• Asian Pacific Journal of Cancer Prevention
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• 제15권22호
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• pp.9731-9737
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• 2014

Large scale secular registry or surveillance systems have been accumulating vast data that allow mathematical modeling of cancer incidence and mortality rates. Most contemporary models in this regard use time series and APC (age-period-cohort) methods and focus primarily on predicting or analyzing cancer epidemiology with little attention being paid to implications for designing cancer registry, surveillance or evaluation initiatives. This research models age-specific cancer incidence rates using logistic growth equations and explores their performance under different scenarios of data completeness in the hope of deriving clues for reshaping relevant data collection. The study used China Cancer Registry Report 2012 as the data source. It employed 3-parameter logistic growth equations and modeled the age-specific incidence rates of all and the top 10 cancers presented in the registry report. The study performed 3 types of modeling, namely full age-span by fitting, multiple 5-year-segment fitting and single-segment fitting. Measurement of model performance adopted adjusted goodness of fit that combines sum of squred residuals and relative errors. Both model simulation and performance evalation utilized self-developed algorithms programed using C# languade and MS Visual Studio 2008. For models built upon full age-span data, predicted age-specific cancer incidence rates fitted very well with observed values for most (except cervical and breast) cancers with estimated goodness of fit (Rs) being over 0.96. When a given cancer is concerned, the R valuae of the logistic growth model derived using observed data from urban residents was greater than or at least equal to that of the same model built on data from rural people. For models based on multiple-5-year-segment data, the Rs remained fairly high (over 0.89) until 3-fourths of the data segments were excluded. For models using a fixed length single-segment of observed data, the older the age covered by the corresponding data segment, the higher the resulting Rs. Logistic growth models describe age-specific incidence rates perfectly for most cancers and may be used to inform data collection for purposes of monitoring and analyzing cancer epidemic. Helped by appropriate logistic growth equations, the work vomume of contemporary data collection, e.g., cancer registry and surveilance systems, may be reduced substantially.

• Nuclear Engineering and Technology
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• 제53권10호
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• pp.3236-3246
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• 2021

Lessons learned from the Fukushima Daiichi nuclear power plant accident directed that multiple failures should be considered more seriously rather than single failure in the licensing bases and safety cases because attempts to take accident management measures could be unsuccessful under the high radiation environment aggravated by multiple failures, such as complete loss of electric power, uncontrollable loss of coolant inventory, failure of essential safety function recovery. In the case of the complete loss of electric power called station blackout (SBO), if there is no mitigation action for recovering safety functions, the reactor core would be overheated, and severe fuel damage could be anticipated due to the failure of the active heat sink. In such a transient condition at CANDU-6 plants, the seal failure of the primary heat transport (PHT) pumps can facilitate a consequent increase in the fuel sheath temperature and eventually lead to degradation of the fuel integrity. Therefore, it is necessary to specify the regulatory guidelines for multiple failures on a licensing basis so that licensees should prepare the accident management measures to prevent or mitigate accident conditions. In order to explore the efficiency of implementing accident management strategies for CANDU-6 plants, this study proposed a realistic accident analysis approach on the SBO transient with multiple-failure sequences such as seal failure of PHT pumps without operator's recovery actions. In this regard, a comparative study for two PHT pump seal failure modes with and without coolant seal leakage was conducted using a best-estimate code to precisely investigate the behaviors of thermal-hydraulic parameters during transient conditions. Moreover, a sensitivity analysis for different PHT pump seal leakage rates was also carried out to examine the effect of leakage rate on the system responses. This study is expected to provide the technical bases to the accident management strategy for unmitigated transient conditions with multiple failures.

• 한국수정란이식학회지
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• 제6권1호
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• pp.13-24
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• 1991

The objective of this experiment was to study some possibilities to simplify freezing, thawing and transfer procedure of one-step straw method comparing with the conventional methods using bovine embryos. The previous work are also designed to investigate the thawing effect by development stage and its quality using the embryos. Results obtained were summarized as follows: 1. A total of 87 embryos from 14 donor cows were frozen-thawed and an average of frozen embryo/donor was 6.2. 2. The survival rates of morula stage(65.4%) were higher than those of blastocyst stage(57.l%) and vice versa in rate of morphological recovery (80% vs 95.4%). However. no significant difference was denoted between them. 3. In difference between the groups of good quality and poor quality. good quality was resulted in a significantly higher embryo survival rate(75%) and recovery rates(95%) than poor quality(P<0.0l). 4. In effects of non-permeable sugar dilution in added to l.0M glycerol. higher survival rates were orderd in sucrose. lactose, raffinose and xylose. But lactose-raffinose, sucrose-trehalose and xylose in added to 2.OM glycerol. 5. The highest survival rates were obtained by direct plunge into the liquid nitrogen with 3.OM concentration both of glycerol and trehalose. 6. The survival rates in vitro condition of one-step and direct plunge methods(75%-87.5%) were significantly higher than those of multiple steps (21.4-52.6%) in in vitro (P<0.0l). However, the results of single-step were critical in comparing to other steps of final pregnant conformation.

• Journal of Preventive Medicine and Public Health
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• 제45권2호
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• pp.70-77
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• 2012

Objectives: Identify the characteristics related to the suicide rates in rural and urban areas of Korea and discover the factors that influence the suicide rate of the rural and urban areas. Methods: Using the data on causes of death from 2006 to 2008, the suicide rates were calculated and compared after age-standardization based on gender, age group and urbanicity. And, in order to understand the factors that influence suicide rate, total 10 local characteristics in four domains - public service, social integration, residential environment, and economic status - were selected for multiple regression analysis. Results: The suicide rates were higher in men than women, in rural areas than urban, and in older people than the younger. Generally, although there were variations according to age group and urbanicity, suicide rates were significantly related to residential environment and regional economic status but not related to regional welfare spending and social integration. In addition, the population over the age of 65 years, only regional economic status has significantly influence on their suicide rates. Conclusions: The influence of characteristics of regions on suicide rate is various by age-group, gender, and urbanicity. Therefore, in order to lower suicide rate and reduce the gap between regions, various approaches must be adopted by taking into account the socioeconomic characteristics of the regions.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제17권1호
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• pp.1-16
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• 2014

본 연구는 유추 거리 및 수학적 지식과 학습의 전이 사이의 관계를 규명하기 위해 수행되었다. 구체적으로 유추적 거리에 따라 구분된 세 가지 전이 문제 해결에서 차이를 보이는지, 그리고 각 전이 문제를 성공적으로 해결하는데 기여하는 수학적 지식은 무엇인지를 분석하였다. 분석 결과 세 가지 종류의 전이 문제 해결에서 통계적으로 유의한 차이를 보였으며 유추 거리가 증가할수록 성공률은 점차적으로 감소하였다. 또한 사실 지식 보다는 개념적 지식이 전이 문제를 해결하는데 긍정적으로 기여하였다. 이상의 결과를 토대로 본 연구는 학습의 전이를 위해 수학 수업은 어떠한 점에 초점을 맞추어야 하는지, 그리고 유추 거리라는 새로운 구인을 찾고 그것이 전이에 미치는 영향을 실증적으로 규명했다는 점에서 의의를 찾을 수 있었다.

• Journal of Preventive Medicine and Public Health
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• 제45권4호
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• pp.211-218
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• 2012

Objectives: The objective of this study was to identify the differences in obesity rates among people with and without disabilities, and evaluate the relationship between obesity rates and the existence of disabilities or characteristics of disabilities. Methods: Mass screening data from 2008 from the National Disability Registry and National Health Insurance (NHI) are used. For analysis, we classified physical disability into three subtypes: upper limb disability, lower limb disability, and spinal cord injury. For a control group, we extracted people without disabilities by each subtype. To adjust for the participation rate in the NHI mass screening, we calculated and adopted the weight stratified by sex, age, and grade of disability. Differences in obesity rates between people with and without disabilities were examined by a chi-squared test. In addition, the effect of the existence of disabilities and grade of disabilities on obesity was examined by multiple logistic regression analysis. Results: People with disabilities were found to have a higher obesity rate than those without disabilities. The obesity rates were 35.2% and 35.0% (people with disabilities vs. without disabilities) in the upper limb disability, 44.5% and 34.8% in the lower limb disability, 43.4% and 34.6% in the spinal cord injury. The odds for existence of physical disability and grade of disability are higher than the nondisabilities. Conclusions: These results show that people with physical disability have a higher vulnerability to obesity.

• 한국정보통신학회논문지
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• 제12권12호
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• pp.2195-2200
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• 2008

WLAN 기술의 사용은 적은 비용과 손쉬운 WLAN 장비 설치로 인하여 짧은 기간 동안 많은 성장이 있었다. 이러한 기술들은 물리적 계층에서 사용하는 변조에 따라서 1Mbps에서 54Mbps까지 다양한 데이터 전송률을 제공하여 준다. 본 논문에서는 네트워크 시뮬레이터인 OPNET을 활용하여 802.11b와 g에서 모바일 IPv4환경에서 데이터 전송률에 따른 효율과 다른 ESS의 AP사이에서 WLAN station 로밍에 의한 데이터 트래픽 수신에 대한 효율을 분석하였다. 실험결과, 모바일 에이전트에서 핸드오버를 하는 동안 많은 데이터 손실이 있다는 것을 알 수 있었다. 두 가지 WLAN 기술에서 제공해주는 데이터 전송률 기반에 의한 로밍 스테이션의 변화에 의해 트래픽은 수신하였다.

• 아태비즈니스연구
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• 제12권2호
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• pp.115-129
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• 2021

Purpose - This study aimed to clarify the effects of tax investigation probability on accounting transparency in KOSDAQ firms by using financial statement. In particular, it was analyzed whether the characteristics of a firm's listed market have a discriminatory effect on the relationship between the tax investigation selection rate (or detection rate) and earnings management. Design/methodology/approach - This paper examines analyzed the effect of tax investigation of the National Tax Service on the earnings management. The sample includes 9,603 firms listed on KOSPI and KOSDAQ from 2011 to 2018, all of which are manufacturing firms. This study conducted correlation and multiple regression analyses to verify the relationship between tax investigation probability and earnings management. The possibility of a tax investigation is the selection rate and the detection rate, and the profit adjustment was estimated at discretionary amount. Findings - As a result of empirical analysis, both firms listed on KOSPI and KOSDAQ markets showed that the higher the tax investigation rates, the more significant the possibility of reducing the earnings management of discretionary accruals. Additionally it was found that in KOSDAQ markets firms, the tax investigation detection rates had a signigicant nagative effect on discretionary accruals. Research implications or Originality - It can be interpreted that firms with a high rates of receiving a tax investigation decrease earnings management consideration of expenses such as additional tax amount due to the tax audit or a decline in corporate image.

• 보건의료산업학회지
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• 제11권4호
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• pp.89-104
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• 2017

Objectives : The purpose of this study was to find the determinants for non-participation in health screenings among the disabled. Methods : We used 2014-15 Korea Health Panel data and analyzed 1,073 people with disabilities older than 19 years to investigate the two-year health screening participation rates. Multiple logistic regression analyses were conducted to analyze the factors affecting non-participation in health screenings. Results : Of the 1,073 people with disabilities who were analyzed, 29.8% and 27.1% participated in NHI mass screenings and cancer screenings, respectively. In both screenings, non-participation rates were higher in people aged 19-49 and lower in people aged 50 -69 than those aged 70 or older; higher in people with lower education, higher in people with private health insurance; higher in people with fewer chronic diseases; and higher in people with severe disability ratings. Conclusions : People with disabilities should be provided with more appropriate preventive care services according to their disability types and severity compared to people without disabilities.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제19권1호
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• pp.79-86
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• 1997

Adenoid cystic carcinoma is characterized by sloe growth, multiple recurrence, a long clinical course and late metastasis. It is less than 1% of all head and neck malignancy, but most prevalent malignancy in salivary gland origin. During 14 years(from 1982 to 1995), 24 patients were diagnosed as adenoid cystic carcinoma in oral and maxillfacial area, in department of Oral and Maxillofacial Surgery, Korea Cancer Center Hospital. We studied clinically about their age and sex distribution, primary site distribution, TNM staging, treatment modalities, overall survival rates, survival rates according to stages. The age range were from 15 years to 79 years, average age weas 51 years. 15 were men and 9 Were women. Maxilla and palate were the most prevalent primary site. The most cases were in stage III(37%) and stage IV(46%). The 3 year and 5 year overall survival rate were 65.0% and 58.5%. The 5 year survival rate of the stage III cases was 66.7%, and that of the stage IV cases was 38.4%.