• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1010-1015
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• 2005

Recently, advancements in railway system and IT have enabled automatic or driverless train. Futhermore, developed countries have been tried to develope unmaned operation system for railway system. To apply manless operation in railway system, development of simulator for manless operation is required. The advantage of the simulator is in that it makes it possible to analyze the systems behavior. In this paper, we define system requirements and functionalities, and establish the system scenarios to handle the various accidents/faults in manless operation environment. We expects the proposed system requirements and system scenarios will playa key role to establish the man less operation in advanced urban transit system.

• Journal of the Korean Dietetic Association
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• v.15 no.4
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• pp.364-382
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• 2009

The purposes of this study were to develop the standard indicators to evaluate the food and nutrition systems in hospitals and to test the validity of those items scientifically. The results were as follows: First, the conceptual validity was examined with recognition degrees of importance from the hospital nutrition department managers. All of the hospital nutrition department's operation evaluation standards and the indicators' conceptual validity tested were in the range of 3.71~4.93 out of 5.0, and the mean score was 4.36. Therefore, the conceptual validity was verified. Second, to verify the factor validity of the items of the standards and indicators for the hospital nutrition department's operation evaluation, the standards and indicators were analyzed as key-factors. Key-factor analysis after vertical rotation showed that four factors appeared and were composed of (a) facilities management, (b) sanitation management, (c) operation & foodservice management, and (d) nutrition management. Third, the reliability of the standards and indicators for the hospital nutrition department's operation evaluation was analyzed and resulted in a score of 0.98, which showed good internal consistency. Fourth, the discriminative power of each item of the standards for the hospital nutrition department's operation evaluation was tested by checking the differences between groups with first quartile and forth quartile of total evaluation scores. The indicators having low distinction power were modified into obligatory items or eliminated for better differentiation.

• Proceedings of the IEEK Conference
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• 2004.06b
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• pp.529-532
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• 2004

The ECC(Elliptic Curve Cryptogrphics), one of the representative Public Key encryption algorithms, is used in Digital Signature, Encryption, Decryption and Key exchange etc. The key operation of an Elliptic curve cryptosystem is a scalar multiplication, hence the design of a scalar multiplier is the core of this paper. Although an Integer operation is computed in infinite field, the scalar multiplication is computed in finite field through adding points on Elliptic curve. In this paper, we implemented scalar multiplier in Elliptic curve based on the finite field GF($2^{163}$). And we verified it on the Embedded digital system using Xilinx FPGA connected to an EISC MCU. If my design is made as a chip, the performance of scalar multiplier applied to Samsung $0.35 {\mu}m$ Phantom Cell Library is expected to process at the rate of 8kbps and satisfy to make up an encryption processor for the Embedded digital doorphone.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.2
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• pp.738-756
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• 2020

The modular multiplication is the key module of public-key cryptosystems such as RSA (Rivest-Shamir-Adleman) and ECC (Elliptic Curve Cryptography). However, the efficiency of the modular multiplication, especially the modular square, is very low. In order to reduce their operation cycles and power consumption, and improve the efficiency of the public-key cryptosystems, a dual-field efficient FIPS (Finely Integrated Product Scanning) modular multiplication algorithm is proposed. The algorithm makes a full use of the correlation of the data in the case of equal operands so as to avoid some redundant operations. The experimental results show that the operation speed of the modular square is increased by 23.8% compared to the traditional algorithm after the multiplication and addition operations are reduced about (s² - s) / 2, and the read operations are reduced about s² - s, where s = n / 32 for n-bit operands. In addition, since the algorithm supports the length scalable and dual-field modular multiplication, distinct applications focused on performance or cost could be satisfied by adjusting the relevant parameters.

• Journal of Korea Multimedia Society
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• v.21 no.8
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• pp.897-908
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• 2018

In this paper, we propose a security framework for a cluster drones network using the MAVLink (Micro Air Vehicle Link) application protocol based on FANET (Flying Ad-hoc Network), which is composed of ad-hoc networks with multiple drones for IoT services such as remote sensing or disaster monitoring. Here, the drones belonging to the cluster construct a FANET network acting as WTRP (Wireless Token Ring Protocol) MAC protocol. Under this network environment, we propose an efficient algorithm applying the Lightweight Encryption Algorithm (LEA) to the CTR (Counter) operation mode of WPA2 (WiFi Protected Access 2) to encrypt the transmitted data through the MAVLink application. And we study how to apply LEA based on CBC (Cipher Block Chaining) operation mode used in WPA2 for message security tag generation. In addition, a modified Diffie-Hellman key exchange method is approached to generate a new key used for encryption and security tag generation. The proposed method and similar methods are compared and analyzed in terms of efficiency.

• Journal of the Ergonomics Society of Korea
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• v.17 no.3
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• pp.61-70
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• 1998

The purpose of this paper is to evaluate the input methods of the numeric keypads that are widely used in various types of consumer and industrial electronic products. Three methods to enter numerals using keypads were compared: (1) Machine Intelligence, (2) + 100 key, and (3) Enter key input methods. Experiments were conducted to compare these three input methods for the channel selection of TV. Experimental prototypes which simulate TV user interfaces were developed using $RAPID^{TM}$ for usability testings. In the experiment, data on subject performance such as completion time, operational errors, and user interaction were collected through auto-logging method and video recording. After each test session, subjective preference was also asked using a questionnaire. In order to analyze the type of operation errors and the error causation, operation sequences were analyzed from the collected data. The Enter key input method showed better performance than other input methods. Based on these results. we can conclude that the input method using numeric keypads should be compatible with generic number counting(to input ch 7, it would be better to input 7 directly than to input 07 or 007) and should switch the channel as quickly as possible. This conclusion can be applied to the design of user interfaces which require numeral inputs.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1071-1074
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• 2005

The ECC(Elliptic Curve Cryptogrphics), one of the representative Public Key encryption algorithms, is used in Digital Signature, Encryption, Decryption and Key exchange etc. The key operation of an Elliptic curve cryptosystem is a scalar multiplication, hence the design of a scalar multiplier is the core of this paper. Although an Integer operation is computed in infinite field, the scalar multiplication is computed in finite field through adding points on Elliptic curve. In this paper, we implemented scalar multiplier in Elliptic curve based on the finite field $GF(2^{163})$. And we verified it on the Embedded digital system using Xilinx FPGA connected to an EISC MCU(Agent 2000). If my design is made as a chip, the performance of scalar multiplier applied to Samsung $0.35\;{\mu}m$ Phantom Cell Library is expected to process at the rate of 8kbps and satisfy to make up an encryption processor for the Embedded digital information home system.

• Journal of Korea Multimedia Society
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• v.25 no.8
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• pp.983-990
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• 2022

In this paper, we implemented a hierarchical encryption system using two-step phase-shifting digital holography(PSDH) technology based on XOR and scramble operations. The proposed encryption system is a system that authenticates access through the issuance of an encryption key for access to individual laboratories, department offices, and universities. In the encryption process, we proposed a double encryption method using XOR and scramble operation with digital technology and two-step phase-shifting digital holography with optical technology. In the two-step PSDH process, an new method of determining the reference wave intensity without measuring it by using random common object image gererated from digital encryption process was also proposed. In the decryption process, the process is performed in the reverse order of encryption process. And only when the various key information used in the encryption process is correct, the encrypted information can be decrypted, so that the user can access the desired place. That is, there is a feature that can hierarchically control the space that can be accessed according to the type of key issued in the proposed encryption system. Through the computer simulation, the feasibility of the proposed hierarchical encryption system was confirmed.

• Journal of the Korean Society for Railway
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• v.17 no.4
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• pp.297-306
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• 2014

This paper analyzes Japan's consignment management of the Chosun Railway to the South Manchuria Railway. While Chosun Railway was entrusted, its management style differed significantly from that of Japan's direct management. After eight years of trust management, the direct management of Chosun Railway was returned to Japan. This of beyond border trust management is very rare. In addition, the management of Chosun Railway by South Manchuria Railway, which had an operation style similar to that of a private company, led to changes in Chosun Railway. This research analyzes the four key traits of South Manchuria Railway's consigned management. The first key trait is the initial Korean infrastructure and operation separation model. The second key trait is the international transportation and administration segregation. The third key trait is that it expanded the railway related businesses and led to the establishment of private railway companies. The fourth key trait is that the continental linked transportation was activated. Through analyses, it would be to create a comparative study of the resulting East Asian countries' operations. Furthermore, this research will in investigating the nature of Chosun Railway.

• Geomechanics and Engineering
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• v.35 no.5
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• pp.525-538
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• 2023

The development of a city is closely linked to the construction and operation of its subway system. However, constructing a new subway tunnel under an existing station is an extremely complex task, and the deformation characteristics and mechanical behavior of the new subway tunnel during the excavation process can greatly impact the normal operation of the existing station. Although the previous studies about the case of underpass engineering have been carried out, there is limited research on the condition of a newly-built subway tunnel that closely undercrossing an existing station with zero distance between them. Therefore, this study analyzes the deformation law and mechanical behavior characteristics of the preliminary lining of the underpass tunnel during the excavation process based on the real engineering case of Chengdu Metro Line 8. This study also makes an in-depth comparison of the influence of different excavation methods on this issue. Finally, the accuracy of numerical simulation is verified by comparing it with on-site result. The results indicate that the maximum bending moment mainly occurs at the floor slab of the preliminary lining, while that of the ceiling is small. The stress state at the ceiling position is less affected by the construction process of the pilot tunnel. Compared to the all-in-one excavation method, although the process of partial excavation method is more complicated, the deformation of preliminary lining caused by it is basically less than the upper limit value of the standard, while that of the all-in-one excavation method is beyond standard requirements.