• Journal of Korean Society of Coastal and Ocean Engineers
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• v.35 no.4
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• pp.67-74
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• 2023

High waves and storm surges due to tropical cyclones cause great damage in coastal areas; therefore, accurately predicting storm surges and high waves before a typhoon strike is crucial. Meteorological forcing is an important factor for predicting these catastrophic events. This study presents an improved methodology for determining accurate meteorological forcing. Typhoon Chaba, which caused serious damage to the south coast of South Korea in 2016, was selected as a case study. In this study, symmetric and asymmetric parametric vortex models based on the typhoon track forecasted by the Model for Prediction Across Scales (MPAS) were used to create meteorological forcing and were compared with those models based on the best track. The meteorological fields were also created by blending the meteorological field from the symmetric / asymmetric parametric vortex models based on the MPAS-forecasted typhoon track and the meteorological field generated by the forecasting model (MPAS). This meteorological forcing data was then used given to two-way coupled tide-surge-wave models: Advanced CIRCulation (ADCIRC) and Simulating Waves Nearshore (SWAN). The modeled storm surges and waves correlated well with the observations and were comparable to those predicted using the best track. Based on our analysis, we propose using the parametric model with the MPAS-forecasted track, the meteorological field from the same forecasting model, and blending them to improve storm surge and wave prediction.

• Journal of Industrial Convergence
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• v.20 no.12
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• pp.59-70
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• 2022

This study investigates the sensitivity reflected in the accounting earnings differs according to the difference in the characteristics of accounting information such as profit and loss for the same market information. For this, market information and accounting data were analyzed for 11,462 non-financial listed companies listed on the KOSPI and KOSDAQ markets from 2012 to 2020 by using Basu's measurement of conditional conservatism and Ball and Shivakumar's measurement of conservatism. Accounting earnings sensitivity was analyzed according to the combination of information. As a result of the study, it was confirmed that both earnings and losses corporates recognize losses with delay, while losses are recognized quickly by loss corporates and delayed recognition by earnings companies. It was confirmed that more strict conservatism was applied to the losses corporates compared to the earnings corporates by delaying the recognition of earnings while the early recognition of the losses. It provides empirical data on the causality between the asymmetric timeliness and the combined effect of market information and accounting information by verifying that the losses corporates responds sensitively to market information while the earnings corporates does not react sensitively to the market information.

• Science of Emotion and Sensibility
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• v.4 no.2
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• pp.69-77
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• 2001

Positively biased asymmetry between positive and negative cognition is the basic assumption of heuristic human functioning. This article describes the SOM(states of mind) model for emotional judgement, a psycho-mathematical model built on affective-cognitive assessment research on the balance of positive and negative thoughts and feelings. The SOM model suggests that subjects on the average choose a positive over a negative pole with the probability 0.62 and the precise value of this constant coincides with algebraic “golden section” 　.618:.382. Statistical analyses of 32 normal subjects shows that the mean of SOM ratios of self-referent judgement and incidental recall task for positive/negative emotional words are .62(SD=.08) and .58(SD=.4). Also, the SOM ratios are significantly correlated with self-referent judgement for positive/negative emotional words. Implications of cognitive balance and future research directions for emotional science are discussed.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.5
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• pp.396-403
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• 2009

An anonymous asymmetric fingerprinting protocol combined with watermarking techniques, is one of the copyright protection technologies keeping both right of a seller and that of a buyer, where a seller and an anonymous buyer perform such a protocol that employs various cryptographic tools in order that the seller does not know the exact watermarked copy that the buyer receives, while inserting an invisible non-removable fingerprint i.e., each different unique watermark, into each copy of the digital content to be sold. In such a protocol innocent buyers are kept anonymous during transactions, however, the unlawful reseller is unambiguously identified with a real identity as a copyright violator. In 2007, Yong and Lee proposed an anonymous asymmetric fingerprinting scheme with trusted third party. In this paper we point out the weakness of their scheme such as: the buyer with intention can remove the fingerprint in the watermarked content, because he/she can decrypt the encrypted fingerprint with a symmetric key using man-in-the-middle-attack; a real identity of a buyer can be revealed to the seller through the identification process even though he/she is honest. Furthermore, we propose an improved secure and efficient anonymous asymmetric fingerprinting scheme which enables to reduce the number of communication between the participants.

• Journal of KIISE:Databases
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• v.29 no.6
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• pp.477-491
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• 2002

The broadcast environment has asymmetric communication aspect that is typically much greater communication bandwidth available from server to clients than in the opposite direction. In addition, mobile computing systems generate mostly read-only transactions from mobile clients for retrieving different types of information such as stock data, traffic information and news updates. Since previous concurrency control protocols, however, do not consider such a particular characteristics, the performance degradation occurs when previous schemes are applied to the broadcast environment. In this paper, we propose optimistic concurrency control based on timestamp interval for broadcast environment. The following requirements are satisfied by adapting weak consistency that is the appropriate correctness criterion of read-only transactions: (1) the mutual consistency of data maintained by the server and read by clients (2) the currency of data read by clients. We also adopt the timestamp Interval protocol to check the weak consistency efficiently. As a result, we improved a performance by reducing unnecessary aborts and restarts of read-only transactions caused when global serializability was adopted.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.2
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• pp.47-60
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• 2023

This study proposed to adopt consortium blockchain for the database in the research support system of national R&D projects in order to increase efficiency, to reduce administrative burden, and to promote transparent research environment focusing on servicing researchers. Specifically, storage methods were classified according to data characteristics. First, data that requires integrity and transparency is stored in the blockchain, Second, confidentiality and data that require modification and deletion are stored in the database, Third, data that requires confidentiality, integrity, and transparency at the same time stores the original in the database, and the hash value of the data is separately stored in the blockchain. If research support system adopts blockchain, it is possible to operate the system stably, to share quick exchange of information between research institutes, to reduce administrative burden, to improve transparency of process, to resolve asymmetry of information, and to secure integrity, confidentiality, and availability of data.

• The Transactions of the Korea Information Processing Society
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• v.7 no.9
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• pp.2913-2919
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• 2000

It is essential to get large prime numbers in the design of asymmetric encryption algorithm. However, the pseudoprime numbers with high possibility to be primes have been generally used in the asymmetric encryption algorithms, because it is very difficult to find large deterministic prime numbers. In this paper, we propose a new method of deterministic prime number generation. The prime numbers generated by the proposed method have a 100% precise prime characteristic. They are also guaranteed reliability, security strength, and an ability of primitive element generation.

• Proceedings of the KOR-KST Conference
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• 1997.12a
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• pp.1-12
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• 1997

우리 나라 자동차운송산업에 존재하는 지입제(위탁관리제)는 과거부터 논란의 대상이 되어 왔다. 1950년대 말부터 시작된 육운 분야의 직영화 정책은 노선버스나 택시의 경우 비교적 성공적인 결과를 가져왔으나 화물자동차운송과 전세버스분야에서 만큼은 아직도 대다수 사업장에서 지입제가 관행화된 제도로 남아 있다. 지입제도는 비효율적이고 전근대적인 경영기법으로 인식되고 있으며 산업발전의 저해요인 보기도하고 불가피하다고 평가되기도 하였다. 본 논문에서는 지입제를 단순하게 비합리적인 제도라고 보기보다는 나름대로의 장점을 가지고 있어 합법적 또는 비합법적인 형태로 지금까지 유지되고 있다고 본다. 지입제는 정보가 비대칭적인 상황에서 기업조직을 통해 생산과 판매를 하기보다는 시장거래를 통한 계약을 통하여 운송서비스를 생산 및 판매를 함으로써 유인일치를 달성시킬 수 있다는 것을 보여주고 있다. 장거리를 운행하는 운송사업의 경우 사업자와 고용운전자는 노동성과에 대한 비대칭적인 정보를 가질 수밖에 없게 된다. 이는 대리문제를 야기시켜 기업조직에 의한 운송서비스의 공급은 생산비용을 상승시킨다. 반면 자동차운송서비스는 생산단위를 분리하기 위한 비용이 비교적 적어 독립적인 운영이 가능하다. 따라서 차량을 1대씩 분리하여 사업권을 시장거래하는 지입제를 운송사업자와 운전자는 선택하게 된다는 것이다.

• Proceedings of the KOR-KST Conference
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• 1997.12b
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• pp.1-14
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• 1997

우리나라 자동차운송산업에 존재하는 지입제(위탁관리제)는 과거부터 논란의 대상이 되어왔다. 1950년대 말부터 시작된 육문 분야의 직영화 정책은 노선버스나 택시의 경우 비교적 성공적인 결과를 가져왔으나 화물자동차운송과 전세버스분야에서 만큼은 아직도 대다수 사업장에서 지입제가 관행화된 제도로 남아 있다. 지입제도는 비효율적이고 전근대적인 경영기법으로 인식되고 있으며 산업발전의 저해요인 보기도하고 불가피하다고 평가되기도 하였다. 본 논문에서는 지입제를 단순하게 비합리적인 제도라고 보기보다는 나름대로의 장점을 가지고 있어 합법적 또는 비합법적인 형태로 지금까지 유지되고 있다고 본다. 지입제는 정보가 비대칭적인 상황에서 기업조직을 통해 생산과 판매를 하기보다는 시장거래를 통한 계약을 통하여 운송서비스를 생산 및 판매를 함으로써 유인일치를 달성시킬 수 있다는 것을 보여주고 있다. 장거리를 운행하는 운송사업의 경우 사업자와 고용운전자는 노동성과에 대한 비대칭적인 정보를 가질 수밖에 없게 된다. 이는 대리문제를 야기시켜 기업조직에 의한 운송서비스의 공급은 생산비용을 상승시킨다. 반면 자동차운송서비스는 생산단위를 분리하기 위한 비용이 비교적 적어 독립적운영이 가능하다. 따라서 차량을 1대씩 분리하여 사업권을 시장거래하는 지입제를 운송사업자와 운전자는 선택하게 된다는 것이다.

• The Transactions of the Korea Information Processing Society
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• v.13 no.8
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• pp.349-355
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• 2024

This paper proposes a new congestion control algorithm, Dynamic Bandwidth Aware Congestion Control (DBAC), to enhance data transmission efficiency in modern network environments that require the use of multiple paths. Traditional single-path TCP has limitations that are addressed by Multipath TCP (MPTCP), which can utilize multiple paths simultaneously to maximize bandwidth and improve transmission reliability. However, MPTCP suffers performance degradation in high-speed, long-distance networks due to path characteristic asymmetry. To overcome this, DBAC combines TCP CUBIC for paths with high BDP and LIA for regular paths, optimizing resource utilization and fairness. Experimental results show that DBAC significantly improves resource utilization and transmission performance, effectively using over 80% of the bandwidth on high BDP paths, compared to less than 20% with traditional LIA.