• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.9
• /
• pp.1562-1570
• /
• 2003

The prediction of the inelastic behavior of the structure is an essential part of reliability assessment procedure, because most of the failures are induced by the inelastic deformation, such as creep and plastic deformation. During decades, there has been much progress in understanding of the inelastic behavior of the materials and a lot of inelastic constitutive equations have been developed. The complexity of these constitutive equations generally requires a stable and accurate numerical method. The radial return mapping is one of the most robust integration scheme currently used. Nonlinear kinematic hardening model of Armstrong-Fredrick type has recovery term and the direction of kinematic hardening increment is not parallel to that of plastic strain increment. In this case, The conventional radial return mapping method cannot be applied directly. In this investigation, we expanded the radial return mapping method to consider the nonlinear kinematic hardening model and implemented this integration scheme into ABAQUS by means of UMAT subroutine. The solution of the non-linear system of algebraic equations arising from time discretization with the generalized midpoint rule is determined using Newton method and bisection method. Using dynamic yield condition derived from linearization of flow rule, the integration scheme for elastoplastic and viscoplastic constitutive model was unified. Several numerical examples are considered to demonstrate the efficiency and applicability of the present method.

• The Journal of Bigdata
• /
• v.5 no.1
• /
• pp.181-188
• /
• 2020

As the size of the airport terminal grows in line with the rapid growth of aviation passengers, the advanced baggage handling system that combines various data technologies has become an essential element in order to handle the baggage carried by passengers swiftly and accurately. Therefore, this study introduces the method of analyzing the baggage handling capacity of domestic airports through the latest data analysis methodology from the process point of view to advance the operation of the airport BHS and the main points based on event log data. By presenting an accurate load prediction method, it can lead to advanced BHS operation strategies in the future, such as the preemptive arrangement of resources and optimization of flight-carrousel scheduling. The data used in the analysis utilized the APIs that can be obtained by searching for "Korea Airports Corporation" in the public data portal. As a result of applying the method to the domestic airport BHS simulation model, it was possible to confirm a high level of predictive performance.

• Journal of the Microelectronics and Packaging Society
• /
• v.9 no.1
• /
• pp.35-41
• /
• 2002

Flip-chip interconnection that uses solder bump is an essential technology to improve the performance of micro-electronics which require higher working speed, higher density, and smaller size. In this paper, the shear strength of Cr/Cr-Cu/Cu UBM structure of the high-melting solder bump and that of low-melting solder bump after aging is evaluated. Observe intermetallic compound and bump joint condition at the interface between solder and UBM by SEM and TEM. And analyze the shear load concentrated to bump applying finite element analysis. As a result of experiment, the maximum shear strength of Sn-97wt%Pb which was treated 900 hrs aging has been decreased as 25% and Sn-37wt%Pb sample has been decreased as 20%. By the aging process, the growth of $Cu_6/Sn_5$ and $Cu_3Sn$ is ascertained. And the tendency of crack path movement that is interior of a solder to intermetallic compound interface is found.

• The Research Journal of the Costume Culture
• /
• v.19 no.4
• /
• pp.876-887
• /
• 2011

The purpose of this study was to determine the fundamental foot measurement data that is essential for a shoes size system of women in their 20~30s according to a survey of Korean hand-made shoes companies. This research on the current situation of shoes companies was done by interviewing and surveying employees of these companies. The subjects for this study were 407 women in their 20s~30s who lived in a metropolitan area, and who wanted to enhance their foot health and prevent injury with a proper shoes size system. They were measured with the 3D scan method in use of 6th Size Korea. The result of this study showed that there is considerable dissatisfaction related to women's shoes and the current foot size system using foot length. The Korean hand-made shoes companies assessed here did not use the KS system, but they recognized the necessity of measuring the foot width and circumference, understanding that doing so properly can decrease the return and repair rate. And current target age for shoes bye the hand-made shoes companies was reported to be approximately 5 years. There were significant results according to ANOVA, factor and cluster analyses according to the age range pertaining to the foot length, circumference and height. Each element was significantly correlated with user's satisfaction. There were 5 factors and 3 clusters represented, and foot circumstance and width were as important as foot length with a range of 5 years.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.1 s.45
• /
• pp.117-126
• /
• 2007

Web Forensics algorithm used to an extraction of technical Web Forensics data to be adopted to proof data regarding a crime cyber a computer at data of a great number of log History is an essential element. Propose Web Forensics algorithm, and design at these papers, and try to implement in a Web server system of an actual company. And make the Web dispatch Loging system configuration experiment that applied integrity regarding Web log History information or authentication regarding an information source. Design Web Forensics algorithm and the Flow which used for Web log History analyses at server of e-mail, webmail, HTTP (Web BBs. Blog etc.), FTP, Telnet and messengers (MSN, NateOn, Yahoo, DaumTouch, BuddyBuddy, MsLee, AOL, SoftMe) of a company, and implement through coding. Therefore have a purpose of these Paper to will contribute in scientific technical development regarding a crime cyber a computer through Web Forensics.

• Journal of the Korean Society for Railway
• /
• v.19 no.2
• /
• pp.109-116
• /
• 2016

The market share of high-speed railway vehicles is increasing across the world. A high-performance impact energy absorption factor is essential to satisfy the safety standards of railway vehicles. A deformed tube assembly is a typical energy absorption factor in railway vehicles. The tube assembly comprises a deformed tube and a press-fitting punch, its performance depends on the absorption energy characteristics in the plastic zone of the tube. In this study, a deformed tube assembly of a railway vehicle is designed that can absorb a maximum impact energy of 200kJ under plastic deformation. Slab method and finite element analysis are used to estimate the reaction force of the punch in the initial stage, the performance of the designed tube assembly is confirmed experimentally.

• Convergence Security Journal
• /
• v.12 no.3
• /
• pp.75-83
• /
• 2012

Recent science technology research network moves to establish logical private network among specific research groups such as high energy physics and climate, requiring to implement private network by group for each purpose. Up to now, national research networks such as KREONET service high capacity logical private networks. Therefore standardized configuration and management scheme is essential for the deployment of logical private network. In this study, we propose the core service element and protocols for the logical networks over Layer 2 networks. We also propose system architecture that make monitoring and management easier. After that we design and implement monitoring map for logical network based on scheme. For this purpose, we also propose the description system for logical research network to provide data such as operation information, formation information, performance information and failure information of network infrastructure resource.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.11A
• /
• pp.1147-1158
• /
• 2006

Clustering algorithm is an essential element to implement a hierarchical routing protocol, especially for a large-scale wireless sensor network. In this paper, we propose a new type of energy-efficient clustering algorithm, which maximizes the physical distance between cluster head and gateway by a neighbor node discovery mechanism. Furthermore, a slave/master patching scheme is introduced as a useful means of further improving the energy-efficiency. It has been shown that the number of cluster heads can be reduced by as many as 21% as compared with the existing clustering algorithms.

• Journal of the Korean Society for Library and Information Science
• /
• v.36 no.1
• /
• pp.297-320
• /
• 2002

The purpose of this study is to identify theoretical basis of information literacy program in the Korea. Nine Information Literacy Program were compared with ACRL Information Standards. The result of this study is as follows: (1) The identification of information needed was included in the programs that emphasized a thesis or topic statement and formulated question, critical thinking, information technology. (2) Most programs contained mainly potential sources for information. (3) Each programs had element of Information access strategy and skills that explained to OPAC, Indexes and Abstracts, On-line retrievals. (4) Implements the search strategy using various formats was essential elements in the programs. (5) Evaluation and synthesis was included in the programs, partially evaluation for information process and satisfaction was included. (6) The writing skills for termpaper. quotations and oral presentations are important elements of information use in the programs, however. those programs didn't contain enough the ethical and legal uses of information with respect to the standard.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.28 no.4
• /
• pp.809-826
• /
• 2018

The entropy evaluation method for noise sources is one of the evaluation methods for the random number generator that is the essential element of modern cryptographic systems and cryptographic modules. The primary entropy evaluation methods outside of the country are more suitable to apply to hardware noise sources than software noise sources, and there is a difficulty in quantitative evaluation of entropy by software noise source. In this paper, we propose an entropy evaluation method that is suitable for software noise sources, considering characteristics of software noise sources. We select time-dependent noise sources that are software noise sources of Windows OS, and the heuristic analysis and experimental analysis are performed considering the characteristics of each time-dependent noise source. Based on these analyses, we propose an entropy harvest method from the noise source and the min-entropy estimation method as the entropy evaluation method for time-dependent noise sources. We also show how to use our entropy evaluation method in the Conditioning Component described in SP 800-90B of NIST(USA).