living activities and life satisfaction. In addition, exercise showed significant relationship with discomfort of living activities, and non-prescribed medicine showed significant relationship with discomfort of living activities and self-efficacy. These results show that lupus is a chronic disease of long suffering duration among young people. Severity of the symptom was at modest level, while discomfort of living activities were relatively insignificant. However self-efficacy was relatively high. Furthermore self-efficacy has influences on symptom and discomfort of life activities, just as exercise affects discomfort of life activities. Therefore it is required to examine further measures for continuous exercise.

• Nuclear Engineering and Technology
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• v.45 no.3
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• pp.393-400
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• 2013

Concrete undergoing early frost damage in cold weather will experience significant loss of not only strength, but also of permeability and durability. Accordingly, concrete codes like ACI-306R prescribe a minimum compressive strength and duration of curing to prevent frost damage at an early age and secure the quality of concrete. Such minimum compressive strength and duration of curing are mostly defined based on the strength development of concrete. However, concrete subjected to frost damage at early age may not show a consistent relationship between its strength and durability. Especially, since durability of concrete is of utmost importance in nuclear power plant structures, this relationship should be imperatively clarified. Therefore, this study verifies the feasibility of the minimum compressive strength specified in the codes like ACI-306R by evaluating the strength development and the durability preventing the frost damage of early age concrete for nuclear power plant. The results indicate that the value of 5 MPa specified by the concrete standards like ACI-306R as the minimum compressive strength to prevent the early frost damage is reasonable in terms of the strength development, but seems to be inappropriate in the viewpoint of the resistance to chloride ion penetration and freeze-thaw. Consequently, it is recommended to propose a minimum compressive strength preventing early frost damage in terms of not only the strength development, but also in terms of the durability to secure the quality of concrete for nuclear power plants in cold climates.

• Animal Bioscience
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• v.34 no.10
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• pp.1717-1722
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• 2021

Objective: Stroking calves during the postnatal period could effectively improve human-calf relationships. The objective of this study is to examine how daily calf stroking frequency during the postnatal period affects the establishment of human-calf relationships. Methods: Six calves were stroked by a trainer for 6 minutes once daily for 5 days after birth (D1). Six calves were stroked by a trainer for 3 minutes twice daily for 5 days after birth (D2). A further four calves were stared at but not stroked as the control group. The overall stroking or staring duration was the same for all groups, at 6 min/d and 30 min over 5 days. The tests for reactions to the stationary trainer in an unfamiliar environment and avoidance distance measurements for an approaching trainer were conducted at 1 month and 3 months after the treatment. Results: Calves in both stroking groups approached significantly closer to the stationary trainer, vocalized less, and looked at the trainer shorter than the control group at 1 month. However, at 3 months, there was no significant difference between the D1 and the control group, whereas the D2 approached significantly closer to the trainer and vocalized less, and looked at the trainer for a shorter time than the control group. For the avoidance distance, the trainer could approach closer to both stroking groups than the control at 1 month, however, there was no difference among groups at 3 months. Conclusion: Our results suggested that the difference in the calf stroking procedure affected the established human-calf relationships, even though the total stroking duration was the same for all stroked calves. It is likely to be more effective to stroke more frequently than intensively when the aim is to establish better human-calf relationships within limited labor time.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.1
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• pp.29-43
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• 2022

This study measures the realized rate of return of venture capital(VC) fund at the level of investment agreement(as opposed to fund level returns reported by most of the relevant studies). It also measures the stock price return of the VC's portfolio firms (unlisted start-ups) at firm level(as opposed to fund returns) and its variance for the first time using unique data of the VC funds held by the Korean Venture Capital Association. Results of the analysis confirm that VC fund returns exceed individual stock price returns. Additionally, it is confirmed that VC portfolio firms exhibit a positive relationship between risk and return measured by total risk. Finally, we find that stock price returns at firm level are lower than that implied by the associated levels of risk. Consequently, this may make individual investors hesitate to directly buy unlisted startups' stocks even when investment in individual startup companies guarantees high risk-high returns relationship.