• Journal of the Korean Society for Precision Engineering
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• v.3 no.1
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• pp.40-49
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• 1986

Crack, craze and void are common defects which may be found in the bulk of polymeric materials such as either themoplastics or thermosets. The healing phenomena, autohesion, of these defects are known to be a intrinsic material property of various polymeric materials. However, only a few experimental and theoretical investigations on crack, void and craze healing phenomena for various polymeric materials have been reported up to date [1, 2, 3]. This may be partly due to the complications of healing processes and lacking of appropriate theoretical developments. Recently, some investigators have been urged to study the healing phenomena of various polymenic materials since the significance of the use of polymer based alloys or composites has been raised in terms of specific strength and energy saving. In the earlier published reports [1, 2, 3, 4], the crack and void healing velocity, healing toughness and some other healing mechanical and physical properties were measured experimentally and compared with predicted values by utilizing a simple model such as the reptation model under some resonable assumptions. It seems, however, that the general acceptance of the proposed modeling analyses is yet open question. The crack healing processes seem to be complicate and highly dependent on the state of virgin material in terms of mechanical and physical properties. Furthermore, it is also strongly dependent on the histories of crack, craze and void development including fracture suface morphology, the shape of void and the degree of disentanglement of fibril in the craze. The rate of crack healing may be a function of environmental factors such as healing temperature, time and pressure which gives different contact configurations between two separated surfaces. It seems to be reasonable to assume that the crack healing processes may be divided in several distinguished steps like stress relaxation with molecular chain arrangement, surface contact (wetting), inter- diffusion process and com;oete healing (to obtain the original strength). In this context, it is likely that we no longer have to accept the limitation of cumulative damage theories and fatigue life if it is probable to remove the defects such as crack, craze and void and to restore the original strength of polymers or polymer based compowites by suitable choice of healing histories and methods. In this paper, we wish to present a very simple and intuitive theoretical model for the prediction of healed fracture toughness of cracked or defective polymeric components. The central idea of this investigation, thus, may be the modeling of behavior of chain molecules under healing conditions including the effects of chain scission on the healing processes. The validity of this proposed model will be studied by making comparisons between theoretically predicted values and experimentally determined results in near future and will be reported elsewhere.

• Korean Security Journal
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• no.31
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• pp.101-123
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• 2012

The 5 day workweek has become widespread, and more recently, the 40 hour workweek is planned to be implemented to the Korean industry by the government by 2012. It is possible that in the future, we may begin to complain about too much leisure, rather than too much work. There is a need then, for types options in leisure activity, brought about by personal choices and interests. The use of leisure time is a very personal matter. It is deeply related to types with the quality of life. Bagozzi (1981) developed a model discerning among attitude, intention and activity, that attitude affects behavioral intention, and behavioral intention affects activity. So, as behavioral activity has a deep relationship to behavioral intention, participation intention according to leisure types leads to participation in leisure activity. Sports activity and hobby and cultural activity appear to have high participation and it seems that this is reflected in behavioral attitude. Among the types of leisure satisfaction, sport activity satisfaction is associated with a more positive attitude to leisure than other types. With respect to background variables for attitude toward leisure according to leisure satisfaction, the biggest differences in attitude toward leisure were associated with sports activity.

• Journal of the Korean Wood Science and Technology
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• v.23 no.4
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• pp.39-45
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• 1995

The plywoods commonly used as decorative interior materials for the construction are inflammable and so it is a causative factor for making fire accidents, resulting in the destruction of human life and personal properties. Indeed, it is, therefore, required to produce fire-retardant plywoods. In this study, a special grade of defect-free, Kapur plywood was used. Specimens were cut into 3- by 20cm dimensions from 120- by 240- by 0.33-cm panels(thin panel) or 120- by 240- by 0.5-cm panels(thick panel). Some specimens were treated with diammonium phosphate(DAP), but some were not treated with diammonium phosphate to use as control panels. Chemical absorption, drying curves, drying rates and dynamic Young's modulus were investigated. The results were summaries as follows; 1. The specimens were soaked into 19% diammonium phosphate solution by a full cell pressure process and the diammonium phosphate retained in the thin and thick plywoods was 1.409kg/$(30cm)^3$, 1.487kg/$(30cm)^3$, respectively. 2. Diammonium phosphate-treated plywoods were redried with press-drying process at one of either condition dried on the platen($115^{\circ}C$) for a period of time or dried on the platen($50^{\circ}C$) for 3 hrs plus in a dry-oven($30^{\circ}C$) for 24 hrs. or dried on the platen($60^{\circ}C$) for 2 hrs plus in a dry-oven($30^{\circ}C$) for 24 hrs. The drying rate of treated thin specimens dried at $60^{\circ}C$ plus $30^{\circ}C$ and $115^{\circ}C$ only was found to be 0.04 %/min. and 8.53 %/min. Similarly, the drying rate of treated thick specimens were 0.03 %/min. and 6.77 %/min. respectively. 3. It was evident that highly-significantly different drying rate of treated plywoods was observed between plywood thicknesses and platen temperatures and the rate was increased by elevating the platen temperature up to $115^{\circ}C$. Based on the two-way variance analysis, highly significant drying rate was observed from the interaction between plywood thicknesses and platen temperatures. 4. After redrying, the specimens were weighed and reconditioned to a constant weight in a facility maintained temperature ($20^{\circ}C$) and relative humidity(65%) prior to test dynamic Young's modulus. The test revealed that the thin specimens dried at the platen temperature of $50^{\circ}C$, $60^{\circ}C$, $115^{\circ}C$ and untreated specimens showed 1.070E+09 dyne/$cm^2$, 1.156E+09 dyne/$cm^2$, 1.243E+09 dyne/$cm^2$, and 1.052E+09 dyne/$cm^2$, respectively. Likewise, the thick specimens revealed 5.647E+09 dyne/$cm^2$ 5.670E+09 dyne/$cm^2$, 6.395E+09 dyne/$cm^2$ and 5.415E+09 dyne/$cm^2$, respectively. 5. It was evident that significantly different dynamic Young's modulus was observed between the plywood thickness and the platen temperature, but not in the two-way interaction between the plywood thickness${\times}$the platen temperature.

• Journal of Chest Surgery
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• v.49 no.4
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• pp.273-279
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• 2016

Background: The use of extracorporeal life support (ECLS) in the setting of cardiopulmonary resuscitation (CPR) has shown improved outcomes compared with conventional CPR. The aim of this study was to determine factors predictive of survival in extracorporeal CPR (E-CPR). Methods: Consecutive 85 adult patients (median age, 59 years; range, 18 to 85 years; 56 males) who underwent E-CPR from May 2005 to December 2012 were evaluated. Results: Causes of arrest were cardiogenic in 62 patients (72.9%), septic in 18 patients (21.2%), and hypovolemic in 3 patients (3.5%), while the etiology was not specified in 2 patients (2.4%). The survival rate in patients with septic etiology was significantly poorer compared with those with another etiology (0% vs. 24.6%, p=0.008). Septic etiology (hazard ratio [HR], 2.84; 95% confidence interval [CI], 1.49 to 5.44; p=0.002) and the interval between arrest and ECLS initiation (HR, 1.05 by 10 minutes increment; 95% CI, 1.02 to 1.09; p=0.005) were independent risk factors for mortality. When the predictive value of the E-CPR timing for in-hospital mortality was assessed using the receiver operating characteristic curve method, the greatest accuracy was obtained at a cutoff of 60.5 minutes (area under the curve, 0.67; 95% CI, 0.54 to 0.80; p=0.032) with 47.8% sensitivity and 88.9% specificity. The survival rate was significantly different according to the cutoff of 60.5 minutes (p=0.001). Conclusion: These results indicate that efforts should be made to minimize the time between arrest and ECLS application, optimally within 60 minutes. In addition, E-CPR in patients with septic etiology showed grave outcomes, suggesting it to be of questionable benefit in these patients.

• Journal of Families and Better Life
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• v.28 no.1
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• pp.131-143
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• 2010

The purpose of this study is to understand the living culture of transnational married women and to analyze the out door play of children in their hometown. The data was collected through observation from 27th June to 7th July 2008 in Jian, Jilin Province China. The children's play and lifestyles were observed, and data pertaining to the culture of the people were collected by a teacher and staff. We also visited the residents for housing information. The results are given below. 1. They dressed in Korean clothes on festive days and the boys put on a hood. They had eating habits which included cooking for themselves or buying semi-manufactured goods but did not use, instant food. The housing habits involved a combination of cooking and heating by Korean floor heating system(Ondol). They utilized outdoor space to grow vegetables. Those with a fulltime job(teacher) preferred to live in an apartment but an apartment was too expensive. Public utility charges and traffic expenses were cheap. 2. The main festive days are the lunar New Year's Day and Chuseok. The children returned home and enjoyed the festive day with their parents. The language used are Korean language and Chinese. Some Korean words and phrases in Jian Joseonjok have different meanings as compared to how they are used in Korea. A capping ceremony did not to celebrate becoming an adult from an adolescent. Couples performed a wedding ceremony at a wedding hall attended by their parents and invited relatives from both families. The relatives gave the couple a wedding gift. They did not go on a wedding trip as it was not affordable but instead spent their wedding night at a hotel in this culture. When someone dies, they bury the body after cremation. They perform a memorial service for three years on the birthday of the departed. They have a banquet on the 60th birthdays with their relatives and neighbours and are typically presented with a carp for longevity. 3. They understand capitalism and therefore send their children to school to improve their social position. The Korean and Chinese languages are required subjects in school. The students choose a second language(English or Russian). They prefer English class but at the time of this study an English class was not offered at the school in Jian Joseonjok. Therefore the children entered a Chinese school. 4. The children play outdoor games such as Y$\acute{a}$o J$\grave{i}\bar{a}$(要家), X$\grave{i}$ang g$\grave{i}$(象棋), T$\grave{i}\grave{a}$o p$\acute{i}$ j$\grave{i}$n(r)(跳皮節), D$\grave{o}$uch ing g$\grave{u}$n 凍冷根, B$\bar{e}$i B$\bar{e}$i 背背, and soccer. They play games according to the season.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.125-129
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• 2016

Background: Patients with differentiated thyroid cancers (DTC) who receive radioactive iodine-131 (RAI) are released from isolation when their dose rate is below the regulatory requirements. The purpose of this study was establish predicting factors for early release from the isolation facility after RAI administration in patients with DTC. Materials and Methods: This was a prospective study which included 96 (58 females and 38 males) patients with DTC who had received RAI from April 2013 till August 2015. The study was duly approved by the ethical committee of the institute. Patients who had complete information of primary tumor size (PTS), serum TSH, stimulated thyroglobulin level [sTg] with antibodies (IU/ml) at the time of RAI treatment were included. All had a normal serum creatinine level. To attain lower effective half-life good hydration and administration of soft laxative were ensured. Dose rate was measured (immediately, 24 h and 36 h) at 1 meter distance from anterior mid trunk and a dose rate <$50{\mu}Sv/h$ was considered as the releasing criterion. At 24 h 50 patients were released while the remaining 46 patients were released at 36 h. A post-ablative whole body scan (PA-WBIS) was performed 5-8 days after RAI ablation in all patients. Results: Patients released after 24 h were significantly younger, had smaller lesions with higher proportion of papillary cancer, lower sTg, lower sTg/TSH ratio and had received a lower dose of RAI as comapred to those who were discharged after 36 h. Serum TSH and gender were not found to have any significant correlation between two cohorts. ROC and multivariate analysis have shown age ${\leq}37years$, PTS ${\leq}3.8cm$, $RAI{\leq}150mCi$, $sTg{\leq}145ng/ml$ and $sTg/TSH{\leq}1.085$ as strong indepedent predictors for early release. Conclusions: We conclude that younger age (${\leq}37years$), smaller tumor size (${\leq}3.8cm$), lower RAI dose (${\leq}150mCi$), lower sTg (${\leq}145ng/ml$) and a lower sTg/TSH ratio (${\leq}1.085$) are significant independent predictors for release at 24 h after RAI treatment in DTC patients. Effective utilization of these factors could help the treating physicians to use limited number of internment facilities with higher throughput, lower cost and lower psychological stress to patients.

• Journal of Music and Human Behavior
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• v.13 no.1
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• pp.41-60
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• 2016

This study investigated how people who became blind midway through life used music and how these uses differed according to individual factors. Sixty-one late-blind adults aged 40 to 60 years attending six welfare centers for the blind in Seoul and Gyeonggi region participated in this research. Participants were asked to complete a 25-question survey in Braille on music utilization and preference, as well as the purpose of music utilization. The response rate was 87.1%. The results were as follows. First, with regard to listening preference, they reported preferring to listen to upbeat popular music on the radio when resting at home. They liked to sing along to lyrics reminiscent of personal memories. String instruments were preferred when playing an instrument. With regard to the reason for using music, inducing mood change was found to be the biggest reason, followed by seeking enjoyment, comfort, sense of achievement, and sense of belonging. Third, for people with adventitious visual impairments, individual factors, such as gender, level of disability, and period without eyesight, did not reveal any significant differences. Last, participants were found to obtain a higher sense of belonging through music compared to those having low vision. Regarding time without eyesight, it appeared that the shorter the period, the higher the sense of belonging participants had from utilizing music, and vice versa. This study provides fundamental information for organizing an effective music program that can meet the needs and demands of people with adventitious visual impairments.

• Journal of the Korea Institute of Building Construction
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• v.10 no.5
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• pp.45-54
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• 2010

Recently more and more construction projects have become high-rise, complex and intelligent. Accordingly, such projects require an integrated management system for tasks, with a lean approach to construction with work processes for management and productivity. In particular, Construction Information Technology (CIT) fields are concerned with Building Information Modeling (BIM), which represents the process of generating and managing building data during its life cycle. Constructability research has progressed for the project goal which is a cost-time-quality of optimization by integrated construction knowledge and experience. However, the current constructability process has not been performed efficiently, as the existing 2D drawings and papers lack consistent and accurate information, it is difficult to share the contents of work, and the use of information is inefficient. This study proposes that the reformation and enhancement of BIM-based constructability work process can lead to brilliant performance in the framework of the construction phase through achieving collaboration between the design team and the workers at the site.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.386-393
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• 2016

The incidence of gallbladder polyps are increasing due to the extended use of ultrasonography. Although there are various reports on the risk of gallbladder polyps, there are few studies of the relationships among the presence of metabolic syndrome including serum biochemistry, lifestyle and the development of gallbladder polyps. The aim of this study was to determine association of the presence of metabolic syndrome, including serum biochemistry, with the development of gallbladder polyps in the Korean population. Among the health examination examinees, 596 people, who underwent abdominal ultrasonography from January, 2013 to December 2013, were included in this study. Physical measurements also taken, such as height, weight, blood pressure, waist measurement, and BMI. The general characteristics including age, sex, smoking, and drinking as the related factors were checked. At the same time, various blood tests were performed and the fasting blood sugar was analyzed through blood-gathering to determine the presence of metabolic syndrome. Regarding the factors associated with gallbladder polyps, the results showed that being male, smoking, non-drinking were significantly high. In addition, testing positive for HBsAg and an increasing BMI was apparently higher the group with metabolic syndrome than the non-metabolic syndrome group. The highest predictive factors for gallbladder polyps was being male (1.8 times), followed by metabolic syndrome (2.3 times) and testing positive for HBsAg (2.6 times).

• Korean Journal of Community Nutrition
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• v.18 no.6
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• pp.588-598
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• 2013

This study was conducted to assess needs of educational mobile application (App) development for nutritional management and information on pregnant women. A total of 105 pregnant women were investigated on general characteristics, dietary habits, health behavior and needs for contents and composition of the application. The mean age of the subjects was 31.9 years and the mean gestation period was 25.4 weeks. The rate of skipping meal was 39.0% and the rate of irregular meal time was 46.6%. The consciousness of the meal as balanced nutrition and health was 19.9%. Eating out at least forth a week was 35.3%. Obtaining information about pregnancy and childbirth were internet (35.3%), hospital or health center (19.9%), books (17.1%), experience (15.2%), mobile (8.6%) and friends or acquaintances (4.8%). If the application is developed, subject replied 'frequently use' (51.4%), 'when needed' (47.6%) respectively. The favour topic in developing application were 'nutrition information of pregnant and fetal' (36.2%), 'weight management, feeding' (33.3%), 'food choice and cooking' (21.9%), 'shopping' (5.7%), 'example of menu' (1.9%), 'effect of smoking, drinking, exercising' (1.0%). The favorite content was 'include sufficient amount about information' (44.8%). Depending on the age and education level, the best age for pregnancy group have significantly higher ability for utilize and information gathering than old age pregnant group. Also the best age for pregnancy group have high demands of design, convenience and various contents in App development. Therefore, mobile application (App) for pregnant women could be widely used as an effective dietary guide.