• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.938-943
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• 2003

The characteristics of lightweight cellular concrete has much influence on the compressive strength and flow from the design of mixture. This study is to investigate the characteristics of the compressive strength and flow for the mixture of lightweight cellular slurry. KS F 4039 was compared to the construction system and quality for lightweight cellular comcrete of floating floor. As the result of this study, the standard of the compression strength for target slurry have to lower and an upper limit of flow was judged to be 230mm

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.21 no.1
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• pp.31-36
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• 2010

Objective ： We investigated the characteristics of cellular phone use and its association with psychological problems among adolescents. Methods ： A total of 332 adolescent students were recruited for this study. The participants' self-reported characteristics of cellular phone use and the psychological problems caused by this were tested by using the Excessive Cellular Phone Use Survey (ECPUS), the Children's Depression Inventory (CDI), Spielberger's State-Trait Anxiety Inventory for Children (STAIC) and the Korea-Youth Self Report (K-YSR). Results ： The excessive user group made more use of text messages and they spent more time and paid higher fees than the comparison group. They expressed severer depression and anxiety and they had more behavior problems and lower school performance than the comparison group. The ECPUS score was positively correlated with score of the CDI, STAIC and the behavior problem scales of the K-YSR, and the ECPUS score was negatively correlated with the school performance scale of the K-YSR. Conclusion ： Our findings suggest that excessive cellular phone use by adolescents may be related to psychological problems. Careful education about the use of cellular phones and intervention are recommended for adolescents who excessively use cellular phones.

• Research in Community and Public Health Nursing
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• v.17 no.4
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• pp.552-562
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• 2006

Purpose: This study was conducted to describe the state of middle school students' addicted use of a cellular phone and their psychosocial characteristics and to examine differences in psychosocial factors as impulsivity, stress, anxiety and classroom attitudes according to the level of addiction. Method: As the subjects of this study, 747 middle school students who use a cellular phone in B Metropolitan City were selected through stratified random sampling, and they were asked to answer a self-administered study questionnaire. Data were analyzed using frequency, descriptive statistics, $x^2-test$, t-test, and one-way ANOVA. Results Among the respondents, 15.7% fell into the addicted user group while 56.0% fell into the dependent user group and 28.3% turned out to be non-addicted users. The levels of impulsivity, stress and anxiety were higher in the addicted user group than in the dependent user group and the non-addicted user group. The addicted user group also showed a very bad learning attitude. Conclusion: Addiction to the use of a cellular phone, which may have negative influences on the users' psychosocial characteristics, needs to be detected earlier, and preventive education should be offered in order to prevent such addiction.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.147-148
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.145-146
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• 2008

• Journal of the Korean Home Economics Association
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• v.42 no.9
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• pp.135-147
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• 2004

The purposes of this study were to investigate the actual conditions and deal with the psychological characteristics of adolescent cellular phone addicts through the Minnesota Multiphase Personality Inventory (MMPI). The subjects of this study were 407 senior high school students (male 185, female 222) in 2nd grade in Daegu. The cellular phone addiction inventory (CPAI) was designed on the basis of an interview process, referring to the Young's Internet Addiction Self Diagnosis Scale. SPSS version 10.0 was employed for data analysis. The mean score of the adolescent addict group was significantly higher than the non-addict group in Scale Pd, Pa, Pt, Sc and Ma. This result indicates that the cellular phone addict group is likely to suffer from more serious pathological disorders than the non-addict group. The rate of addictive adolescents was significantly higher in the addict group than in the non-addict group in psychological problematic score ranges in Scale Sc (Schizophrenia) and Ma (Hypomania). The study result suggests that adolescents who addictively use a cellular phone will be more likely to show immaturity, instability, impulsive personality, excessive activities, and escapism.

• Elastomers and Composites
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• v.16 no.1
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• pp.3-13
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• 1981

The purpose of this dissertation is to study the physical properties of cellular rubber products for industrial use. Vulcanization characteristics were investigated by usingcure curve that had obtained by means of Rheometer. The results of physical properties, vulcanization characteristics and foaming states are as follows. 1. The test results for vulcanization characteristics of NR compounds indicated that in the recipe R-1. When accelerator D is used, the optimum conditions of vulcanizate are obtained, while formula R-2 and R-3 have shown higher torgue at curing time, $1{\sim}2$ minutes. Cellular rubber product test in terms of compression set and compression deflection has also met the requirements of SAE. 2. For SBR compounds, S-1 formula was the best in terns of vulcanization characteristics, and for the blowing structure of cellular rubber products, formula S-3 in which accelerator M is added was fair. All other test results, such as compression set and compression deflection properties met SAE requirements. 3. NBR compound (N-1) including accelerator TT was the best in terms of vulcanization characteristic and also blowing structure. All other properties listed above met requirements, particulary for oil resistance test. 4. In the test of EPDM compounds, when mixed accelerator, M and TT, is used(formula E-1) the best results were obtained. Since EPDM is hydrocarbon elastomer, oil resistance test failed. All other properties met the requirement specified in SAE.

• Journal of the Korean Home Economics Association
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• v.43 no.4 s.206
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• pp.1-16
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• 2005

This study investigated firstly the cellular phone addiction tendency according to the classification of addiction, dependency, non-addiction and predicting factors of cellular phone use and secondly the psycho-social characteristics of cellular phone use by adolescent'. Participants were 368 students of academic and occupational high schools in Seoul. A prediction model of cellular phone addiction tendency was developed and show떠 that there were significant effects of cellular phone use-time, use-motives, counseling experience, impulsiveness, and depression on cellular phone addiction.

• Korean Management Science Review
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• v.12 no.2
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• pp.165-188
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• 1995

The conversion processes from traditional job shops to cellular manufacturing systems can be viewed as an aggregation of cause-and-effect relationships among many strategic, managerial, and technical variables. Therefore, management needs to fully understand these interacting variables and possible relationships between the variables to successfully convert their plants to cellular manufacturing systems. The purpose of this study is to assist such management's needs in part. The objectives of this research are i) investigating contingency variables that may affect the conversion processes and outcomes to cellular manufacturing systems and ii) examining relationships between the variables and the conversion processes and outcomes. In this paper, particularly three categories of variables are examined: product, process routing, and process technology / facilities characteristics. Literature review and the mail survey method are used. The results are compared and synthesized with the findings of previous studies for useful discussions. Some previous arguments and propositions are empirically supported.

• Journal of Families and Better Life
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• v.24 no.5 s.83
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• pp.101-112
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• 2006

This study examined factors related to the motivation for the uses of cellular phones and the relationship between motivation for cellular phone use and parent-child communication among middle school students. A total of 223 questionnaires were submitted and analyzed. The characteristics of motive structure of the middle school students were found as recreation, time management, information-seeking, reassurance and fashion/showing off. Among those motivations, these middle school students examined here were found to use cellular phones in similar ways to how conventional telephone is used such as work/instrumental reasons and socializing/entertaining. The motivations showed a significant association with the level of parent-child communication. Information-seeking and time management motivation were positively related with an open communication level while fashion/showing off and recreation were negatively related with an open communication level.