• Current Optics and Photonics
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• v.3 no.6
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• pp.531-540
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• 2019

Spectral Amplitude Coding Optical Code Division Multiple Access (SAC OCDMA) is an advanced technique in asynchronous environments. This paper proposes design and implementation of a novel quantum logic gate (QLG) code, with code construction algorithm generated without following any code mapping procedures for SAC system. The proposed code has a unitary matrices property with maximum overlap of one chip for various clients and no overlaps in spectra for the rest of the subscribers. Results indicate that a single algorithm produces the same length increment for codes with weight greater than two and follows the same signal to noise ratio (SNR) and bit error rate (BER) calculations for a higher number of users. This paper further examines the performance of a QLG code based SAC-OCDMA system with NAND and direct detection techniques. BER analysis was carried out for the proposed code and results were compared with existing MDW, RD and GMP codes. We demonstrate that the QLG code based system performs better in terms of cardinality, which is followed by improved BER. Numerical analysis reveals that for error free transmission (10^-9), the suggested code supports approximately 170 users with code weight 4. Our results also conclude that the proposed code provides improvement in the code construction, cross-correlation and minimization of noises.

• Proceedings of the Korean Reliability Society Conference
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• 2000.11a
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• pp.87-95
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• 2000

The testing product is the HSU(Hydrostatic Steering Unit) installed in the armored vehicle which has the compact structure of assembly with hydraulic pump, hydraulic motor, and several hydraulic valves. There are no assesment testing code for HSU within a country because the testing code for HUS is not involved in the technical concert from USA. Therefore the testing code is developed by the dynamic analysis of the armored vehicle. By the developed testing code, the test equipment is designed, manufactured, and used to apply the assesment test.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.406-408
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• 2005

A passive Optical Network (PON) is famous for the most cost-efficient solution among the optical networks. This is because there is no active device between a central office and subscribers. A wavelength division multiplexing (WDM) offers each subscriber to feel unlimited bandwidth. A WDM-PON, however, has a cost problem that WDM-PON is used commercially. To solve this trouble, it is surveyed that a Sub-Carrier Multiplexing (SCM) used in a WDM-PON increases the number of subscribers. The performance of WDM/SCM-PON varies with various noises. The several FEC Codes can reduce the effects of noise and improve the performance of the system. Thus, Choosing a suitable FEC code is important work. This paper describes that a Reed-Solomon (RS) code is the most suitable code for WDM/SCM-PON at the object of 100 Mbps and $10^{-9}$ BER

• Journal of the Korean Institute of Rural Architecture
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• v.24 no.2
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• pp.29-36
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• 2022

This study analyzed the effects of building and greenhouse structural code on the structural design and the greenhouse construction cost. The over-design possibility of greenhouse was analyzed when building structural code was applied using standard smart greenhouse drawings. The possibility of decrease in greenhouse construction cost was investigated if the currently applied building structural code was replaced with greenhouse structural code. As a result of comparing the member sizes with the standard drawings, building structural code was designed with 13%~74% more steel than greenhouse structural code. When building construction estimate was replaced with greenhouse construction estimate, it was possible to reduce the total construction cost of the glass greenhouse by 17% and that of the vinyl greenhouse by 14%. Since there is no standard construction estimate suitable for greenhouses, the wage unit price is set excessively, and the construction cost of the smart greenhouse is increasing. In conclusion, it is necessary to establish greenhouse structural code and greenhouse construction estimate to lower the greenhouse construction cost.

• Journal of Mechanical Science and Technology
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• v.15 no.8
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• pp.1196-1204
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• 2001

The effects of EGR(Exhaust Gas Recirculation) on heavy-duty diesel engine performance, NO and soot emissions were numerically investigated using the modified KIVA-3V code. For the fuel spray, the atomization model based on the linear stability analysis and spray wall impingement model were developed for the KIVA-3V code. The Zeldovich mechanism for the formation of nitric oxide and the soot model suggested by Hiroyasu et al. were used to predict the diesel emissions. In this paper, the computational results of fuel spray, cylinder pressure, and emissions were compared with experimental data, and the optimum EGR rates were sought from the NO and soot emissions trade-off. The results showed that the EGR is effective in suppressing NO but the soot emission was increased considerably by EGR. Using cooled EGR, soot emission could be enhanced without worsening of NO.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9C
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• pp.721-728
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• 2010

CAMC (constant amplitude multi-code) has a better performance of error correction in iterative decoding than SPCPC (single parity check product code). CAMC benefits from a processing gain since it belongs to a spread spectrum signal. We show that the processing gain enhances the performance of CAMC. Additional correction of bit errors is achieved in the de-spreading of iteratively decoded signal. If the number of errors which survived the iterative decoding is less than or equal to ($\sqrt{N}/2-1$), all of the bit errors are removed after the de-spreading. We also propose a stopping criterion in the iterative decoding, which is based on the histogram of EI (extrinsic information). The initial values of EI are randomly distributed, and then they converge to ($-E_{max}$) or ($+E_{max}$) over the iterations. The strength of the convergence reflects how successfully error correction process is performed. Experimental results show that the proposed method achieves a gain of 0.2 dB in Eb/No.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.10a
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• pp.85-90
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• 1995

A characteristic transport theory code CRX is developed and tested for cell and assembly calculations. Since the characteristic method treats explicitly (analytically) the streaming portion of the transport equation, CRX treats strong absorbers well and has no practical limitations placed on the geometry of the problem. To test the code, it was applied to three benchmark problems which consist of complex meshes and compared with other codes.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.591-594
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• 2008

Currently RFID code systems are classified into ISO, EPC, uCode, KKR code, Mobile RFID code, and etc. According to RFID code systems, RFID system is changed. For various RFID code systems, it's difficult to make it to the network and permanence of RFID business. And the existing system isn't add new RFID code systems to RFID system, and change it efficiently. This paper is proposed to a system of Multi RFID code Identification Translation using Ontology. This system is able to identify code data from RFID reader using ontology build into the identifier info and translation info of RFID code systems, and translate to URN data. Therefore in case of extending and changing RFID code systems, we can add and change the identifier info and translation info of RFID code systems in ontology.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.127-133
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• 2003

NSD(No Spin Differential) has been developed fer a military truck. A benchmarking study for USA and Russian NSD has been carried out. Axiomatic approach has been applied for improving the design. A test code for NSB has been developed and applied to the developed sample. In the test results of comparing the developed sample with the USA imported sample, three major characteristics-the noise, mobility and steerability - are in the range of the intended target. A practical process for the evolution design is proposed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.1A
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• pp.41-48
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• 2011

This paper proposes an efficient code acquisition scheme for direct-sequence spread spectrum (DSSS) based real-time locating systems (RTLS). The proposed scheme employs multiple bit integration to significantly decrease false alarms when no packet signal is transmitted and increase the detection probability when the RTLS tags are excited. The performance of the proposed code acquisition scheme is analyzed and numerically evaluated, and compared with those of single-dwell and traditional double-dwell code acquisition schemes. The simulation results show that the proposed multiple-bit integration scheme outperforms single-dwell and double-dwell schemes.