• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.13 no.4
• /
• pp.69-74
• /
• 2014

A waste gate valve (WGV) assembly for a gasoline turbocharger is typically manufactured by means of precision casting. In this study, however, it was newly manufactured in a more innovative way, metal injection molding (MIM) using Inconel 713C alloy, and its performance was tested in a 1.6L direct injection gasoline engine by a thermal shock durability test that lasted 300 hours, after which the results were compared to those of a precision-cast WGV assembly with regard to the engine intake boost pressure, turbine wheel speed, and transient intake pressure. It was found that the two WGV assemblies showed similar performance levels throughout the durability test.

• The Journal of the Acoustical Society of Korea
• /
• v.16 no.2
• /
• pp.80-88
• /
• 1997

In this paper, the implementation of audio/data processor using ETRI DSP to support analog mode in digital/analog dual mode mobile phone is presented. Audio/data processor performs the wideband data processing, audio signal processing, demodulation function, and data rate conversion when it is operated in analog mode. These functions are programmed in assembly language, and then loaded to ETRI DSP together with vocoder program for the digital mode operation. This is a very efficient implementation of the dual mode cellular phone ASIC since the vocoder for the digital mode and audio/data processor for the analog mode are programmed together in the same hardware.

• Proceedings of the Acoustical Society of Korea Conference
• /
• autumn
• /
• pp.23-26
• /
• 2000

본 논문에서는 국제 통신 표준화기구인 ITU-T에서 인터넷폰과 화상회의를 목적으로 채택된 G.723.1 음성 부호화 시스템을 TMS320C5409를 이용하여 전 과정을 어셈블리어로 실시간 구현하였다. 구현된 G.723.1 음성 부호화기는 6.3kbps 전송률일 때 인코더 25.75MIPS이고 디코더 1.99MIPS의 최대 복잡도를 나타내고, 5.3kbps 전송률일 때 인코더 17.69MIPS이고 디코더 1.9Ml PS의 최대 복잡도를 나타낸다. 사용된 메모리는 program ROM llkwords, data ROM(table) 9.45kwords, RAM 2.8kwords 정도이며, 실시간 처리된 출력음성은 C simulation결과와 같은 음질을 보였다. 구현된 G.723.1 음성 부호화기는 ITU-T에서 제공되는17개의 테스트 벡터를 모두bit-exact하게 통과하였다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.3
• /
• pp.802-807
• /
• 2010

The high efficient and cooling system is very important to the control panels of electrical distributors, and Industrial automated system including computer. Also, it can be used widely in various industrial systems such as industrial robots, numerically controlled machining center, and so on. The cooling method which flowing gasses were forced to circulate by compulsion was adapted in this study. then development of counter flow type of cooling system for effective panel cooling. In the present study, fin assembly was developed for this cooling system. As results, the developed system has the improvements of cooling performances and radiant heat ratio. Its increasing of airflow mass is about 20%, and radiation rate of heating is twice or more as high as the conventional system.

• Korean Journal of Materials Research
• /
• v.21 no.12
• /
• pp.650-654
• /
• 2011

In this paper, the effects of conventional and newly developed elastomer modified underfill materials on the mechanical shock reliability of BGA board assembly were studied for application in mobile electronics. The mechanical shock reliability was evaluated through a three point dynamic bending test proposed by Motorola. The thermal properties of the underfills were measured by a DSC machine. Through the DSC results, the curing condition of the underfills was selected. Two types of underfills showed similar curing behavior. During the dynamic bending reliability test, the strain of the PCB was step increased from 0.2% to 1.5% until the failure circuit was detected at a 50 kHz sampling rate. The dynamic bending reliability of BGA board assembly using elastomer modified underfill was found to be superior to that of conventional underfill. From mechanical and microstructure analyses, the disturbance of crack propagation by the presence of submicron elastomer particles was considered to be mainly responsible for that result rather than the shear strength or elastic modulus of underfill joint.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.26 no.10
• /
• pp.2008-2017
• /
• 2002

Joint structure of a transducer horn-holder assembly fur a wire bonder was examined through FEM contact analysis. A three dimensional modeling and analysis was carried out to survey the internal physics of this structure and to prove the accuracy of a computation compared to a measurement. After validation, a simple two dimensional model was built fur various parametric study considering the efficiency and speed of the computation. Several factors such as boundary conditions, a modeling boundary, mesh density and so on, were considered to obtain consistency with three dimensional analysis. An arc angle and a position of each holder boss were chosen as design parameters. A design of experiment was applied to find out an optimized design of the holder geometry. As a result, a guideline for holder boss design was suggested and main factors and their influence on stress concentration in the transducer horn were surveyed.

• Journal of Korea Multimedia Society
• /
• v.12 no.8
• /
• pp.1120-1127
• /
• 2009

The commensurate number of the attacks and infringement targeting a vulnerability of the game service has been increasing constantly, due to the dramatic growth and expansion of the impact of the game industry. However, there exist no subsequent researches for the differentiated technology, which is to prevent the reverse function of the game service. Therefore, in this study, we examined the current status of infringement toward online game services which are provided in the market currently and designed the proper technical measures for a manipulation of the game service which is the most vulnerable part. We have encrypted an execution file and decrypted it in real time process. Furthermore, we conducted debugging, disassemble, and prevented a its own memory dump, also concealed the information to overcome the module dependency to preclude a manipulation.

• Proceedings of the Korean Information Science Society Conference
• /
• 2010.06c
• /
• pp.554-559
• /
• 2010

자율무인잠수정은 탐사 목적에 따라 다양한 임무를 수행해야 하며, 임무에 따라 자율무인잠수정 행동의 유형과 순서는 달라질 수 있다. 그러나 대부분의 자율무인잠수정은 한정된 임무에 대하여 프로그램 내부에 고정된 행동 유형으로 동작하며, 다른 유형의 임무를 수행해야 할 경우에는 프로그램을 수정해야 하는 문제점이 있다. 따라서 본 연구에서는 자율무인잠수정이 수행할 수 있는 다양한 임무를 명시할 수 있는 임무 언어를 개발하였다. 이 임무 언어는 명령어의 실행 순서를 제어할 수 있는 제어문과 자율무인잠수정의 행동을 지정하거나 자율무인잠수정의 상태를 입출력 할 수 있는 명령어, 그리고 변수 정의를 제공하기 때문에, 사용자가 자율무인잠수정의 임무를 자유롭게 표현하는 것이 가능하다. 임무 언어로 작성된 임무 파일은 전용 어셈블러에 의해 이진 형식의 실행이미지로 변환된 후에, 자율무인잠수정 내장 소프트웨어 내부의 가상기계 기억장치에 적재되어 실행된다. 실행이미지를 가상기계에서 해석하고 실행하는데 필요한 시스템의 자원을 최소화하기 위하여 임무 언어는 자율무인잠수정의 임무를 표현하기 위한 필수적인 부분만을 고려하여 설계되었으며, 문법은 ARM v5 어셈블리와 유사한 형태이다. 개발된 임무 언어는 한국해양연구원에서 개발한 이심이100 자율무인잠수정에 적용되었으며, 이후 개발할 6,000m급의 이심이6000 자율무인잠수정에도 사용될 예정이다.

• Journal of the Korean Society of Industry Convergence
• /
• v.24 no.5
• /
• pp.581-587
• /
• 2021

In recent years, contamination of drinking water sources has emerged as a serious social problem, such as a large number of impurities in tap water or groundwater or the supply of suitable water due to rust of pipes. Although the government and public institutions are implementing various measures to protect water sources, they cannot improve water quality in a short period of time because of the enormous cost involved. Therefore, in recent years, preference has been given to a device that converts tap water, which is hard water, into soft water by installing a separate water softener at the faucet from which tap water is discharged. However, the existing filtration device has a problem that filtration performance is gradually lowered when impurities accumulate in the filter, requiring continuous filter replacement. In this study, the optimal design of the filter housing was performed to develop a water softener that can be washed when impurities accumulate on the filter inside the water softener connected to the faucet. For optimal design of the filter housing, fluid and fluid-structural interaction analysis were performed on the design pressure to determine the shape and thickness of the housing, and design review was performed through prototype.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.31 no.3
• /
• pp.423-431
• /
• 2021

SPECK and SIMON are lightweight block ciphers developed by NSA(National Security Agency), and SIMECK is a new lightweight block cipher that combines the advantages of SPECK and SIMON. In this paper, a large-capacity encryption using SPECK, SIMON, and SIMECK is implemented using a GPU with efficient parallel processing. CUDA library provided by NVIDIA was used, and performance was maximized by using CUDA assembly language PTX to eliminate unnecessary operations. When comparing the results of the simple CPU implementation and the implementation using the GPU, it was possible to perform large-scale encryption at a faster speed. In addition, when comparing the implementation using the C language and the implementation using the PTX when implementing the GPU, it was confirmed that the performance increased further when using the PTX.