• 한국축산식품학회지
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• 제33권2호
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• pp.149-154
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• 2013

Food hygiene practices must be maintained from farm to table in order to prevent contamination by microorganisms. This study was conducted to investigate consumer hygiene practices related to the refrigerator storage of meat, including a microbial analysis, monitoring of refrigerator temperatures and consumer surveys of female homeowners in the capital area of Korea. Home refrigerator temperatures were maintained above $5^{\circ}C$ in 26 (19.7%) of the 132 houses investigated. The percentage of the refrigerators with a total microbial count over $10^2\;CFU/100\;cm^2$ was 14.4%. No E. coli, Salmonella spp. or Listeria monocytogenes microbes were detected. However, Staphylococcus aureus was detected in 14 houses (10.6%). The only statistically significant difference in hygiene practices between the non-contamination group and contamination group was in the last time of refrigerator cleaning (p<0.01), as determined by the consumer survey. To improve food hygiene when using a refrigerator, raw materials must be packaged, meat should be stored only on a designated shelf, and cooked foods must be contained to prevent cross-contamination. The refrigerator should be cleaned regularly, at least once a month, and refrigerator thermometers should be monitored below $5^{\circ}C$ in order to keep food safe.

• 대한조선학회지
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• 제8권1호
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• pp.53-66
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• 1971

The effect of reinforced circular hole in a flat plate under general biaxial loading conditions is considered. The reinforcement is achieved by attaching a circular ring of uniform rectangular cross section along the boundary of the hole. This investigation includes a theoretical solution and an experimental conformation. In the theoretical analysis, Gurney's method is used to obtain a solution for the stress distribution and the solution is expressed in a general form, so that it can be applicable to the case of general biaxial loading and general values of Poisson's ratios. In the experimental work a systematic series of photoelastic models, as shown in Fig.5 and Table 1, were analyzed on polariscope. The experimental results were in good agreement with the theoretical ones, as shown in Fig.8 and 9. The conclusions derived are as follows: 1) The theoretical results, given in Eq. $(1){\sim}(5)$, are sufficient in accuracy for the engineering design purpose. 2) The stress concentration factor decreases as the ratio n increases, but not significant beyond n=3. 3) The stress concentration factor increase as the ratio m increases, but not significant below m=0.7.

• 교육시설 논문지
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• 제27권2호
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• pp.69-78
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• 2020

Interest in the school environment design is increasing as the project to restructure school space and to become common in school through smart devices. However, no research has been presented on the current status of studies on school environmental design, and the need for analysis of recent research trends in school environmental design is required. In response, this study aims to provide basic data on school environmental design by analysing the trends of domestic studies of school environmental design since 2010 and to present the direction of research on future school environmental design. A total of 312 papers related to school architecture and spatial design are set for study in the results of academic information search on school environmental design. Based on this, frequency analysis and cross-sectional analysis are conducted based on the classification table according to the year of issue, research subject, research purpose, and research method. The statistical significance of the research subjects was secured in accordance with the year of issue and subject to study, and accordingly the key research key words were derived. It is meaningful that through this study, the current status of school environmental design research over the last 10 years can be analyzed and the direction for the future school environmental design research has been suggested.

• 응용통계연구
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• 제26권4호
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• pp.675-686
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• 2013

현재 우리나라 식품의약품안전청에서는 $2{\times}2$ 교차설계법을 기초로 제제간의 생물학적 동등성 평가를 수행하도록 규정하고 있다. 하지만 고변동성 제제의 생물학적 동등성 평가에서 $2{\times}2$ 교차설계법에 의한 시험은 지나치게 많은 피험자를 필요로 할 수 있어 윤리적이고 경제적인 고려가 필요하다는 논의가 이루어지고 있다. $2{\times}2$ 교차설계법을 대체할 수 있는 대안으로 $2{\times}4$ 교차설계법은 미국 및 유럽 등에서는 생물학적 동등성 평가에 광범위하게 사용되는 설계 방법이고, $2{\times}3$ 교차설계법도 $2{\times}2$와 $2{\times}4$ 교차설계법의 단점을 개선할 수 있는 효율적인 대안으로 관심이 많다. 본 연구에서는 $2{\times}4$와 $2{\times}3$ 교차설계법의 통계적 모형과 제시된 통계적 모형에 연계된 분산분석표를 유도한다. 현행 국내 생물학적 동등성 시험 규정에 의하면 $2{\times}4$와 $2{\times}3$ 교차설계법의 분산분석표는 반드시 제시되어야 하지만 아직 문헌상에 존재하지 않아 관련 연구에 기여할 것으로 생각된다. 또한 $2{\times}4$와 $2{\times}3$ 교차설계법에 기초한 피험자 계산을 $2{\times}2$ 교차설계법과 비교 제시하여 고변동성 제제의 생물학적 동등성 시험 연구에 적절한 시험 설계 선택에 정보를 제공한다.

• 한국학교보건학회지
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• 제23권2호
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• pp.295-307
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• 2010

Purpose: This study was conducted to find ways to improve foodservice quality and satisfaction of middle school students in school lunch service. Recognition of concerns about school lunch and quality attributes was evaluated by gender. And we tried to investigate quality attributes which could affect degree of foodservice satisfaction by gender. Methods: Two hundred students from each of 6 middle schools (3 schools in urban and 3 schools in rural) in Gyeonggi Province were surveyed using self-developed questionnaires. Total of 1,103 questionnaires (male 556 and female 547) were collected and data were analyzed using descriptive analysis, t-test, cross table and stepwise multiple regression by SPSS 11.0. Results: There were not significant differences in average importance scores (male 4.09, female 4.06) and average performance scores (male 3.36, female 3.30) of quality attributes between middle school boys and girls. But there were significant differences in 7 and 6 of 25 quality attributes in evaluating importance and performance respectively by gender. There was not a significant difference (male 3.13, female 3.24) in degree of foodservice satisfaction by gender. But there were significant differences in the distribution of satisfaction. Stepwise multiple regression analysis showed that degree of satisfaction was influenced by a taste of food, quick complaint handling, providing favorite foods, and food hygiene in male students (F=$51.1^{***}$, adjusted $R^2$=.265). Degree of satisfaction was influenced by a taste of food, providing favorite food, proper meal prices, providing a wide variety of food in female students (F=$91.4^{***}$, adjusted $R^2$=.399). Conclusion: We found out that there were significant differences in quality attributes when evaluating importance and performance and in quality attributes which could affect foodservice satisfaction by gender.

• 복식문화연구
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• 제15권4호
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• pp.661-676
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• 2007

The purpose of this study was to investigate the periodical change of Korean children's clothing from 1960 to 2000. As valuable historical data, 794 children's clothing in wedding pictures in these periods were collected for this study. Research method was content analysis and frequency, cross table analysis, and ${\chi}^2$ test were conducted for data analysis. The results of this study were as follows. The children's clothing in 1960s had very humdrum and limited design and plain pattern. And most of children in this period wore Western clothes of casual style. In 1970s, children's clothing was enriched in terms of design, pattern, color and ornament. However, clothing design for children was not developed yet, so form of children's clothing in this period was showed as duplication of adult clothing design. In 1980s, The children's clothing was developed with enhancement of the level of living. Various style and sophisticated design were appeared and design and size system for children were developed. With increasement of social interest of leisure and sports, casual style was especially popular in this period for both of children and adult in this period. In 1990, rapid decrease of birth rate resulted in parents' excessive interest and investment for their children. In this effects, children's clothing in 1990s had luxury, various, and individual characteristics.

• 한국지형학회지
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• 제27권2호
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• pp.65-80
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• 2020

This paper deals with risk assessment of life in a landslide-prone area by a GIS-based modeling method. Landslide susceptibility maps can provide a probability of landslide prone areas to mitigate or proper control this problems and to take any development plan and disaster management. A landslide inventory map of the study area was prepared based on past historical information and aerial photography analysis. A total of 550 landslides have been counted at the whole study area. The extracted landslides were randomly selected and divided into two different groups, 50% of the landslides were used for model calibration and the other were used for validation purpose. Eleven causative factors (continuous and thematic) such as slope, aspect, curvature, topographic wetness index, elevation, forest type, forest crown density, geology, land-use, soil drainage, and soil texture were used in hazard analysis. The correlation between landslides and these factors, pixels were divided into several classes and frequency ratio was also extracted. Eventually, a landslide susceptibility map was constructed using a logistic regression model based on entire events. Moreover, the landslide susceptibility map was plotted with a receiver operating characteristic (ROC) curve and calculated the area under the curve (AUC) and tried to extract a success rate curve. Based on the results, logistic regression produced an 85.18% accuracy, so we believed that the model was reliable and acceptable for the landslide susceptibility analysis on the study area. In addition, for risk assessment, vulnerability scale were added for social thematic data layer. The study area predictive landslide affected pixels 2,000 and 5,000 were also calculated for making a probability table. In final calculation, the 2,000 predictive landslide affected pixels were assumed to run. The total population causalities were estimated as 7.75 person that was relatively close to the actual number published in Korean Annual Disaster Report, 2006.

• 비교문화연구
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• 제28권
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• pp.115-139
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• 2012

Interval or duration of segments, syllables, words and phrases is an important acoustic feature which influences the naturalness of speech. A number of cross-sectional studies regarding acoustic characteristics of children's speech development found that intervals of segments, syllables, words and phrases tend to change with the growing age. One hypothesis assumed that decreases in intervals would be greater when children were younger and smaller decreases in intervals when older (Thelen,1991), it has been supported by quite a number of researches on the basis of cross-sectional studies (Tingley & Allen,1975; Kent & Forner,1980; Chermak & Schneiderman, 1986), but the other hypothesis predicted that decreases in intervals would be smaller when children were younger and greater decreases in intervals when older (Smith, Kenney & Hussain, 1996). Researchers seem to come up with conflicting postulations and inconsistent results about the change trends concerning intervals of segments, syllables, words and phrases, leaving it as an issue unresolved. Most acoustic investigations of children's speech production have been conducted via cross-sectional designs, which involves studying several groups of children. So far, there are only a few longitudinal studies. This issue needs more longitudinal investigations; moreover, the acoustic measures of the intervals of child speech are hardly available. All former studies focus on word stages excluding the babbling stages especially the canonical babbling stage, but we need to find out when concrete changes of intervals begin to occur and what causes the changes. Therefore, we conducted an acoustic study of interval characteristics of segments and words concerning Canonical Babble ( CB) and early speech in an infant aged from 0;9 to 2;4 acquiring Mandarin Chinese. The current research addresses the following two questions: 1. Whether decreases in interval would be greater when children were younger and smaller when they were older or vice versa? 2. Whether the child speech concerning the acoustic features of interval drifts in the direction of the language they are exposed to? The female infant whose L1 was Southern Mandarin living in Changsha was audio- and video-taped at her home for about one hour almost on a weekly basis during her age range from 0;9 to 2;4 under natural observation by us investigators. The recordings were digitized. Parts of the digitized material were labeled. All the repetitions were excluded. The utterances were extracted from 44 sessions ranging from 30 minutes to one hour. The utterances were divided into segments as well as syllable-sized units. Age stages are 0;9-1;0,1;1-1;5, 1;6-2;0, 2;1-2;4. The subject was a monolingual normal child from parents with a good education. The infant was audio-and video-taped in her home almost every week. The data were digitized, segments and syllables from 44 sessions spanning the transition from babble to speech were transcribed in narrow IPA and coded for analysis. Babble was coded from age 0;9-1;0, and words were coded from 1;0 to 2;4, the data has been checked by two professionally trained persons who majored in phonetics. The present investigation is a longitudinal analysis of some temporal characteristics of the child speech during the age periods of 0;9-1;0, 1;1-1;5, 1;6-2;0, 2;1-2;4. The answer to Research Question 1 is that our results are in agreement with neither of the hypotheses. One hypothesis assumed that decreases in intervals would be greater when children were younger and smaller decreases in intervals when older (Thelen,1991); but the other hypothesis predicted that decreases in intervals would be smaller when children were younger and greater decreases in intervals when older (Smith, Kenney & Hussain, 1996). On the whole, there is a tendency of decrease in segmental and syllabic duration with the growing age, but the changes are not drastic and abrupt. For example, /a/ after /k/ in Table 1 has greater decrease during 1;1-1;5, while /a/ after /p/, /t/ and /w/ has greater decrease during 2;1-2;4. /ka/ has greater decrease during 1;1-1;5, while /ta/ and /na/ has greater decrease during 2;1-2;4.Across the age periods, interval change experiences lots of fluctuation all the time. The answer to Research Question 2 is yes. Babbling stage is a period in which the children's acoustic features of intervals of segments, syllables, words and phrases is shifted in the direction of the language to be learned, babbling and children's speech emergence is greatly influenced by ambient language. The phonetic changes in terms of duration would go on until as late as 10-12 years of age before reaching adult-like levels. Definitely, with the increase of exposure to ambient language, the variation would be less and less until they attain the adult-like competence. Via the analysis of the SPSS 15.0, the decrease of segmental and syllabic intervals across the four age periods proves to be of no significant difference (p>0.05). It means that the change of segmental and syllabic intervals is continuous. It reveals that the process of child speech development is gradual and cumulative.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권2호
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• pp.68-75
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• 2014

Objectives: This study was performed to analyze the cumulative survival rate of Osstem implants (Osstem Implant Co., Ltd.) over a seven-year period. Materials and Methods: A total of 105 patients who had 467 Osstem implants that were placed at the Section of Dentistry, Seoul National University Bundang Hospital (Seongnam, Korea) from June 2003 through December 2005 were analyzed. The life table method and a cross-tubulation analysis, log rank test were used to evaluate the survival curve and the influence that the prognostic factors. The prognostic factors, i.e., age and gender of patients, diameter and length, type of implants, bone graft history and loading time were determined with a Cox proportional hazard model based on logistic regression analysis. Results: The seven-year cumulative survival rate of Osstem implants was 95.37%. The Cox proportional hazard model revealed that the following factors had a significant influence on survival rate; increased diameter, reduced prosthetic loading period and performance of bone grafting. Conclusion: The osstem implants showed satisfactory results over the seven-year study period.

• 한국산업보건학회지
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• 제21권3호
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• pp.168-176
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• 2011

Objectives: Hundreds of thousands of call center workers are wearing an acoustic device for their businesses, such as telemarketing and customer counseling, and the number of the workers are increasing sharply. Because call center workers always talk to dozens of customers over the headset, they would be placed under the state of a higher risk with their hearing ability. The purpose of this study is to investigate factors that affect the hearing thresholds for the call center workers. Methods: This study investigated hearing losses of 101 workers of 5 call centers in Korea by executing puretone audiometry and self-administered questionnaires. A cross table analysis was processed to compare gender differences between male and female. Male and female hearing thresholds were compared with the Students' t-test, and one-way ANOVA was conducted to observe the difference between non-occupational and occupational characteristics in 2, 3, 4, 6, and 8 kHz hearing thresholds for the female workers. Additionally, multiple regression analysis was conducted to find the factors that affect the 4 kHz hearing thresholds. Results and Conclusions: Male hearing thresholds were higher than those of female except for 8 kHz. In the group having an ear related disease, hearing threshold of male left ear was highly affected rather than that of female in 4 kHz. There were significant differences in the variables of alcohol drinking (2 kHz) and headset volume (8 kHz) in both ears. While this study does not show any significant factors that affect the hearing thresholds in the occupational characteristics, the gender and the previous ear related diseases, non-occupational characteristics, were found as the factors in 4 kHz. It is suggested that the more detailed survey be performed to identify the occupational factors that affect the hearing thresholds in the call center workers based on the result derived from this study.