• Communications for Statistical Applications and Methods
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• v.22 no.1
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• pp.95-103
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• 2015

We introduce a surplus process which follows a diffusion process with positive drift and is subject to two types of claim. We assume that type I claim occurs more frequently, however, its size is stochastically smaller than type II claim. We obtain the ruin probability that the level of the surplus becomes negative, and then, decompose the ruin probability into three parts, two ruin probabilities caused by each type of claim and the probability that the level of the surplus becomes negative naturally due to the diffusion process. Finally, we illustrate a numerical example, when the sizes of both types of claim are exponentially distributed, to compare the impacts of two types of claim on the ruin probability of the surplus along with that of the diffusion process.

• Journal of the Korean Operations Research and Management Science Society
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• v.15 no.1
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• pp.83-97
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• 1990

We consider an insured who wishes to determine his optimal reporting strategy over a given planning horizon, when he has option of reporting of not reporting his at-fault accidents. Assuming that the premium in future period is continually adjusted by the insured's loss experience, the insured would not report every loss incurred. Rather, considering the benefits and costs of each decision, the insured may want to seek a way of optimizing his interests over the planning horizon. The situation is modeled as a dynamic programming problem. We consider an insured's discounted expected cost minimization problem, where the premium increase in future period is affected by the size of the current claim. More specifically, we examine two cases ; (1) the premium increase in the next is a linear function (a constant fraction) of the current claim size; (2) the premium increase in the next period is a concave function of the current claim size. In each case, we derive the insured's optimal reporting strategy.

• Korean Journal of Radiology
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• v.24 no.12
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• pp.1179-1189
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• 2023

Objective: We aimed to evaluate the reporting quality of research articles that applied deep learning to medical imaging. Using the Checklist for Artificial Intelligence in Medical Imaging (CLAIM) guidelines and a journal with prominence in Asia as a sample, we intended to provide an insight into reporting quality in the Asian region and establish a journal-specific audit. Materials and Methods: A total of 38 articles published in the Korean Journal of Radiology between June 2018 and January 2023 were analyzed. The analysis included calculating the percentage of studies that adhered to each CLAIM item and identifying items that were met by ≤ 50% of the studies. The article review was initially conducted independently by two reviewers, and the consensus results were used for the final analysis. We also compared adherence rates to CLAIM before and after December 2020. Results: Of the 42 items in the CLAIM guidelines, 12 items (29%) were satisfied by ≤ 50% of the included articles. None of the studies reported handling missing data (item #13). Only one study respectively presented the use of de-identification methods (#12), intended sample size (#19), robustness or sensitivity analysis (#30), and full study protocol (#41). Of the studies, 35% reported the selection of data subsets (#10), 40% reported registration information (#40), and 50% measured inter and intrarater variability (#18). No significant changes were observed in the rates of adherence to these 12 items before and after December 2020. Conclusion: The reporting quality of artificial intelligence studies according to CLAIM guidelines, in our study sample, showed room for improvement. We recommend that the authors and reviewers have a solid understanding of the relevant reporting guidelines and ensure that the essential elements are adequately reported when writing and reviewing the manuscripts for publication.

• Journal of the Korean Operations Research and Management Science Society
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• v.40 no.3
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• pp.39-48
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• 2015

Even though ruin probability is a fundamental value to determine the insurance premium and policy, the complexity involved in computing its exact value forced us resort to an approximate method. In this paper, we first present an exact method to compute ruin probability under the assumption that the claim size has a GPH distribution, Then, for the arbitrary claim size distribution, we provide a method computing ruin probability quite accurately by approximating the distribution as a GPH. The validity of the proposed method demonstrated by a numerical example. The GPH approach seems to be valid for heavy-tailed claims as well as usual light-tailed claims.

• Korea Trade Review
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• v.41 no.3
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• pp.135-156
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• 2016

This study, with reference to data on economic conditions in Shandong Province, China, looked into trade and investment activities in Korea and major cities of Shandong - Qingdao, Yantai, Weihai and Jinan - and investigated claim cases between the two countries by type. In addition, we investigated the matter empirically by conducting a survey administered to 300 Korean companies investing in Shandong Province and, based on the data, tested hypotheses for inferential analysis. The findings are as follows: i) while hypotheses in which the size of a firm, represented by import and export volume, has a positive relation with the frequency of trade claim filings (H1) and with the financial value of the trade claims (H2) were quoted, company size proved to have a significantly negative relation with the time required to obtain a claim decision, which rejects the third hypothesis (H3) in which the relation was thought to be positive: ii) while products, as represented by the type of business, showed a clearly significant difference with the frequency of trade claim filings (H4) and with methods of preventing and responding to claims (H6), they did not show a significant link to the type of trade claim (H5). This study is a theoretical and empirical overview of Korean companies based in Shandong Province of China, and can be used to address the practical needs of the Korean companies looking to start business in Shandong Province.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.76
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• pp.125-145
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• 2017

Where an insurer has unreasonably refused to pay a claim or paid it after unreasonably delay, the existing law in England does not provide a remedy for the insured. Accordingly, the insured is not entitled to damages for any loss suffered as a result of the insurer's unreasonable delay. This legal position differs from the law in Scotland and most major common law jurisdictions. LC thought that the legal position in England is anomalous and out of step with general contractual principles. LC considered that a policyholder should have a remedy where an insurer has acted unreasonably in delaying or refusing payment of claim, and, therefore, recommended a statutory implied term in every insurance that the insurer will pay sums due within a reasonable time and breach of that term should give rise to contractual remedies, including damages. More detailed recommendations of LC are as followings. First, it should be an implied term of every insurance contract that, where an insured makes a claim under the contract, the insurer must pay sums due within a reasonable time. Secondly, a reasonable time should always include a reasonable time for investigating and assessing a claim. Although a reasonable time will depend on all the relevant circumstances, for example, the following things may need to be taken into account, that is, (1) the type of insurance, (2) the size and complexity of the claim, (3) compliance with any relevant statutory rules or guidance, and (4) factors outside the insurer's control. Thirdly, if the insurer can show that it had reasonable grounds for disputing the claim(whether as to pay or not, or the amount payable), the insurer does not breach the obligation to pay within a reasonable time merely by failing to pay the claim while the dispute is continuing. In those circumstances, the conduct of the insurer in handling the dispute may be a relevant factor in deciding whether the obligation was breached and, if so, when. Fourthly, Normal contractual remedies for breach of contract should be available for breach of the implied term to pay sums due within a reasonable time. Finally, In non-consumer insurance contracts, the insurer should be permitted to exclude or limit its liability for breach of the obligation to pay sums due within a reasonable time, unless such breach was deliberate or reckless, and such an insurer's right to contract out will be subject to satisfying the transparency requirements.

• The Korean Journal of Applied Statistics
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• v.34 no.5
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• pp.697-710
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• 2021

Relative error prediction is preferred over ordinary prediction methods when relative/percentile errors are regarded as important, especially in econometrics, software engineering and government official statistics. The relative error prediction techniques have been developed in linear/nonlinear regression, nonparametric regression using kernel regression smoother, and stationary time series models. However, random effect models have not been used in relative error prediction. The purpose of this article is to extend relative error prediction to some of generalized linear mixed model (GLMM) with panel data, which is the random effect models based on gamma, lognormal, or inverse gaussian distribution. For better understanding, the real auto insurance data is used to predict the claim size, and the best predictor and the best relative error predictor are comparatively illustrated.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.192-194
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• 2015

The growing size and complex process in construction project recently leads to increase risk and the losses as well. Even though researchers have identified the major risk indicators, there is lack of comprehensive and quantitative research for identifying the relationship between the risk indicators and economic losses associated with construction projects. To address this shortage of research, this study defines risk indicators and create a framework to assess the influence of economic losses from the indicators. An insurance company's claim payout record was accepted as the dependent variable to reflect the real economic losses. Based on the claims, we categorized the causes and results of accidents. To establish framework, built environment vulnerability indicators and geographical vulnerability indicators were employed as the risk indicators. A Pearson correlation analysis was adopted to validate the relationship with loss ratio and risk indicators. Consequently, this framework and its results may offer significant references for under writers of insurance companies and loss prevention activities.

• Bulletin of the Korean Mathematical Society
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• v.50 no.2
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• pp.611-626
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• 2013

In the paper we study the finite-time ruin probability in a general risk model with constant interest force, in which the claim sizes are pairwise quasi-asymptotically independent and arrive according to an arbitrary counting process, and the premium process is a general stochastic process. For the case that the claim-size distribution belongs to the consistent variation class, we obtain an asymptotic formula for the finite-time ruin probability, which holds uniformly for all time horizons varying in a relevant infinite interval. The obtained result also includes an asymptotic formula for the infinite-time ruin probability.

• Journal of applied mathematics & informatics
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• v.27 no.5_6
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• pp.1033-1047
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• 2009

In this paper, we consider a m-type risk model with Markov-modulated premium rate. A integral equation for the conditional ruin probability is obtained. A recursive inequality for the ruin probability with the stationary initial distribution and the upper bound for the ruin probability with no initial reserve are given. A system of Laplace transforms of non-ruin probabilities, given the initial environment state, is established from a system of integro-differential equations. In the two-state model, explicit formulas for non-ruin probabilities are obtained when the initial reserve is zero or when both claim size distributions belong to the $K_n$-family, n $\in$ $N^+$ One example is given with claim sizes that have exponential distributions.