• Industrial Engineering and Management Systems
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• v.8 no.2
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• pp.80-92
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• 2009

This paper addresses the inventory rationing issue embedded in the regional supply chain inventory replenishment problem (RSIRP). The concerned supply chain, which was fed by the national supply chain, consisted of a single warehouse distributing a single product to multiple stores (M-stores) with independent and normally distributed customer demand. It was assumed that the supply chain operated under the order-up-to level inventory replenishment system and had only one truck at the regional warehouse. The truck could make one replenishment trip to one store per period (a round trip per period). Based on current inventories and the vehicle constraint, the warehouse must make two decisions in each period: which store in the region to replenish and what was the replenishment quantity? The objective was to position inventories so as to minimize lost sales in the region. The warehouse inventory was replenished in every fixed-interval from a source outside the region, but the store inventory could be replenished daily. The truck destination (store) in each period was selected based on its maximum expected shortage. The replenishment quantity was then determined based on the predetermined order-up-to level system. In case of insufficient warehouse inventories to fulfill all projected store demands, an inventory rationing rule must be applied. In this paper, a new inventory rationing rule named Expected Cost Minimization (ECM) was proposed based on the practical purpose. The numerical results based on real data from a selective industry show that its performance was better and more robust than the current practice and other sharing rules in the existing literature.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.5
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• pp.1073-1080
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• 2011

In this paper, we propose a novel digital watermarking method by virtual optics which secures multimedia information such as images, videos and sounds. To secure the multimedia data, we use Fresnel transform which describes the diffraction phenomena of the waves. Also, this method attaches the random phase function to Fresnel transform so that original image and watermark image would be gaussian random vectors. The complex numbers of watermark by Fresnel transform are separated the real part and the imaginary part. The former is embedded in original image as a encoding key imperceptibly and the latter is used for detecting the watermark as a decoding key. This method for digital watermarking ensures that watermark can be successfully registered and extracted from the watermarked image. Further, it provides the robustness to signal processing operation and geometric distortion and proves the strong resilience against cropping attack. The performance evaluation of the experiment is carried out with PSNR, and the numerical simulation results show the efficiency of the proposed method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.8
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• pp.1851-1856
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• 2013

An XML is widely used for web services, such as SOAP(Simple Object Access Protocol) and REST (Representational State Transfer), and also de facto standard for representing data. Since the XML parser using DOM(Document Object Model) requires a preprocessing task creating a DOM-tree, and then storing it into memory, embedded systems with limited resources typically employ a streaming XML parser without preprocessing. In this paper, we propose a new architecture for the streaming XML parser using an APSearch(Adaptive Parallel Search) on FPGA(Field Programmable Gate Array). Compared to other approaches, the proposed APSearch parser dramatically reduces overhead on the software side and achieves about 2.55 and 2.96 times improvement in the time needed for an XML parsing. Therefore, our APSearch parser is suitable for systems to speed up XML parsing.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.7
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• pp.949-955
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• 2018

Hardware-in-the-loop (HIL) simulation is a technique that can be employed for developing and testing complex real-time embedded systems. HIL simulation provides an effective platform for verifying power management system (PMS) performance of liquefied natural gas carriers, which are high value-added vessels such as offshore plants. However, HIL tests conducted by research institutes, including domestic shipyards, can be protracted. To address the said issue, this study proposes a field programmable gate array (FPGA) based PMS-HIL simulator that comprises a power supply, consumer, control console, and main switchboard. The proposed HIL simulation platform incorporated actual equipment data while conducting load sharing PMS tests. The proposed system was verified through symmetric, asymmetric, and fixed load sharing tests. The proposed system can thus potentially replace the standard factory acceptance tests. Furthermore, the proposed simulator can be helpful in developing additional systems for vessel automation and autonomous operation, including the development of energy management systems.

• Restorative Dentistry and Endodontics
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• v.43 no.2
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• pp.19.1-19.10
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• 2018

Objectives: This study investigated the effect of continuous application of 10-methacryloyloxydecyldihydrogen phosphate (MDP)-containing primer and luting resin cement on bond strength to tribochemical silica-coated yttria-stabilized tetragonal zirconia polycrystal (Y-TZP). Materials and Methods: Forty bovine teeth and Y-TZP specimens were prepared. The dentin specimens were embedded in molds, with one side of the dentin exposed for cementation with the zirconia specimen. The Y-TZP specimen was prepared in the form of a cylinder with a diameter of 3 mm and a height of 10 mm. The bonding surface of the Y-TZP specimen was sandblasted with silica-coated aluminium oxide particles. The forty tribochemical silica-coated Y-TZP specimens were cemented to the bovine dentin (4 groups; n = 10) with either an MDP-free primer or an MDP-containing primer and either an MDP-free resin cement or an MDP-containing resin cement. After a shear bond strength (SBS) test, the data were analyzed using 1-way analysis of variance and the Tukey test (${\alpha}=0.05$). Results: The group with MDP-free primer and resin cement showed significantly lower SBS values than the MDP-containing groups (p < 0.05). Among the MDP-containing groups, the group with MDP-containing primer and resin cement showed significantly higher SBS values than the other groups (p < 0.05). Conclusions: The combination of MDP-containing primer and luting cement following tribochemical silica coating to Y-TZP was the best choice among the alternatives tested in this study.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.9
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• pp.773-781
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• 2013

The Hough transform for line detection is widely used in many machine vision applications due to its robustness against data loss and distortion. However, it is not appropriate for real-time embedded vision systems, because it has inefficient computation structure and demands a large number of memory accesses. Thus, this paper proposes an improved voting scheme of the Hough transform, and then applies this scheme to a Hough transform hardware architecture so that it can provide real-time performance with less hardware resource. The proposed voting scheme reduces computation overhead of the voting procedure using correlation between adjacent pixels, and improves computational efficiency by increasing reusability of vote values. The proposed hardware architecture, which adopts this improved scheme, maximizes its throughput by computing and storing vote values for many adjacent pixels in parallel. This parallelization for throughput improvement is accomplished with little hardware overhead compared with sequential computation.

• The KIPS Transactions:PartC
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• v.16C no.3
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• pp.335-346
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• 2009

Mobile environments are evolving the main communication environment as a develops of communication technology. In mobile environments, sensitive information can be compromised on-line, so demand for security has increased. Also, mobile devices that provide various services are in danger from malware and illegal devices, phishing and sniffing etc, and the privacy. Therefore, MTM(Mobile Trusted Module) is developed and promoted by TCG(Trusted Computing Group), which is an industry standard body to enhance the security level in the mobile computing environment. MTM protects user privacy and platform integrity, because it is embedded in the platform, and it is physically secure. However, a security approach is required when secret data is migrated elsewhere, because MTM provides strong security functions. In this paper, we analyze the TCG standard and migration method for cryptographic key, then we propose a secure migration scheme for cryptographic key using key Backup/Recovery method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.1
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• pp.218-224
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• 2013

Generally, SAW device, which uses Time Domain Sampling, requires high speed A/D converter because SAW device using TDS needs high sampling speed as much as its high data speed. However, the high price of A/D converter discourages makers from using it. On the other hand, SAW device, which uses Frequency Domain Sampling, does not required high speed A/D converter because SAW device using FDS does not need high sampling speed. It is very efficient in price comparison to its performance because high processing speed of SAW device using FDS can be implemented using low price Embedded Systems. The purpose of the paper is to solve the issues above by designing and realizing SAW device(FDS) using SAW sensor for TDS.

• KIEAE Journal
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• v.17 no.5
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• pp.69-76
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• 2017

Purpose: This study aimed at developing an Artificial Neural Network (ANN) model for predicting the amount of cooling energy consumption of the variable refrigerant flow (VRF) cooling system by the different set-points of the control variables, such as supply air temperature of air handling unit (AHU), condenser fluid temperature, condenser fluid pressure, and refrigerant evaporation temperature. Applying the predicted results for the different set-points, the control algorithm, which embedded the ANN model, will determine the most energy efficient control strategy. Method: The ANN model was developed and tested its prediction accuracy by using matrix laboratory (MATLAB) and its neural network toolbox. The field data sets were collected for the model training and performance evaluation. For completing the prediction model, three major steps were conducted - i) initial model development including input variable selection, ii) model optimization, and iii) performance evaluation. Result: Eight meaningful input variables were selected in the initial model development such as outdoor temperature, outdoor humidity, indoor temperature, cooling load of the previous cycle, supply air temperature of AHU, condenser fluid temperature, condenser fluid pressure, and refrigerant evaporation temperature. The initial model was optimized to have 2 hidden layers with 15 hidden neurons each, 0.3 learning rate, and 0.3 momentum. The optimized model proved its prediction accuracy with stable prediction results.

• Radiation Oncology Journal
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• v.9 no.2
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• pp.343-350
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• 1991

The quasi-conformation therapy was performed to get a homogeneous dose distributions for irregeular shaped tumor lesion by using the arc moving beam and beam modifying filter which was made by cerrobend alloy($\rho$=9.4 g/cc) metal. In our dose calcuation programme, it was fundmentally based on Clarkson's method to calcuate the irregular multi-step block field in rotation therapy. In this study, the expected relative depth doses under multipartial attenuator agree well with measured data at same plane. The results of comparison the dose computation with that of TLD measurement are very closed within ${\pm}5\%$ uncertainties in the irradiation to phantom with quasi-comformation method. And it has shown that irregular typed multi-step filter can be applied to quasi-conformation therapy in high energy radiation plannings.