• 대한산업공학회지
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• 제33권1호
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• pp.52-60
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• 2007

Estimating parameters of the lifetime distribution is investigated when field failure data are not completelyreported. To take into account the reality and the accuracy of the estimates in such a case, the failure reportingprobability is incorporated in estimating parameters, Firstly, method of maximum likelihood estimate (MLE) isused to estimate parameters of the lifetime distribution when failure reporting probability is known, Secondly,Expectation and Maximization (EM) algorithm is used to estimate the failure reporting probability and parame-ters of the lifetime distribution simultaneously when failure reporting probability is unknown. For both cases,procedures of estimation are illustrated for single Weibull distribution and mixed Weibull distribution. Simula-tion results show that MLE obtained by the proposed method is more accurate than the conventional MLE.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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• pp.678-685
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• 2005

Estimating parameters of the lifetime distribution is investigated when field failure data are not completely reported. To take into account the reality and the accuracy of the estimates in such a case, the failure reporting probability is incorporated in estimating parameters. Firstly, method of maximum likelihood estimate(MLE) is used to estimate parameters of the lifetime distribution when failure reporting probability is known. Secondly, Expectation and Maximization(EM) algorithm is used to estimate the failure reporting probability and parameters of the lifetime distribution simultaneously when failure reporting probability is unknown. For both case, procedures of estimation are illustrated for single Weibull distribution and mixed Weibull distribution. Simulation results show that MLE obtained by the proposed method is more accurate than the conventional MLE.

• 경영과정보연구
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• 제33권1호
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• pp.173-190
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• 2014

COSO(2013)보고서에 따르면 내부통제제도는 운영목적과 보고목적 및 준수목적, 세 가지 각 측면에서 기업의 목적을 달성에 대한 합리적인 확신을 제공하기 위해 설계된 절차이다. 내부회계관리제도는 이러한 세가지 통제목적 중 보고목적에 초점을 두고 있으며 자산보호 및 부정방지 프로그램을 포함한다. 따라서 취약한 내부회계관리제도를 가진 기업은 자산의 유용이나 횡령과 같은 부정이 발생할 가능성이 증가할 뿐만 아니라 부정이나 오류가 포함된 회계정보를 산출함으로써 경영자의 의사결정을 오도할 가능성이 증가하므로 기업가치에 악영향을 미칠 수 있다. 이와 관련하여 본 연구는 내부회계관리제도가 기업실패 가능성에 영향을 분석하였다. 내부회계관리제도의 특성은 내부회계관리제도의 중요한 취약점 존재여부와 운영인력 특성으로 측정하고 기업실패 가능성은 감사보고서에 기재된 계속기업불확실성으로 정의하였다. 분석결과, 기업실패 가능성은 내부회계관리제도의 취약점 존재여부와 양(+)의 관련성을 발견하였고 내부회계관리제도 운영인력의 경력및 공인회계사 자격여부와는 음(-)의 관련성을 발견하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제46권4호
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• pp.220-227
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• 2020

Objectives: Papillon-Lefèvre syndrome (PLS) is a rare autosomal recessive disorder. These patients lose their teeth at a young age and are in need of prosthetic rehabilitation. The aim of this systematic review was to assess the success of dental implant placement in these patients. Materials and Methods: An electronic search was performed in PubMed Central, Scopus, and Web of Science using the keyword "Papillon-Lefèvre syndrome" AND "dental implant" OR "prosthodontics". Articles reporting implant placement in patients with PLS until July 2019 were included. Results: Assessment of the included 11 articles reporting 15 cases showed 136 implant placements in these patients. Implant failure occurred in 3 patients (20 implants). The peri-implantitis and failure rate was higher in the maxilla. Meta-analysis showed the probability of failure to be 7% (95% confidence interval [CI] 0%-31%) for maxillary implants and 2% (95% CI 0%-9%) for mandibular implants. The follow-up time ranged between 1 and 20 years. Healing after bone graft and implant placement in these patients was uneventful. Conclusion: Dental implants may be a viable treatment option for PLS patients. Implantation can help preserve alveolar bone if the patients' immunological and growing conditions are well-considered and proper oral hygiene and compliance with the maintenance program are continued.