• Journal of the Korean Data Analysis Society
• /
• 제20권6호
• /
• pp.3069-3085
• /
• 2018

본 연구에서는 구직기간과 근속기간에 미치는 비인지적 요인의 영향을 살펴보았다. 한국노동연구원의 노동패널 18차 삶의 인식에 대한 부가조사자료에는 개인의 비인지적 특성을 묻는 질문 문항이 들어있다. 노동패널자료를 사용하여 big5 성격특성과 통제소재 변인에 대한 내적일치도를 살펴보고, 분석방법으로는 구직기간과 근속기간 등 절단(censored)이 있는 표본을 포함하고 있는 자료의 분석에 적합한 비례위험해저드모형을 사용하였다. 추정결과 성격특성과 통재소재 등 비인지적 요인이 개인의 노동시장 성과에 영향을 미치는 것을 확인하였다. 구직기간 분석에서 성격요인 중 성실성이 성인구직자의 구직기간을 길게 하여 실업탈출률을 낮추는 것으로 나타났다. 이는 실업과 같은 불확실한 상황에서는 성실성으로 표현되는 신중함이 구직에 필요한 정보해석을 잘못하거나 왜곡할 수 있고, 결단성의 결여로 실업탈출에 제약이 되는 것으로 보인다. 근속기간 분석에서는 내적통재 소재자의 경우 근속기간이 길어 직장이탈가능성이 낮았다. 내적통재소재자는 내가 열심히 하면 조직에서 성공과 승진이 가능하다고 믿는 경향이 강하기 때문에 조직에 의해 더 선호될 수 있으며, 내적통제 경향이 강할수록 스스로의 행동에 대한 동기부여와 자제심이 크기 때문에 한 직장에 오래 머물 수 있는 요인이 되는 것으로 보인다.

• 아태비즈니스연구
• /
• 제11권3호
• /
• pp.229-242
• /
• 2020

Purpose - To study the factors that are related with compliance for the voluntary surrender program of drive's license for senior drives and to estimate the rate of voluntary surrender. Design/methodology/approach - We online surveyed 147 individuals in order to analyze the intention to comply the program. The surveyees were driver's license holders aged 54 to 65 and drawn to answer their willingness to comply in a 5-point Likert scale. We developed an ordered probit model to analyze the data. Findings - According to the main results of the empirical analysis, the higher the average number of driving per week, regardless of gender and age, the more negative was the driver toward voluntarily surrender of driver's license. Various policy measures need to be prepared to activate the voluntary surrender system using the willingness to voluntarily surrender the driver's license and the characteristics of the voluntary returners, and the implementation of customized safe driving training for elderly drivers may be one such method. Research implications or originality - Population aging is known to cause various social problems, and in the transportation field, the number of elderly drivers and traffic accidents by elderly drivers are also increasing. The government is implementing a program for elderly drivers to voluntarily surrender of their driver's licenses in order to reduce traffic accidents caused by elderly drivers. If only elderly drivers who rarely drive surrender their driver's licenses then traffic accidents may not reduce as much as the program targets, however, and further policy instruments may be needed.

• 한국항만경제학회지
• /
• 제37권3호
• /
• pp.75-91
• /
• 2021

최근 제4차산업 혁명의 적용으로 물류비 절감을 위한 공급사슬 측면의 경쟁이 더욱 치열해지면서 항만전문가들은 효율적인 항만운영 비즈니스모델을 개발에 관심이 집중되어 있다. 본 연구는 세계 여러 항만 중 미국 항만 물류량이 많은 항만을 분석하여 적용 모델을 구성하고자 한다. 본 연구는 주로 미국 항만의 생산성을 연구하기 위해 DEA(Data Enclapment Analysis) 기법을 사용하였으며 미국 항만 운영의 성장 동력을 추가 조사하기 위해 Simar & Wilson(2007)이 제안한 이중 부트스트래핑 DEA 알고리즘을 적용했다. 본 연구에 사용된 외부 변수는 항만의 길이, 항만의 심도, 위치, 면적, 에이커, 외화 비율 및 TEUChange에 포함되며, 이 중 항만의 길이, 에이커, 외화 비율 및 TEUChange에 유의했다. 최적 방법론 선택의 효과를 평가하기 위해 관측 중단 모형(Tobit)을 적용하여 동일한 분석을 수행하고 서로 다른 두 기법에서 도출된 결과를 대조하였다. 본 연구에서 얻은 결과를 바탕으로 경영상의 시사점을 제안하고 결론을 도출하였다.

• 산업진흥연구
• /
• 제7권4호
• /
• pp.1-8
• /
• 2022

우리 주위를 살펴보면 한 번 사용하고 버리는 일회용품이 많다. 폭죽이나 탄약과 같은 일회용품이 대표적인데 이들 일회용품은 제조 후 한 동안 저장되어 있다가 필요한 때 사용하고 나면 폐기처분하게 된다. 하지만 이런 일회용품은 일반 운영장비와 달리 신뢰성평가가 제대로 이루어지지 못했다. 이에 본 연구에서는 일회용품 중에서 탄약에 대한 저장탄약신뢰성프로그램을 통해 탄약의 경우 신뢰성 확보를 위해 정부에서 어떤 일을 하는지 먼저 살펴본다. 이어서 통계분석적인 측면에서 탄약과 같은 일회용품에 대한 신뢰성분석 방안으로 어떤 것이 있는지 알아본다. 구체적으로 통계학에서 로트의 품질수준을 파악하는 샘플링검사를 활용하여 일정한 시기에 생산된 탄약에 대한 신뢰성의 수준을 파악할 수 있다. 본 연구에서는 KS Q0001인 계수규준형 1회 샘플링검사표를 이용할 수 있음으로 보여준다. 다음으로 탄약의 저장신뢰도를 파악할 수 있는 방법으로 비모수적인 방법과 모수적인 방법을 소개한다. 비모수적인 방법중에서 특히 Kaplan-Meier 방법은 중도중단데이터가 포함된 경우에도 활용될 수 있다. 마지막으로 모수적인 방법 중에는 신뢰성분석에 많이 활용되는 와이블분포가 탄약의 저장신뢰도를 파악하는 데에도 활용될 수 있다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권11호
• /
• pp.5643-5646
• /
• 2012

Background and Objectives: Increase of mortality rates of gastric cancer in Iran and the world in recent years reveal necessity of studies on this disease. Here, hazard function for gastric cancer patients was estimated using Wavelet and Kernel methods and some related factors were assessed. Materials and Methods: Ninety-five gastric cancer patients in Fayazbakhsh Hospital between 1996 and 2003 were studied. The effects of age of patients, gender, stage of disease and treatment method on patient's lifetime were assessed. For data analyses, survival analyses using Wavelet method and Log-rank test in R software were used. Results: Nearly 25.3% of patients were female. Fourteen percent had surgery treatment and the rest had treatment without surgery. Three fourths died and the rest were censored. Almost 9.5% of patients were in early stages of the disease, 53.7% in locally advance stage and 36.8% in metastatic stage. Hazard function estimation with the wavelet method showed significant difference for stages of disease (P<0.001) and did not reveal any significant difference for age, gender and treatment method. Conclusion: Only stage of disease had effects on hazard and most patients were diagnosed in late stages of disease, which is possibly one of the most reasons for high hazard rate and low survival. Therefore, it seems to be necessary a public education about symptoms of disease by media and regular tests and screening for early diagnosis.

• 가족자원경영과 정책
• /
• 제15권1호
• /
• pp.1-28
• /
• 2011

The purpose of this study is to analyze the family's meals of the daily time use and to examine how shared meals time together with family is influenced by socio-demographic variables. The Time Use Survey data collected by Korean National Statistical Office in 2009 is used. Among the total sample of 21,000 individuals, 9,179 samples who are married, aged from 20 to 59 years old and non-farmers are selected for analysis. The statistical methods are frequency, percentage, and censored regression model. The following is a summary of the major findings. The first, compared with the research results in 1999 and 2004, the time use of meals by adults is longer. But average time of family meals decreases and rates of family meals participants 2009 decrease 5.6% than 1999. Secondly, the family meals time increases from about 36 minutes on weekdays to about an hours at weekends. Regardless of the day, the women's family meals time is longer than that of men's. Thirdly, the influencing factors on family meals are sex, age, education, presence or absence of spouses, monthly income, weekly working hours and presence or absence of preschoolers. And the magnitude of gender differences in daily shared meals is not particularly large except in the case of some socio-demographic variables. Regardless of the day, women's family meals time is more affected by either dual-earner status or monthly income than that of men's.

• Asian Pacific Journal of Cancer Prevention
• /
• 제17권4호
• /
• pp.1729-1732
• /
• 2016

In the patients with metastatic colorectal cancer (mCRC), RAS testing is the first step to identify those that could benefit from anti-EGFR therapy. This study examined associations between KRAS mutations and clinicopathological and survival data in Iranian patients with mCRC. Between 2008 to2015 in a retrospective study, 83 cases of mCRC were referred to the Clinic of Medical Oncology. The mean follow-up was 45 months that there were 27 deaths. The 3 patients that did not complete follow-up were censored from the study. KRAS and NRAS were analyzed using allele-specific PCR primers and pyrosequencing in exons 2, 3 and 4. Multivariate survival analysis using Cox's regression model was used for affecting of variables on overall survival (OS). The mean age at diagnosis for patients was 57.7 (range, 18 to 80 years) and 61.4% were male. There was no significant different between prognostic factors and KRAS mutation with wild-type. Also, There was no significant different between KRAS mutation and KRAS wild-type for survival, but there was a significant different between KRAS 12 and 13 mutations for survival (HR 0.13, 95% CI 0.03-0.66, P=0.01). In conclusion, the prevalence of KRAS mutations in CRC patients was below 50% but higher than in other studies in Iran. As in many studies, patients with KRAS 12 mutations had better OS thn those with KRAS 13 mutation. In addition to KRAS testing, other biomarkers are needed to determine the best treatment for patients with mCRC.

• 한국산림과학회지
• /
• 제88권3호
• /
• pp.400-407
• /
• 1999

본 연구에서는 가치평가를 위한 설문내용은 일치하지만 상이한 질문형에 따라 평가된 휴양가치의 차이가 나타나는 지를 밝히는 데 목적을 두였다. 자료 수집을 위해 속리산 국립공원 방문객을 대상으로 폐쇄형인 양분선택 방식과 개방형인 직접지불 방식, 두 가지 질문형에 대해 동일한 피설문자에게 설문조사를 실시하였다. 이 때 얻고자 하는 방문객의 휴양가치는 동등변이에 기초한 최대지불의사액이었다. 분석에서 사용된 독립변수는 여행비용과 월 개인소득이다. 가치평가를 위한 기본모형은 단순선형을 가정하였으며 폐쇄형은 프로빗, 개방형은 토빗모형에 근거한 이변량정규분포모형을 사용하였다. 분석 결과, 응답자가 동일한 경우에 산출된 지불의사액은 질문형에 따라 차이가 없는 것으로 나타났으며 성인 방문객 1인의 5년간 속리산 국립공원에 대한 휴양가치는 25,556원으로 산출되었다.

• Journal of Communications and Networks
• /
• 제15권1호
• /
• pp.77-86
• /
• 2013

Cognitive radio (CR) has emerged as one of effective methods to enhance the utilization of existing radio spectrum. Main principle of CR is that secondary users (SUs) are allowed to use the spectrum unused by primary users (PUs) without interfering PU's transmissions. In this paper, PUs operate on a slot-by-slot basis and SUs try to exploit the slots unused by PUs. We propose OSA protocols in the single channel and we propose an opportunistic spectrum access (OSA) protocols in the multi-channel cognitive radio networks with one control channel and several licensed channels where a slot is divided into contention phase and transmission phase. A slot is divided into reporting phase, contention phase and transmission phase. The reporting phase plays a role of finding idle channels unused by PUs and the contention phase plays a role of selecting a SU who will send packets in the data transmission phase. One SU is selected by carrier sense multiple access / collision avoidance (CSMA/CA) with request to send / clear to send (RTS/CTS) mechanism on control channel and the SU is allowed to occupy all remaining part of all idle channels during the current slot. For mathematical analysis, first we deal with the single-channel case and we model the proposed OSA media access control (MAC) protocol by three-dimensional discrete time Markov chain (DTMC) whose one-step transition probability matrix has a special structure so as to apply the censored Markov chain method to obtain the steady state distribution.We obtain the throughput and the distribution of access delay. Next we deal with the multi-channel case and obtain the throughput and the distribution of access delay by using results of single-channel case. In numerical results, our mathematical analysis is verified by simulations and we give numerical results on throughput and access delay of the proposed MAC protocol. Finally, we find the maximum allowable number of SUs satisfying the requirements on throughput and access delay.

• 한국산업보건학회지
• /
• 제11권2호
• /
• pp.126-134
• /
• 2001

Statistical approaches for analysis of data from the limited number of samples in ship building industry(SBI) collected by an industrial hygienist for checking compliance to an occupational standard were considered. Sampling for compliance usually has been guided by judgment selection, rather than true randomness, resulting in the creation of compliance samples which approximate a censored sample from the upper tail of the exposure distribution. Similar exposure groups(SEGs) including welding and painting process were established to assess representative values in each groups after reviewing the whole production line in SBI. For the convenient statistical approaches, the code has assigned to each SEGs. The descriptive statistics and probability plotting were used to yield the representative values in each SEGs. In the first step, SEGs of 558 were established from 5 ship building companies. The 38 SEGs showed the uncertainty are divided into each 5 companies and assessed the representative values again. The 44 SEGs in each companies was not showed the normal and lognormal distribution was analyzed each data. And also, recommendation was suggested to resolve the uncertainty in each groups.