• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.10 no.1
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• pp.37-43
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• 2014

Nuclear power plants(NPPs) are consisted of power production functions and safety functions preventing leakage of radiation. Operators working in NPPs shall maintain these functions during an operation period through various activities such as improvement & modification, corrective maintenance, preventive maintenance and surveillance test. According to the performance of these work activities, there are configuration changes in NPPs systems. Its changes cause the increase of safety risks(CDF) and plant trip risks. Recently, the importance of risk management is increasing gradually in the operation process of NPPs. Therefore, this paper presents the work management methods using the various risk monitoring systems during power operation and overhaul period. Also this paper suggests the optimum application ways of risk systems for work management.

• Journal of KIISE:Information Networking
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• v.29 no.6
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• pp.663-673
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• 2002

Server-side anti-viruses are useful to protect their domains, because they can detect malicious codes at the gateway of their domains. In prevailing local network, all clients cannot be perfectly controlled by domain administrators, so server-side inspection, for example in e-mail server, is used as an efficient technique of detecting mobile malicious codes. However, current server-side anti-virus systems perform only signature-based detection for known malicious codes, simple filtering, and file name modification. One of the main reasons that they don't have detection features, for unknown malicious codes, is that activity monitoring technique is unavailable for server machines. In this paper, we propose a detection technique that is executed at the server, but it can monitor activities at the clients without any anti-virus features. we describe its implementation.

• IE interfaces
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• v.10 no.3
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• pp.75-93
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• 1997

Unlike individual applications, it is extremely hard to obtain user requirements for group systems, since there exists very complicated dynamics in group. This may result in spreading a great amount of products with a broad range of contents. Thus, this study presents a comparative analysis of groupware products. As a result, these products have been categorized into three areas which include cooperation/document management systems, collaborative writing systems, and decision-making/meeting systems. While the systems reviewed here focus on the cooperation/document management systems, the other two areas will be dealt in details in part Ⅱ. The first area ends up with two large categories such as proprietary groupware products and intranet groupware products. However, it has been observed that there is a natural convergence between these two categories. Consequently, the comparative analysis has been performed in terms of functions provided on the two categories and a combined category. Each group of the functions has been divided into three parts which consist of basic functions, quasi-basic functions, and others. Such a decision has been made based on the frequency rate of the functions provided in the products. With a more strict rule, the basic functions comprise electronic mail, sanction, bulletin board, document management, scheduling, security, Web browser, and Internet connectivity. This study also provides a framework for integrated functional model of groupware systems. The basic functions are merged into the model. However, the model is so flexible that it can partially include the quasi-functions in addition to the basic functions. In the future, it is expected that a large number of products will stem from the modification of the functional model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.12
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• pp.1313-1323
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• 1991

n this thesis CAM(content Addressable Memory) generator and graphic display tool for run-plot sequence in automatic generation of CAM are presented. We show that implementing the layout generation, graphic menu, mouse driver, and data structure by using the basic classes is clear and easy in modification than the conventional procedural language. For the implementation of generator which is independent of design rule or process, we use the parameterized cell so that basic cell can be changed according to user's inputs. and perform the layout by means of placement and routing using pitch mathching. Finally, the display of CIF which generated and constitution of graphic menu for total run-plot sequence are explained.

• Steel and Composite Structures
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• v.43 no.5
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• pp.603-623
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• 2022

This article is dedicated to predict the natural frequencies of joined conical shell structures made of Functionally Graded Material (FGM). The structure includes two conical segments. The equivalent material properties are found by using the rule of mixture based on Voigt model. In addition, three well-known patterns are employed for distribution of material properties throughout the thickness of the structure. The main objective of the present research is to propose a novel exponential pattern and obtain the related equivalent material properties. Furthermore, the Donnell type shell theory is used to obtain the governing equations of motion. Note that these equations are obtained by employing First-order Shear Deformation Theory (FSDT). In order to discretize the governing system of differential equations, well-known and efficient semi-analytical scheme, namely Generalized Differential Quadrature Method (GDQM), is utilized. Different boundary conditions are considered for various types of single and joined conical shell structures. Moreover, an applicable modification is considered for the continuity conditions at intersection position. In the first step, the proposed formulation is verified by solving some well-known benchmark problems. Besides, some new numerical examples are analyzed to show the accuracy and high capability of the suggested technique. Additionally, several geometric and material parameters are studied numerically.

• Journal of the Korean association of regional geographers
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• v.22 no.3
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• pp.681-702
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• 2016

Two different modelling approaches to dune dynamics have been established thus far; continuous models that emphasize the precise representation of wind field, and feedback-based models that focus on the interactions between dunes, rather than aerodynamics. Though feedback-based models have proven their capability to capture the essence of dune dynamics, the compatibility issues on these models have less been addressed. This research investigated, mostly from the theoretical point of view, the algorithmic compatibility of three feedback-based dune models: sand slab models, Nishimori model, and de Castro model. Major findings are as follows. First, sand slab models and de Castro model are both compatible in terms of flux perspectives, whereas Nishimori model needs a tuning factor. Second, the algorithm of avalanching can be easily implemented via repetitive spatial smoothing, showing high compatibility between models. Finally, the wind shadow rule might not be a necessary component to reproduce dune patterns unlike the interpretation or assumption of previous studies. The wind shadow rule, rather, might be more important in understanding bedform-level interactions. Overall, three models show high compatibility between them, or seem to require relatively small modification, though more thorough investigation is needed.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.12
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• pp.105-112
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• 2009

In this paper, we investigated abnormal ESD failure on guard-rings in the smart power IC fabricated with $0.35{\mu}m$ Bipolar-CMOS-DMOS (BCD) technology. Initially, ESD failure occurred below 200 V in the Machine Model (MM) test due to current crowding in the parasitic diode associated with the guard-rings which are generally adopted to prevent latch-up in high voltage devices. Optical Beam Induced Resistance Charge (OBIRCH) and Scanning Electronic Microscope (SEM) were used to find the failure spot and 3-D TCAD was used to verify cause of failure. According to the simulation results, excessive current flows at the comer of the guard-ring isolated by Local Oxidation of Silicon (LOCOS) in the ESD event. Eventually, the ESD failure occurs at that comer of the guard-ring. The modified comer design of the guard-ring is proposed to resolve such ESD failure. The test chips designed by the proposed modification passed MM test over 200 V. Analyzing the test chips statistically, ESD immunity was increased over 20 % in MM mode test. In order to avoid such ESD failure, the automatic method to check the weak point in the guard-ring is also proposed by modifying the Design Rule Check (DRC) used in BCD technology. This DRC was used to check other similar products and 24 errors were found. After correcting the errors, the measured ESD level fulfilled the general industry specification such as HBM 2000 V and MM 200V.

• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2726-2732
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• 2014

The promoting effect of rhodium on the structure and activity of the supported Cu-Co based catalysts for CO hydrogenation was investigated in detail. The samples were characterized by DRIFTS, $N_2$-adsorption, XRD, $H_2$-TPR, $H_2$-TPD and XPS. The results indicated that the introduction of rhodium to Cu-Co catalysts resulted in modification of metal dispersion, reducibility and crystal structure. DRIFTS results of CO hydrogenation at reaction condition (P=2 MPa, $T=260^{\circ}C$) indicated the addition of 1 wt % rhodium improved hydrogenation ability of Cu-Co catalysts. The ethanol selectivity and CO conversion were both improved by 1 wt % Rh promoted Cu-Co based catalysts. The alcohol distribution over un-promoted and rhodium promoted Cu-Co based catalysts obeys A-S-F rule and higher chain growth probability was got on rhodium promoted catalyst.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.3
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• pp.768-776
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• 1994

This paper describes computer-aided forging design for rib/web shaped parts. In manufacturing a part by means of forging process, the first step is to design the forging. This is done by modifying the given machined part geometry according to the requirements of the forging process. Traditionally, this is done by experienced forging designers using empirical forging design guidelines. Generally, it would be neither possible nor practical to develop a system which encompasses the design of all types of forgings. Accordingly, forging design can be simplified by considering critical two dimensional cross sections of the machined part geometry. This system is composed of three modules(process variable decision module, forging design module and redesign module) and each module is carried out in regular sequence. In the process variable decision module, first of all, the undercut is checked and modified, and then deep recesses and holes difficult to forge are eliminated. Also parting line, forging plane, forging plan view area, forging weight and maximum size(maximum height or width)are determined. In the forging design module, the magnitude of various allowances, draft angle, minimum web thickness, corner and fillet radius are determined and then geometry modification is performed. Finally, since the design rules and databases used in this system are based on parameters of the forging geometry, such as the trimmed forging plan area, forging weight, forging maxmum size, plausible estimates need to be made for these parameters. Therefore, in the re-design module, the design process is iterated until a satisfactory forging is obtained.

• Journal of KIISE:Software and Applications
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• v.34 no.2
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• pp.169-177
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• 2007

Hangul text normalization in current Unicode makes wrong Hangul syllable problems when using with precomposed modern Hangul syllables and composing old Hangul by using conjoining-Hangul Jamo and compatibility Hangul Jamo. This problem comes from allowing incorrect normalization form of compatibility Hangul Jamo and Hangul Symbol and also permitting to use conjoining-Hangul Jamo mixture with precomposed Hangul syllable in Unicode Hangul composing rule. It is caused by lack of consideration of old Hangul and/or insufficient understanding of Hangul code processing when writing specification for normalization forms in Unicode. Therefore on this paper, we study Hangul code in Unicode environment, specifically problems of normalization used for Web and XML, IDN in nowadays. Also we propose modification of Hangul normalization methods and Hangul composing rules for correct processing of Hangul normalization in Unicode.