• International Journal of Highway Engineering
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• v.13 no.4
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• pp.123-132
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• 2011

The purpose of this study is to calculate and propose rational multi-lane loading factors for bridge design considering the probability of simultaneous truck passing in adjacent lanes and real truck weights. The probability of simultaneous truck passing is calculated by analyzing video image taken at various locations in highways and national roads. Weigh-In-Motion system data at two locations are used, which is combined with the probability of multiple presence to calculate the multi-lane loading factors for typical 2 lane and 5 lane bridges. Statistical properties of multi-lane loading factors are also calculated assuming that locations for video images and WIM data represent the overall traffic condition in the country. Results are compared with various design codes in the world and they show that the values are between the current Korea Bridge Design Code and AASHTO LRFD specification or Eurocode and are similar to Canadian Code.

• Journal of the Korea Society of Computer and Information
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• v.12 no.1 s.45
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• pp.155-160
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• 2007

Because output of multi-code CDMA system adapted high speed data transmission becoming multi-level system use linear amplifier in output stage and complex output signal. Therefore, Multi-Code CDMA system has shortcoming of high price, high complexity etc.. Binary CDMA technology that allow fetters in existing CDMA technology to supplement this shortcoming proposed. In binary CDMA system When correlator process high speed data, bottle-neck phenomenon is happened on synchronization acquisition process, it is very important parameter. Because existent correlator must there be advantage that power consumption is small but flow addition of several stages to receive correlation's value, the processing speed has disadvantage because the operation amount is much. Therefore in this paper, proposed correlator has characteristic such as data is able to high speed processing, chip area is independent and power consumption is constant in structure in binary CDMA system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.589-592
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• 2016

The period of the previous multi-core could be helped to improve program performance, based on the development of the hardware. However, one of the core performance enhancements for this encounter limitations and become the common way of multi-core with multiple cores. Modern programming concurrency that improves the conventional method for using threads of the kernel level in order to use the multi-core come to the fore. Using modern lightweight thread concurrency programming is to optimize the benefits of multi-core. Also sharing the absence of available data that can change is a major consideration when writing concurrent code. This paper describes the key considerations when creating a discussion concurrent code, and these issues are being supported in any way in the language of one 'go' of technologies that support the modern concurrency, and even how to write better code concurrency.

• Journal of the Korean Society of Systems Engineering
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• v.18 no.2
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• pp.58-74
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• 2022

Deterministic accident analysis plays a central role in the nuclear power plant (NPP) safety evaluation and licensing process. Traditionally the conservative approach opted for the point kinetics model, expressing the reactor core parameters in the form of reactivity and power tables. However, with the current advances in computational power, high fidelity multi-physics simulations using real-time code coupling, can provide more detailed core behavior and hence more realistic plant's response. This is particularly relevant for transients where the core is undergoing reactivity anomalies and uneven power distributions with strong feedback mechanisms, such as reactivity initiated accidents (RIAs). This work addresses a RIA, specifically a control element assembly (CEA) withdrawal at power, using the multi-physics analysis tool RELAP5/MOD 3.4/3DKIN. The thermal-hydraulics (TH) code, RELAP5, is internally coupled with the nodal kinetics (NK) code, 3DKIN, and both codes exchange relevant data to model the nuclear power plant (NPP) response as the CEA is withdrawn from the core. The coupled model is more representative of the complex interactions between the thermal-hydraulics and neutronics; therefore the results obtained using a multi-physics simulation provide a larger safety margin and hence more operational flexibility compared to those of the point kinetics model reported in the safety analysis report for APR1400. The systems engineering approach is used to guide the development of the work ensuring a systematic and more efficient execution.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.11B
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• pp.1864-1871
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• 2000

본 논문에서는 차세대 무선 통신 시스템에 적용이 가능한 새로운 FEC(Forward Error Correction) 부호화 방법으로 MLC(Multi-Level Convolutional) 부호화 방식을 제안한다. 차세대 무선통신서비스는 음성, 데이터, 영상 등 많은 종류의 서비스를 함으로써 데이터의 처리속도가 빠른 시스템이 요구된다. 데이터 처리시간을 단축시키기 위한 방법으로 다중 레벨을 이용하여 부호어를 만들어 내는 방식의 부호화 시스템을 설계하였다. MLC는 부호 처리시간을 단축시킬 뿐만 아니라 다양한 알고리즘을 이용해 부호어를 만들어 낼 수 있다는 특징을 가지게 된다. 모의실험은 MLC 코드의 두 가지 방법, Modulo- operation 방식과 Galois Field-Operation 방식을 이용하여 수행하였다. 또한 모의실험을 통하여 (s=2, T=2)인 경우가 MLC 부호기의 최적 연결다항식임을 알았다.

• Proceedings of the IEEK Conference
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• 2000.06d
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• pp.92-97
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• 2000

An AMR(Adaptive Multi-Rate) speech coding algorithm has been adopted as a standard speech codec for IMT-2000. It is based on the algebraic CELP, and consists of eight speech coding modes having the bit rate from 4.75 kbit/s to 12.2 kbit/s. It also contains the VAD(Voice Activity Detector), SCR (Source Controlled Rate) operation, and error concealment scheme for robustness in a radio channel. The bit rate of AMR is changed on a frame basis depending on the channel condition. In this paper, we introduced AMR speech coding algorithm and performed the real-time implementation using TMS320C6201, i.e., a Texas Instrument's fixed-point DSP. With the ANSI C source code released from ETSI and 3GPP, we convert and optimize the program to make it run in real time using the C compiler and assembly language. It is verified that the decoded result of the implemented speech codec on the DSP is identical with the PC simulation result using ANSI C code for test sequences. Also, actual sound input/output test using microphone and speaker demonstrates its proper real-time operation without distortions or delays.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.2
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• pp.80-86
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• 2002

Previous method of computer simulation to predict the dynamic response of a vehicle has been based on the assumption that vehicle structure is rigid. If the flexibility of the vehicle structure becomes too large to ignore, rigid body assumption will no longer give good estimation of the dynamic characteristics. Therefore, in order to predict more precise vehicle dynamic characteristics, flexible multi-body dynamic analysis of a vehicle is necessary. This paper investigates dynamic characteristics of vehicle systems with flexible frames numerically. Joint reaction forces, vertical accelerations, pitch accelerations are analyzed for the vehicle systems with various flexible frames using multi-body dynamic analysis code and finite element analysis code.

• ETRI Journal
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• v.39 no.3
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• pp.319-325
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• 2017

The decoding process of a quasi-cyclic low-density parity check code requires a unique type of rotator. These rotators, called multi-size cyclic-shifters (MSCSs), rotate input data with various sizes, where the size is the amount of data to be rotated. This paper proposes a low-complexity MSCS structure for the case when the sizes have a nontrivial common divisor. By combining the strong points of two previous structures, the proposed structure achieves the smallest area. The experimental results show that the area reduction was more than 14.7% when the proposed structure was applied to IEEE 802.16e as an example.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.6
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• pp.719-727
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• 2016

This paper proposes a unified medium access control (MAC) design methodology and presents the implementation of the IEEE 802.11ac down-link multi-user multi-input and multi-output wireless local area network MAC using the proposed design methodology. The proposed methodology employs unified code for both network simulation and system implementation. Because the unified code closely relates these two processes, the performance of the implemented MAC system can be estimated before implementation. The MAC architecture for an access point implemented using the proposed design methodology is verified on an ARM-based platform, and it is applied to a 65 nm CMOS library.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9A
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• pp.1058-1066
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• 2004

This paper proposes the acquisition system using the multiple antennas in DS-CDMA system. The conventional acquisition schemes using multiple antennas are the methods to utilize the multi-antenna combining and the fixed multi-beam forming of a serial acquisition. Then, this paper proposes the hybrid acquisition scheme using the fixed multi-beam forming. The numerical results show the performance comparison of two acquisition schemes in terms of the acquisition time ill the multipath Rayleigh fading channel.