• Journal of the Korean Society for Precision Engineering
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• v.24 no.6
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• pp.78-85
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• 2007

In this study, we performed finite element analysis for the design of a medical centrifuge and two-types of centrifuge were compared with each other. The types of centrifuge are 2-arm straight type and 3-arm type. Structural analysis was done with respect to the change of the rotational speed of the rotor of a centrifuge. When the rotor of centrifuge was rotated, the von Mises stress of 2-arm straight type-rotor was compared with the von Mises stress of 3-arm type. The margin of safety was estimated from the result. We found the critical speed of centrifuge from the campbell diagram by modal analysis.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.3
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• pp.223-228
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• 2015

This paper analyses the torque characteristics of the shoulder and elbow joints of a humanoid robot arm that is useful for an object lifting and transferring task instead of human beings. For the purpose, some typical human lifting behaviors are considered, and various simulations for lifting and transferring an object have been performed by employing a humanoid robot arm having a simple configuration of shoulder and elbow joints. Through the simulation, it is shown that the torque patterns and ranges of the shoulder and elbow joints required for such a humanoid lifting and transferring task can be found earlier in the design of a humanoid robot arm. As a result, this effort is useful for us to design an effective robot arm.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.207-212
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• 2001

The virtual reality technology has been developed as the computer and computer graphic technology are progressed. However it has still the limits of the use because of it costs a great for system construction. A virtual reality technology is the best application example to reduce time and cost of development in engineering. Actually, VR(Virtual reality) technology has given engineers the ability to design, test and evaluate engineering systems in a virtual environment. The objective of this paper is to construct the arm mounted display VR system by using 3 channel spherical screen and to show its capabilities of an engineering system development. This paper describes the development of arm mounted display VR system with 3 channel spherical screen system and the generation of 3 channel graphic modules. The arm mounted display VR system provides a highly economical efficiency because of it uses a popular computer system as a graphic server.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.8
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• pp.1133-1138
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• 2018

Lightweight Encryption Algorithm (LEA) is one of the most promising lightweight block cipher algorithm due to its high efficiency and security level. There are many works on the efficient LEA implementation. However, many works missed the secure application services where the IoT platforms perform secure communications between heterogeneous IoT platforms. In order to establish the secure communication channel between them, the encryption should be performed in the on-the-fly method. In this paper, we present the LEA implementation performing the on-the-fly method over the ARM Cortex-M3 processors. The general purpose registers are fully utilized to retain the required variables for the key scheduling and encryption operations and the rotation operation is optimized away by using the barrel-shifter technique. Since the on-the-fly method does not store the round keys, the RAM requirements are minimized. The implementation is evaluated over the ARM Cortex-M3 processor and it only requires 34 cycles/byte.

• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.308-315
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• 2015

The purpose of this study, using 3D printer, was tried to fabricate the short arm cast of mesh types that can be hygienic and adequate ventilation with a good radiography. We used the multi channel computed tomography (MDCT) with three dimension printer device of the fused deposition modeling (FDM) techniques. The material is used a degradable plastic (poly lactic acid, PLA). Three-dimensional images of the short arm were obtained in the MDCT and then make the three-dimensional volume rendering. Three dimension volume rendering of the short arm is implemented as a tomography obtained in MDCT. Virtual mesh type cast model was output as three-dimensional images is designed based on the three-dimensional images of the short arm. As a results, the cast output by 3D printers were able to obtain excellent radiograph images than the conventional cast, and then it can decreased itching with unsanitary, and can break down easily to the cast. In conclusion, the proposed virtual mesh type cast output by 3D printers could be used as a basis for future three-dimensional printing cast productions and offered help to patients in the real life.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.816-821
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• 2013

This paper proposes the design method of low-cost vector control system for induction motor using the ARM Cortex-M4 microcontroller. This MCU can be used instead of expensive DSP to control the home appliances such as refrigerator, air conditioner, washing machine and so on. This paper explains the major features of Cortex-M4 for motor control and how to realize a vector-controlled inverter using it. The developed system is applied to 3-phase induction motor of 200[W] and experimental results show good performance similar to the system using TMS320F28335 DSP.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.3
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• pp.241-246
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• 2004

We have designed LED display system using ARM7TDMI processor and implemented hangul input and output. This system is easily extensible because controller board and LED matrix board were designed one module. Possible Input Methods of LED display system are PC, PDA and remote controller's wired and wireless communication. We have ported QT/Embedded 2.3.7 with touch panel Input at embedded board of Linux OS 2.4.18 and PXA255 Processor based. QT Application which we coded is able to input displaying text using ethernet communication on embedded system. Many of indicating text data is able to be saved because only korean alphabet codes are stored for data which users want displaying.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10c
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• pp.391-393
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• 2002

KGDB는 리눅스 커널을 위한 소스 레벨 디버거로서, GDB와 함께 동작하여 커널 개발자가 리눅스 커널을 응용 프로그램처럼 디버깅 할 수 있는 기능을 제공한다. 현재 KGDB는 X86 계열의 하드웨어를 위한 리눅스에 오픈 프로젝트로서 커널 버전 2.4.18 까지 개발되어있다. 본 논문에서는 X86 용 리눅스만을 위한 KGDB를 확장하여, 내장형 시스템에 널리 사용되는 ARM 프로세서 기반의 하드웨어에서 Linux 커널을 개발할 때에도 KGDB를 이용할 수 있도록 프로세서 의존적인 부분을 구현하고, 이를 커널에 통합하여 삼성에서 개발된 ARM920T 기반의 S3C2400 보드에서 동작실험을 하였다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.3
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• pp.86-91
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• 2012

Door effort was calculated for a new door checker with torsion bar spring and integrated checker case by FE analysis. A hybrid checker arm which has peaks and valleys only on the upper surface was adopted to reduce noise in operation and make operation with more distinctive steps. The checker arm was modeled using shell elements to estimate both the longitudinal and the lateral resistance force by checker arm. By combining the checker arm resistance force obtained from analysis and the door self-closing force by the theoretical calculation, door effort was predicted to show the good correlation with test results. In addition the unrolling effect of roller model was investigated and a new roller type for more smooth rolling was studied.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.167-170
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• 2001

본 논문에서는 미국에서 고 선명(High Definition) TV를 위한 오디오 표준인 ATSC에 의해서 채택되고, DVD의 오디오 코덱으로 널리 채택된 Dolby AC-3 복호화기를 고정 소수점으로 변환한 후, ARM929T를 기반으로 실시간 구현하였다. 실시간 구현에 사용된 ARM920T 는 저전력 소비형 32-비트 고정 소수점 RISC 구조이며, 명령어 Cache 와 데이터 Cache, MMU(Memory Management Unit)로 구성되어 있다. 그리고 200MIPS 의 성능을 가지고 있어, 음성/오디오, 통신, 디지털 셀룰라폰에 적용할 수 있고, ASIC 화 할 수 있는 장점을 가지고 있다. 구현된 AC-3 복호화기는 약 67MIPS(6 채널, 640kbps, 48KHz)의 복잡도를 나타내며, 사용된 메모리양은 프로그램 ROM 23.3K Bytes, 데이터 ROM(table) 4.62K Bytes 및 RAM 45K Bytes 이다. 구현된 AC-3 복호화기는 Dolby사에서 제공하는 40 개의 test 벡터들을 bit-exact하게 통과하였다.