• 한국사이버테러정보전학회:학술대회논문집
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• 한국사이버테러정보전학회 2004년도 제1회 춘계학술발표대회
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• pp.103-108
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• 2004

현재 HLR system은 이동전화 망에서 지속적으로 변하는 개별 가입자의 위치 정보를 관리 한다. 이를 수행하기 위해, HLR database system은 table 관리 기능과 색인 관리 기능, 그리고 백업 관리 기능을 제공한다. 본 논문에서는, 이동 전화 번호를 위한 적절한 색인 기법으로서 이단계 색인 기법의 사용과, 단말번호를 위한 버켓 연결 해슁 기법을 제안한다. 이동 전화 번호(MDN)와 단말번호(ESN)는 HLR database system에서 key로 사용된다. 또한 HLR database transaction의 특성을 고려한 효율적인 백업 방법을 제안한다. 이단계 색인 기법은 기존의 T 트리 색인 기법보다 검색 속도와 기억 공간 사용 효율 측면에서 우수하다. 버켓 연결 해슁 기법은 기존의 변형된 선형 해슁 기법보다 삽입과 삭제 시의 오버헤드가 적다. 제안한 백업 방법에서는, 빈번한 위치 등록 기능 수행으로 인해 야기되는 성능 저하 문제를 해결하기 위해 두가지 종류의 갱신 플래그를 사용하였다. 아울러 위치 정보의 보안성 처리를 위한 HLR 데이터베이스 Scheme을 제안하였다.

• 폴리머
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• 제39권3호
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• pp.441-452
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• 2015

Twin-screw kneader is an efficient polymer processing equipment. In this paper, the mixing performance of one novel intermeshing counter-rotating twin-screw kneader with different tip angles of the male rotor is simulated using the mesh superimposition technique (MST). Statistical analysis is carried out for the flow field using particle tracking technique, and distributive mixing performance is evaluated using the residence time distribution and segregation scale, while the dispersive mixing performance is estimated using the parameters such as shear rate, stretching rate and mixing index. The results show that the best distributive mixing performance is achieved when the tip angle is 0o, while the optimal dispersive mixing performance is obtained when the tip angle is 20o. The results in this paper provide a data basis for the selection of parameters and optimization of the performance for the screw rotors.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권9호
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• pp.2314-2333
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• 2023

It is significant to predict the performance degradation of complex electromechanical systems. Among the existing performance degradation prediction models, belief rule base (BRB) is a model that deal with quantitative data and qualitative information with uncertainty. However, when analyzing dynamic systems where observable indicators change frequently over time and working conditions, the traditional belief rule base (BRB) can not adapt to frequent changes in working conditions, such as the prediction of aeroengine performance degradation considering working condition. For the sake of settling this problem, this paper puts forward a new hidden belief rule base (HBRB) prediction method, in which the performance of aeroengines is regarded as hidden behavior, and operating conditions are used as observable indicators of the HBRB model to describe the hidden behavior to solve the problem of performance degradation prediction under different times and operating conditions. The performance degradation prediction case study of turbofan aeroengine simulation experiments proves the advantages of HBRB model, and the results testify the effectiveness and practicability of this method. Furthermore, it is compared with other advanced forecasting methods. The results testify this model can generate better predictions in aspects of accuracy and interpretability.

• 한국도로학회논문집
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• 제18권2호
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• pp.83-90
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• 2016

PURPOSES : Nowadays, cavity phenomena occur increasingly in pavement layers of downtown areas. This leads to an increment in the number of potholes, sinkholes, and other failure on the road. A loss of earth and sand from the pavement plays a key role in the occurrence of cavities, and, hence, a structural-performance evaluation of the pavement is essential. METHODS: The structural performance was evaluated via finite-element analysis using KPRP and KICTPAVE. KPRP was developed in order to formulate a Korean pavement design guide, which is based on a mechanical-empirical pavement design guide (M-EPDG). RESULTS: Installation of the anti-freezing layer yielded a fatigue crack, permanent deformation, and international roughness index (IRI) of 13%, 0.7 cm, and 3.0 m/km, respectively, as determined from the performance analysis conducted via KPRP. These values satisfy the design standards (fatigue crack: 20%, permanent deformation: 1.3 cm, IRI: 3.5 m/km). The results of FEM, using KICTPAVE, are shown in Figures 8~12 and Tables 3~5. CONCLUSIONS: The results of the performance analysis (conducted via KPRP) satisfy the design standards, even if the thickness of the anti-freezing layer is not considered. The corresponding values (i.e., 13%, 0.7 cm, and 3.0 m/km) are obtained for all conditions under which this layer is applied. Furthermore, the stress and strain on the interlayer between the sub-grade and the anti-freezing layer decrease gradually with increasing thickness of the anti-freezing layer. In contrast, the strain on the interlayer between the sub-base and the anti-freezing layer increases gradually with this increase in thickness.

• 한국정보과학회논문지:데이타베이스
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• 제31권4호
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• pp.384-394
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• 2004

최근 중앙처리장치와 주기억장치간의 병목 현상에 의한 성능 저하를 극복하기 위해 캐시를 고려한 색인 구조들이 제안되었다. 이런 색인 구조들의 궁극적인 목표는 엔트리 크기를 줄여 팬-아웃(fan-out)을 증가시키고, 캐시 접근 실패를 최소화하여 시스템의 성능을 높이는 것이다. 엔트리의 크기를 줄이는 기법에 따라 기존의 색인 구조들을 두 가지로 구분할 수 있다. 하나는 좌표 값을 고정된 비트로 양자화 함으로써, MBR 키를 압축하는 것이다. 또 다른 하나는 MBR들의 각 좌표 값 중에 그들의 부모 MBR과 같지 않은 좌표 값만을 저장하는 것이다. 우선, 본 논문에서는 두 기법의 특성들을 적절히 조합한 새로운 색인 구조를 제안하고, 기존에 제시된 두 접근법을 따르는 주기억장치 상주형 다차원 색인 구조를 다양한 환경에서 성능 평가한다. 또한, 기존의 색인 구조와 비교를 통해 제안하는 색인 구조의 우수성을 보인다.

• 시스템엔지니어링학술지
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• 제11권2호
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• pp.85-93
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• 2015

Warehouse Management System (WMS) is a key control for Material Handling System (MHS) and Inventory Control System (ICS). How to design and implement for WMS is crucial factor for achieving the key performance index for Manufacturing Industry. In particular, iron and steel making industry, where the volume and weight is large and hence FIFO (First Input First Out) is not working, how to design WMS is a key factor. In this paper, we systematically define the problem of WMS via developing StR (Stakeholders' Requirements) or ORD (Operational Requirement Documents), SyR (System Requirement), and SA (System Architecture) based on the emerging technologies. In particular, IoT (Internet of Things), CPS (Cyber Physical System) concepts and enabling technologies haves been incorporated in developing Smart WMS. The deliverables of the research can provide a conceptual framework for developing the next generation industrial WMS.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권5호
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• pp.2468-2483
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• 2017

The construction of completely random sensing matrices of Compressive Sensing requires a large number of random numbers while that of deterministic sensing operators often needs complex mathematical operations. Thus both of them have difficulty in acquiring large signals efficiently. This paper focuses on the enhancement of the practicability of the structurally random matrices and proposes a semi-deterministic sensing matrix called Partial Kronecker product of Identity and Hadamard (PKIH) matrix. The proposed matrix can be viewed as a sub matrix of a well-structured, sparse, and orthogonal matrix. Only the row index is selected at random and the positions of the entries of each row are determined by a deterministic sequence. Therefore, the PKIH significantly decreases the requirement of random numbers, which has a complex generating algorithm, in matrix construction and further reduces the complexity of sampling. Besides, in order to process large signals, the corresponding fast sampling algorithm is developed, which can be easily parallelized and realized in hardware. Simulation results illustrate that the proposed sensing matrix maintains almost the same performance but with at least 50% less random numbers comparing with the popular sampling matrices. Meanwhile, it saved roughly 15%-35% processing time in comparison to that of the SRM matrices.

• Computers and Concrete
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• 제10권4호
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• pp.409-417
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• 2012

The quality of high performance concrete largely depends on water cement ratio, porosity, material composition and mix methods. The uniformity of color, texture and compressive strengths are quality indicators commonly used to assess the overall characteristics of concrete mixes. The homogeneity and share of coarse aggregates play a key role in concrete quality and must be analyzed in a microscopic point of view. This research studies the quality of high performance concrete by taking drilled cores in both horizontal and vertical directions from a 1.0 $m^3$ specimen. The coarse aggregate, expressed in digitized $100{\times}116$ dpi resolution images are processed based on brightness in colors through commercial software converted into text files. With the image converting to text format, the share of coarse aggregate is quantified leading to a satisfactory assessment of homogeneity - a quality index of high performance concrete. The compressive strengths of concrete and the shares of coarse aggregate of the samples are also compared in this research study to illustrate its correlation in concrete quality. It is concluded that a higher homogeneity of aggregate exists in the vertical plane than that of the horizontal planes of the high performance concrete. In addition, the concrete specimen showing denser particle packing has relatively higher compressive strengths. The research methodology provides an easy-to-use, direct measurement of high performance concrete when conducting quality assessment in the construction site.

• Journal of Korea Trade
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• 제24권5호
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• pp.35-54
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• 2020

Purpose - It seems common sense that corporate social responsibility (CSR) is a key driver of business sustainability. Nevertheless, there has been little research on the performance of socially responsible activities, including economic and environmentally responsibility activities, in internationally diversified firms. Design/methodology - The purpose of this study was to evaluate the effects of CSR activities on management performance. For this evaluation, an empirical analysis was conducted with total of 2,520 cases, selected from companies listed on the Korea Composite Stock Price Index market for six years from 2013 to 2018. As proxies for management performance, financial data such as a total asset net profit ratio and a total asset operating ratio were used. A multivariate regression analysis was conducted to test hypotheses. Findings - The results of this analysis indicated that firms in the CSR outstanding group were ranked significantly higher than other groups in management performance. In addition, CSR activities of internationally diversified firms positively influenced the total asset net profit ratio and total asset operating ratio. Originality/value - The results suggest that the CSR activities of these firms can play a significant role in enhancing management performance in the economic status of Korea, where the degree of export dependency is high.

• Asian-Australasian Journal of Animal Sciences
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• 제33권5호
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• pp.802-811
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• 2020

Objective: Two experiments were conducted to investigate the effects of dietary sucralose on diet preference and growth performance of weaned piglets, and a third experiment was a 28-d safety study to examine if high-dose sucralose could affect the health state of weaned piglets. Methods: In experiment one, 48 piglets had free access to a corn-soybean based diet and the same diet supplemented with 150 mg/kg sucralose for 15 d. In experiment two, 180 piglets were blocked into 5 treatments with 6 replications. They were fed basal diets supplemented with 0, 75, 150, 225, and 300 mg/kg sucralose for 28 days. In experiment three, 108 piglets were randomly assigned to 3 treatments and fed diets supplemented with 0, 150 (suitable level), and 1,500 (ten-fold suitable level) mg/kg sucralose for 28 d. Results: The experiment 1 showed that piglets preferred (p<0.05) diets containing sucralose during experimental period. In experiment 2, piglets fed a diet supplemented with 150 mg/kg sucralose had a higher average daily gain (ADG) and average daily feed intake (ADFI) than pigs in the control group and other treatment groups during the experiment period. The concentrations of sucralose over 150 mg/kg may decrease feed intake. However, no difference in feed conversion ratio was observed. In experiment 3, piglets fed diet supplemented with 150 mg/kg sucralose had a higher ADG and ADFI than that of pigs in the control group and 1,500 mg/kg treatment groups during the experiment period. Clinical blood metabolites, organ index and histological morphology were not significantly different between sucralose treatments. Conclusion: Sucralose can promote feed intake and thereby improve growth performance of weaned piglets. Moreover, inclusion of 1,500 mg/kg sucralose was demonstrated to have no observed adverse effects. Supplementing 150 mg/kg sucralose for weaned piglets is recommended in this study.