• 한국컴퓨터정보학회논문지
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• 제24권4호
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• pp.65-71
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• 2019

IAs smart device penetration rate is more than 90%, mobile transaction ratio using smart device is increasing. Smart contracts are used in various areas of real life including smart trading. By applying smart contracts to the platform for smart transactions through block-chain technology, the threat of hacking or forgery can be reduced. However, various threats to devices in smart transactions can pose a threat to the use of block chain Etherium, an important element in privilege and personal information management. Smart contract used in block chain Ethereum includes important information or transaction details of users. Therefore, in case of an attack of privilege elevation, it is very likely to exploit transaction details or forge or tamper with personal information inquiry. In this paper, we propose a detection and countermeasure method for privilege escalation attack, which is especially important for block chain for secure smart transaction using block chain Ethereum. When comparing the results of this study with the results of similar applications and researches, we showed about 12~13% improvement in performance and suggested the future countermeasures through packet analysis.

• 한국군사과학기술학회지
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• 제10권1호
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• pp.101-106
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• 2007

In this paper, we propose chain code based decision technique of edge orientation. Edge Information is one of the most important information for handling image signals, and is applied to various civilian and military area, such as image surveillance for military reconnaissance, restoration of noised image signal, fingerprint recognition, and so on. The conventional methods to find edge orientations exploit a certain size of mask which weights for a certain direction, so they showed limitations in the case of diagonal edges except 45 degrees. We find edge orientations using chain code. According to the experiments, the proposed method shows better performance than the conventional approaches. The exact edge orientations including diagonal directions are well found.

• Management Science and Financial Engineering
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• 제10권2호
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• pp.1-28
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• 2004

The integrated supply chain of business partners for e-Commerce in cyber space is defined as Logistics Chain if the cooperative activities are logistics-related. Logistics Chain could be managed effectively and efficiently by cooperative technologies of logistics chain execution. In this paper, we propose a routing and scheduling algorithm based on the Tabu search by adding geographical information into existing constraint for pick-up and delivery process to minimize service time and cost in logistics chain. And, we also consider an uncertainty processing for the tracing of moving object to control pick-up and delivery vehicles based on GPS/GIS/ITS. Uncertainty processing is required to minimize amount of telecommunication and database on vehicles tracing. Finally, we describe the Logistics Chain Execution (LCE) system to perform plan and control activities for postal logistics chain. To evaluate practical effects of the routing and scheduling system, we perform a pretest for the performance of the tabu search algorithm. And then we compare our result with the result of the pick-up and delivery routing plan generated manually by postmen.

• Journal of the Korean Data Analysis Society
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• 제20권6호
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• pp.3101-3116
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• 2018

본 연구에서는 기업 경쟁력의 제고를 통하여 최적화된 경영환경을 조성하고, 기업의 효율성을 높이는데 필요한 혁신 수단인 공급사슬관리를 위한 동적역량의 활용 방향성과 전략을 찾을 수 있는 방안들에 대해 알아보고자 한다. 시장과 기술은 전략적 방향과 문화로 기업이 보유한 정형화된 동적역량에 맞추고, 프로세스에는 공급사슬관리를 위한 동적역량과 관련된 기술을 반영하여 활용할 때에 보다 높은 기업성과를 창출할 수 있을 것이다. 본 연구에서는 시장지향성과 기술지향성이 기업성과에 미치는 영향과 동적역량이 기업성과에 어떠한 영향을 미치는지를 실증적으로 분석하는데 그 목적이 있다. 연구 결과는 시장지향성과 기술지향성은 동적역량에 긍정적 영향을 미치고, 동적역량은 기업성과에 긍정적 영향을 미치는 것으로 나타났다. 즉 동적역량은 시장지향성, 기술지향성과 기업성과 간의 관계를 매개하는 것으로 검증되었으며, 동적역량의 매개효과로 기업의 시장지향성과 기술지향성이 기업성과에 중요한 영향을 미치는 것으로 실증 분석되었다.

• Elastomers and Composites
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• 제56권4호
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• pp.209-216
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• 2021

In this study, we observed the mechanical properties, thermal stability, and low temperature sealing performance of fluorosilicone elastic composites. When the blend ratio of Phenyl vinyl methyl silicone (PVMQ) was increased, the tensile strength, modulus at 100%, and compression set were decreased. The thermal stability of fluorosilicone elastic composites showed a similar tendency. These were caused by poorer green strength of PVMQ than Fluorosilicone rubber (FVMQ). The change in the tensile strength and elongation at -40℃ showed a decreasing tendency with increasing PVMQ blend ratio. By increasing the PVMQ blend ratio, low-temperature performance was improved. The Dynamic mechanical analysis (DMA) results showed that T_g was decreased and low-temperature performance was improved with increasing PVMQ blend ratio. However tanδ was decreased becaused of the poor green strength and elasticity of PVMQ. From a hysteresis loss at -40℃, the hysteresis loss value was increased and fluorosilicone elastic composites showed the decreasing tendency of elasticity with increasing PVMQ blend ratio. From the TR test, TR10 was decreased with increasing PVMQ blend ratio. FS-4 (45% PVMQ blended composites) showed a TR10 of -68.0℃ that was 5℃ lower than that of FS-1 (100% FVMQ). The gas leakage temperature was decreased with increasing PVMQ blend ratio. The gas leakage temperature of FS-4 was -69.2℃ that was 5℃ lower than that of FS-1. Caused by the polymer chain started to transfer from a glassy state to a rubbery state and had a mobility of chain under T_g, the gas leakage temperature showed a lower value than T_g. The sealing performance at low temperature was dominated by T_g that directly affected the mobility of the polymer chain.

• Food Science and Biotechnology
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• 제14권4호
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• pp.470-473
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• 2005

Starch was isolated from turnip (Brassica rapa L.), and to elucidate the structure-function relationship its structural and physical properties were characterized. Morphological structure of the starch was analyzed by SEM (Scanning Electron Microscopy). Most of the starch granules were spherical in shape with diameter ranging from 0.5-10mm. Apart from larger granules ($<10\;{\mu}m$) which dominated the population size of turnip starch, significant amount of small ($0.5-2\;{\mu}m$) and mid-size granules (${\sim}\;{\mu}m$) were also detected. It was revealed that presumably, erosion damages occurred due to the attack of amylase-type enzymes on the surface of some granules. Branch chain-length distribution was analyzed by HPAEC (High-Performance Anion-Exchange Chromatography). The chain-length distribution of turnip starch revealed a peak at DP12 with obvious shoulder at DP18-21. The weight-average chain length ($CL_{avg}$) was 16.6, and a large proportion (11.8%) of very short chains (DP6-9) was also observed. The melting properties of starch were determined by DSC (Differential Scanning Calorimetry). The onset temperature ($T_o$) and the enthalpy change (${\Delta}H$) of starch gelatinization were $50.5^{\circ}C$ and 12.5 J/g, respectively. The ${\Delta}H$ of the retrograded turnip starch was 3.5 J/g, which indicates 28.2% of recrystallization. Larger proportion of short chains as well as smaller average chain-length can very well explain relatively lower degree of retrogradation in turnip starch.

• 한국식품과학회지
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• 제33권1호
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• pp.50-54
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• 2001

8품종 변이체 쌀 전분의 청가에 의한 아밀로오스 함량의 차이는 남풍벼>화청벼>분질미>남풍 CB243>화청 du-1>남풍 EM90>화청찰벼>shr.의 순이었다. 아밀로펙틴의 미세구조는 효소처리에 의해서 debranching시킨 전분의 glucose chain length분포 비교에 의해서 수행되었고, 품종별로 미세구조상에 차이가 있었다. 아밀로오스 함량이 낮을수록 씹힘성이 좋은 쌀빵의 제조가 가능하였으며, 아밀로펙틴 분획에 짧은 쇄장을 많이 함유하는 품종일수록 질감 및 기호도가 높은 쌀빵의 제조가 가능하였다.

• 한국콘텐츠학회논문지
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• 제18권6호
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• pp.324-332
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• 2018

블록체인 기술은 신뢰모델과 비즈니스 프로세스를 다양한 산업분야에서 혁신적으로 바꿀 수 있는 잠재력을 지니고 있다. 하지만, 효율성보다는 자율성을 추구한 시스템의 초기단계로 평가되고, 분산원장기술도 기존의 관계형 DB 거래기술에 비해 가격과 도입시간에서의 모니터링 및 점검이 필요하다고 판단된다. 하지만, 국내 외 민간에서는 구체적인 영역에서 블록체인 기술이 적용되어 활성화되고 있고 기록의 불변성, 투명성, 비즈니스 규칙의 자율적인 실행을 특징으로 초기의 과장된 기술이라는 의심에서 벗어나 금융업계는 물론 다양한 산업군에서 이력과 신원, 자격인증과 감사 등에 활용되기 시작했다. 이에, 본 논문에서는 보안 취약점, 규제환경의 미흡, 기술적 공감대 및 공통표준의 미흡 등에서 문제점을 분석하였다. 그리고 블록체인 기술이 갖는 비즈니스적 의미와 가능성을 저작권, 물류, 헬스케어, 환경분야에서의 실제 도입성과 기반의 모니터링을 통해 개념에서 현실 제도권으로 진입되어 산업생태계의 혁신을 이를 것으로 전망하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.556-559
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• 2007

The notion of linearity is fundamental in science and engineering. Much of system and control theory is based on the analysis of linear system, which does not care whether it is nonlinear and complex. The dynamic programming is one of concerned technology when users are interested in choosing best choice from system operation for nonlinear or dynamic system‘s performance and control problem. In this paper, we will introduce the dynamic programming which is based on discrete system. When the discrete system is constructed with discrete state, transfer between states, and the event to induct transfer, the discrete system can describe the system operation as dynamic situation or symbolically at the logical point of view. We will introduce technologies which are related with controllable of Controlled Markov Chain as shown example of simple game. The dynamic programming will be able to apply to optimal control part which has adaptable performance in the discrete system.

• 대한산업공학회지
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• 제41권2호
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• pp.173-184
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• 2015

The application of radio frequency identification (RFID) sensor-tags in cold chain systems has recently received a great deal of attention. To design cold chain systems with RFID sensor-tags that minimize the initial investment and operational cost while fulfilling the functional and operational requirements, simulation study is one of the preferable and effective approaches. To simulate the possible design configurations, the individual components in a cold chain system can be extracted and implemented as a DEVS (Discrete Event System Specification) model. Based on the proposed DEVS model, a new cold chain simulation model can be efficiently created by simply connecting each DEVS model around the RFID sensor-tag of interest in sequence according to the structure of the cold chain system, and then executed (or simulated) on Java programming environments by the DEVSJAVA simulator. As a result of simulation, some key performance indexes such as reliability, accuracy or timeliness can be calculated and used to choose better components or to compare different system configurations of cold chain systems.