목재와 목질판상의 Dowel-Joint 판강접합 특성에 관한 비교분석

박희준,이필우(Hee Jun Park),Phil Woo Lee 한국가구학회 1990 한국가구학회지 Vol.1 No.1

The dewel joint is one of the most widely used joint types in modern woodworking, especially in wooden furniture manufacturing.<br/> L-type specimens of two solid woods(Antiaris, Sepetir) and three wood based materials (Plywood, Particleboard, and Medium Density Fiberboard), 15mm thick, 100mm wide, and 150mm long in size, were constructed with 1, 2, 3 and 4 dowels of 6, 8, and 10mm diameter by polyvinyl acetate resin adhesive in this study. Stiffness coefficient and strength of the L-type specimens were determined by the aid of universal testing machine.<br/> The stiffness coefficients of the specimens constructed with one dowel was in the 10^-3 level, indicative of flexible joints but those with 2, 3, 4 dowels were in the 10^-4 level, indicative of relatively stable joint. The 8mm dowel was superior to 6 and 10mm dowels in bending strength, and the bending strength increased with the increase of dowel number from 1 to 4, however, the increasing rate of bending strength from 1 to 2 dowels was higher than from 3 to 4 dowels.<br/> The most superior joints strength was obtained in constructions with 4 dowels of 8mm diameter for wood based materials (Plywood, particleboard and Medium Density Fiberboard) and with 4 dowels of 10mm diameter for solid wood(Antiaris and Sepetir), respectively.

송신 MIMO-OFDM 시스템의 V-BLAST 선행처리 기법

박희준(Hee-Jun Park),안진영(Jin-Young An),김상준(Sangchoon Kim) 한국정보기술학회 2010 한국정보기술학회논문지 Vol.8 No.3

In this paper, we consider a precoding scheme that reduces the receiver’s complexity in MIMO-OFDM(Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing) systems. It adopts V-BLAST(Vertical-Bell Laboratories Layered Space-Time) technique to transmit the signals and employs ZF(Zero-Forcing), ZF-QRD(QR Decomposition), MMSE(Minimum Mean Squared Error) for V-BLAST receiver. There are two ways for precoding the V-BLAST receiver in the transmit MIMO-OFDM system. An AT(Antenna Transmit) scheme organizes the V-BLAST precoder just before transmit antennas. A MT(MIMO encoder Transmit) scheme consists of the V-BLAST precoder right after MIMO encoder. We compare the BER performance between the precoding V-BLAST system and the postcoding V-BLAST system in MIMO-OFDM. The results show that the transmit MIMO-OFDM system can simplify the receiver structure without the degradation of the BER performance compared to the receive MIMO-OFDM system.

A Numerical Study on Strut-Placed Supersonic Flow in Annulus Flowfield

박희준(Hee Jun Park),주원구(Won Goo Joo) 한국전산유체공학회 2002 한국전산유체공학회 학술대회논문집 Vol.2002 No.-

In this numerical approach, strut~placed supersonic annular flow is examined. The geometrical variations of strut cause strong influence on flowfield structures. The geometrical variations are as follows ; swept effect, attack angle effect, variation of leading edge shape. These changed features such as velocity structure, pressure structure, shock-boundary layer interaction are compared and analyzed according to each geometrical configuration.

전동차의 실내소음저감 설계 우선 순위 분석

박희준(Park Hee Jun),손병구(Son Byoung Gu),김근필(Kim Geun Pil) 한국소음진동공학회 2020 한국소음진동공학회 학술대회논문집 Vol.2020 No.11

MIMO-OFDM 시스템에서 V-BLAST 수신기의 성능

박희준(Hee-jun Park),안진영(Jin-young An),김상준(Sang-choon Kim) 대한전기학회 2008 대한전기학회 학술대회 논문집 Vol.2008 No.10

본 논문은 MIMO(Multiple Input Multiple Output) OFDM(Orthogonal Frequency Division Multiplexing)시스템에서 V-BLAST(Vertical-Bell Laboratories Layered Space Time) 수신기에 대하여 성능을 비교하고 평가한다. 신호는 각각의 송신 안테나에서 독립적으로 전송되며 QPSK(Quadrature Phase Shift Keying) 방식을 이용하여 변조 되고, 송 · 수신단에 각각 2개의 안테나와 각각 4개의 안테나를 사용한다. V-BLAST 수신기로 ZF(zero-Forcing), MMSE(Minimum Mean Squared Error), ZF-OSIC(Zero Forcing - Ordered Successive Interference Cancellation), MMSE-OSIC(Minimum Mean Squared Error - Ordered Successive Interference Cancellation)를 사용한다. 모의실험 결과에서 MMSE 방식이 ZF 방식 보다 좋은 BER(Bit Error Rate)을 보이고, ZF-OSIC 방식은 ZF 방식과 MMSE 방식 보다 더 좋은 BER을 가지는 것을 확인 할 수 있으며, MMSE-OSIC 방식은 사용된 방식 중 가장 좋은 성능을 보인다.

V-BLAST 수신기를 이용한 MIMO-OFDM 시스템의 성능

박희준(Hee-Jun Park),강윤정(Yun-Jeong Kang),김상준(Sang-Choon Kim) 한국정보기술학회 2009 Proceedings of KIIT Conference Vol.2009 No.-

본 논문에서는 송신안테나와 수신안테나를 각각 4개씩 사용하는 MIMO(Multiple Input Multiple Output) - OFDM(Orthogonal Frequency Division Multiplexing) 시스템에 대하여 V-BLAST(Vertical Bell Labs Layered Space-Time) 수신기의 성능을 비교한다. 사용되는 변조 방식은 QPSK 이며, 모의실험에서 ZF(Zero-Forcing), MMSE(Minimum Mean Square Error) 각각에 QRD 방식과 SQRD 방식을 사용한 수신 방식과 SD(Sphere Decoding) 의 수신 방식을 사용한다. 모의실험 결과에서 QRD와 SQRD를 사용하면 성능이 향상 되면서도 연산량이 줄어드는 것을 보이고, SD는 가장 좋은 성능을 보이며 이는 수신기 중 가장 성능이 좋다고 알려진 ML 방식과 같은 성능을 내면서도 연산량이 줄어듦을 보인다. In this paper, we compare V-BLAST(Vertical Bell Labs Layered Space-Time) receiver using 4 transmit antenna and 4 receive antenna in MIMO-OFDM(Multiple Input Multiple Output - Orthogonal Frequency Division Multiplexing) system. It modulate signal to QPSK. In simulation, we use technique of ZF-QRD, ZF-SQRD, MMSE-QRD, MMSE-SQRD, SD. Technique of QRD and SQRD can improve BER performance and reduce computational effort. SD has best BER performance. This is similar in ML receiver which is known for best BER performance. And SD can reduce computational efforts.

다중경로 채널에서 MIMO-OFDM 수신기 성능 비교

박희준(Hee-Jun Park),안진영(Jin-young An),김상준(Sang-Choon Kim) 한국통신학회 2009 한국통신학회 학술대회논문집 Vol.2009 No.6

國産 파티클보드와 導入 美松 및 라왕材로 製作한 移動式 선반의 Creep 擧動

박희준(Hee Jun Park),이필우(Phil Woo Lee) 한국가구학회 1993 한국가구학회지 Vol.4 No.1

This study was carried out to investigate the creep behavior of domestic particleboard and imported Douglas-fir and lauan solid boards to evaluate the suitability of domestic particleboard as shelves for furni ture<br/> All shelves were cut into 20.0 by 94.0 em size and were subjected to a creep test under a uniformly distributed load of 0.022 kgf/cm2 for 96 hours.<br/> Total deflections of 15mm and 18mm thickness particleboard were very higher than those of Douglas-fir and White lauan solid during the testing periods.<br/> For all shelves, the values of relative creep increased linearly with time but creep modulus decreased during 96 hours.<br/> The predicted length over deflection ratios were 26.55 and 46.73 for 15mm and 18mm thickness particleboard. respectively, But the values for Douglas-fir and white lauan were 164.84 and 103.09, respectively. which were very higher than those of

금융소득 종합과세에 관한 연구 -기준금액 인하의 영향을 중심으로-

박희준 ( Hee Jun Park ),정래용 ( Rae Yong Jung ) 홍익대학교 법학연구소 2014 홍익법학 Vol.15 No.3

In this study, there is an examination on market situations and problems in accordancewith the changes of standard amount of general taxation and discussion about itsimprovement plan. First, when standard amount of general taxation is lowered from 40 million to 20million won, the fund might be concealed abroad due to an evasion of general taxation. Thus, with reference to global situation, standard amount is reduced gradually and it isabolished. At last, it is able to raise the transparency of financial market. Second, as for saving insurance, It is excessively large amount in non-taxableconditions so that the conditions for limitation and term tighten up. And during theinsurance payment term, reporting system about the assessable payment or the conditionfor insurance payment is made every year. then the insurance also is in the samecategory as other financial items and manages tax resources. Third, With the reinforcement on penal provision of borrowed account possession, itimposes on the minimum of penalty in case of voluntary report within certain periodof time. Therefore, an incorporation of fund concealing is led into the financial market system in this country. Fourth, as a judgment on income in health insurance fee system is based on generalincome tax which is taken over from National Tax Administration, Therefore classifiedtaxation income such as a transfer income and a retirement income etc., non-taxableincome, and taxation income should be included in standard of assessment of healthinsurance fee.Then, it will provide the fair equal split of insurance on classification of income.

이태리 포플라와 낙엽송 세이빙으로 제조한 보드의 휨강도와 박리강도

박희준(Hee Jun Park),윤형운(Hyoung Un Yoon),이필우(Phil Woo Lee) 한국가구학회 1996 한국가구학회지 Vol.7 No.1

Non-oriented shaving boards were made with Italian popular(Populus canadensis Moench), Japanese larch(Larix letolepis Gorden) planer shavings and commercal coarse chips and UF resin, PF resin and MDI adhesives.<br/> Physical properties and manufacturing cost were ε valuated. Physical properties evaluated were static bending and internal bond strength.<br/> Boards made of lower density species were superior static bending properties to particleboard made of coarse chips and commercial particleboard. Especially, boards of shavings from low density species shower superior mechanical properties according to increasing the compression ratio.<br/> As a result, the shaving board, though its specific gravity is lowered by 0.05 to 0.1, is expected<br/> not to be less than commercial particleboard in physical properties.<br/>