• 한국통신학회논문지
• /
• 제32권8C호
• /
• pp.712-719
• /
• 2007

본 논문에서는 $4{\times}4$ 단위의 하다마드 변환을 이용한 새롭고 효과적인 움직임 예측 알고리즘을 제안한다. 하다마드 변환은 덧셈과 뺄셈으로만 이루어져 있기 때문에 고속 알고리즘에 적합하다는 장점이 있다. 제안하는 알고리즘은 세 단계로 이루어져 있다. 먼저 하다마드 DC(Direct Current) 계수를 이용하여 움직임 추정의 조기종결여부를 블록의 특성에 적응적으로 적용하고 이전 프레임의 움직임 벡터를 이용할지를 결정한 다음, 하다마드 AC(Alternating Current) 계수를 이용하여 영상의 복잡도를 구하여 정합 스캔 순서를 적응적으로 결정한다. 마지막으로 제안하는 알고리즘을 MVFAST와 PMVFAST 알고리즘에 적용했다. 모의 실험 결과 제안하는 알고리즘은 계산 속도와 PSNR(Peak Signal-to-Noise Ratio) 면에서 MVFAST와 PMVFAST 알고리즘에 비해 매우 효율적임을 나타냈다.

• Nuclear Engineering and Technology
• /
• 제34권5호
• /
• pp.494-501
• /
• 2002

Radioactive Corrosion Products (CRUD) which are generated by the neutron activation of general corrosion products at the nuclear power plant are the major source of occupational radiation exposure. Most of the CRUD has a characteristic of showing strong ferrimagnetisms. Along with the new development and production of permanent magnet (rare earth magnet) which generates much stronger magnetic field than the conventional magnet, new type of magnetic filter that can separate CRUD efficiently and eventually reduce radiation exposure of personnel at nuclear power plant is suggested. This separator consists of inner and outer magnet assemblies, coolant channel and container surrounding the outer magnet assembly. The rotational motion of the inner and outer permanent magnet assemblies surrounding the coolant channel by driving motor system produces moving alternating magnetic fields in the coolant channel. The CRUD can be separated from the coolant by the moving alternating magnetic field. This study describes the results of preliminary experiment performed with the different flow rates of coolant and rotation velocities of magnet assemblies. This new magnetic filter shows better performance results of filtering the magnetite at coolant (water). How rates, rotating velocities of magnet assemblies and particle sizes turn out to be very important design parameters.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
• /
• pp.1380-1383
• /
• 1996

This paper presents a recoil and counter recoil(R&CR) motion measurement method using linear variable differential transformers(LVDT). The output of a LVDT is obtained from the differential voltage of the 2nd transformers. As a sensor core is attached at the motion body, the output is directly proportional to the core motion. Displacement, velocity and acceleration are measure from the core length. With a comparison between the measurement result and the known value which is obtained by the precision steel tape, the accuracy and the usefulness of the proposed scheme is validated.

• 제어로봇시스템학회논문지
• /
• 제3권5호
• /
• pp.455-460
• /
• 1997

This paper presents a recoil and counter recoil motion measurement method using linear variable differential transformers(LVDT). The output of a LVDT is obtained from the differential voltage of the 2nd transformers. As the sensor core is attached to the motion body, the output is directly proportional to the core motion. Displacement, velocity and acceleration are measured from the core length. A comparison between the measurement result and the known value, which is obtained by the precision steel tape, shows that the accuracy and the usefulness of the proposed scheme is validated.

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2007년도 The 1st International Symposium on Advanced Magnetic Materials
• /
• pp.13.1-13.1
• /
• 2007

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 추계학술대회 논문집
• /
• pp.91-91
• /
• 2009

Piezoelectric micro-pump should contain the physical running parts like check valves for acquiring the unilateral motion of fluid from the alternating motion of actuators. But the check valves raise many problems such as abrasion or exhaustive destruction by the recursive mechanical displacement To solve these problems, we propose a novle type piezoelectric valveless micro-pump using peristaltic motion due to the traveling wave excitation. Proposed pump model is consisted of two piezoelectric ceramic plates, elastic metal body, caps for covering flow path, rubber rings for sealing tightly and disk springs for the pressurization of pump body.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
• /
• pp.898-900
• /
• 1998

This paper describes the motion characteristics and micro-discharge of the free conducting particles between plain electrodes under alternating voltage. The particles move between both electrodes due to electrostatic force by applied AC voltage. Various types and sizes of free conducting particles were used to study the motion and micro-discharge characteristics. The micro-discharge and breakdown were observed during the particle motion.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2003년도 추계학술대회
• /
• pp.1051-1055
• /
• 2003

Aluminum carbody for rolling stocks is light and perfectly recycled, but includes severe defects which are very dangerous to fatigue strength. Structural integrity assessment for the carbody by static load test has been performed up to date. In this study, to evaluate fatigue strength of the aluminum carbody of urban transit unit. a testing method to simulate dynamic loading condition was proposed and the fatigue strength of the carbody was evaluated. The dynamic load test results showed that the alternating stress ranges were different from the estimated ranges based on the static test results. Excessive stress ranges at the center are thought to come from the flexible motion of the carbody. published fatigue test data for aluminum components, but variation of alternating acceleration along the length due to flexibility of carbody yielded unexpected results. Because fatigue strength based on the static test results may be overestimated at the center, modification of testing method is necessary.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 하계학술대회 논문집 A
• /
• pp.130-132
• /
• 1997

In this paper, we propose a new type of tubular linear induction motor(TLIM) with two-dimensional motion. The proposed motor consists of four short primary LIMs arranged on a same circumference and a common secondary. By adopting independently energized ring-windings to the primary, we can expect the reduction of coil-end region and the freedom of alternating current supply. The secondary conductor is capable of producing anyone of rotary, linear, and helical motions by controlling the phase of supply currents in each primary winding. From the 3-D finite element analysis and the experiment, we derive the feeding conditions to increase the subsidiary rotary-force and an optimal arrangement of primary currents to reduce the number of slot.

• International Journal of Fluid Machinery and Systems
• /
• 제9권3호
• /
• pp.245-255
• /
• 2016

The alternating flow hydraulics (AFH) had demonstrated the unique features in the past. One of the most well-known inventions was the hydraulic machine-gun synchronizer, which had become the standard equipment of airplane during World War I. The studies on the AFH between 1960 and 1980 had trigged many researchers' interests and reached the summit. The disadvantages of the AFH like low efficiency and cooling difficulty had prevented the further development. Few people are engaged in studying the AFH at present. However, the unique characteristics of the AFH inspire the researchers to continuously explore the new special suitable applications. The overviews of the AFH and the new potential application in the geotechnical testing field have been discussed in this paper. First, the research results of the AFH in the past have been summarized. Then, the classifications of the AFH have been introduced in detail according to the working principle, the number of hydraulic transmission pipelines and the mode of input energy. The advantages and the disadvantages of the AFH have been discussed. A novel potential suitable application in the soil test field has been presented at last. The detailed designing ideas of a new dynamic trixial instrument have been given, which will be a more innovational and energy-saving plan according to the current studies. A series of simulation experiments have been done. The simulation results show that the proposed scheme for the new dynamic trixial instrument is feasible. The paper work will also give some inspirations in the reciprocating motion control system.