플랜지가 있는 제품에서 부분패드의 영향에 관한 연구

고관영,허주환,문정효,장재석,김동윤,정민섭,김주찬,박기용,이강연,조명우,이권진,조영호,이효걸,김주호,이경희 울산과학대학 2000 연구논문집 Vol.27 No.1

본 논문에서는 기존의 Motion-JPEG 기반 감시시스템에서 낮은 동영상 압축성능 문제를 해결하기 위한 새로운 동영상 압축기법을 제안하였다. 제안된 방법에서는 현재 프레임의 JPEG 데이터 중 변화된 압축 데이터만이 실시간으로 추출하고 저장된다. 제안된 방법에 의해 저장된 데이터는 기존의 JPEG과는 다른 고유의 포맷을 가지기 때문에, 동영상 데이터는 더욱 안전하게 유지될 수 있다. 실험을 통해, 제안된 동영상 압축기법의 압축률이 기존의 Motion-JPEG 기반 감시시스템에 비해 3배정도 높다는 것을 확인할 수 있었다.

Overview of KSTAR research progress and future plans toward ITER and K-DEMO

Park, H.K.,Choi, M.J.,Hong, S.H.,In, Y.,Jeon, Y.M.,Ko, J.S.,Ko, W.H.,Kwak, J.G.,Kwon, J.M.,Lee, J.,Lee, J.H.,Lee, W.,Nam, Y.B.,Oh, Y.K.,Park, B.H.,Park, J.K.,Park, Y.S.,Wang, S.J.,Yoo, M.,Yoon, S.W.,B IOP 2019 Nuclear fusion Vol.59 No.11

<P>A decade-long operation of the Korean Superconducting Tokamak Advanced Research (KSTAR) has contributed significantly to the operation of superconducting tokamak devices and the advancement of tokamak physics which will be beneficial for the ITER and K-DEMO programs. Even with limited heating capability, various conventional as well as new operating regimes have been explored and have achieved improved performance. As examples, a long pulse high-confinement mode operation with and without an edge-localized mode (ELM) crash was well over 70 and 30 s, respectively. The unique capabilities of KSTAR allowed it to improve the capability of controlling harmful instabilities, and they have been instrumental in uncovering much new physics. The highlights are that the L/H transition threshold power is sensitive to the resonant magnetic perturbation (RMP) and insensitive to non-resonant magnetic perturbation. Co-<I>I</I> <SUB>p</SUB> offset rotation dominated by an electron channel predicted by general neoclassical toroidal viscosity theory was confirmed. Improved heat dispersal in a divertor system using three rows of rotating RMP was demonstrated and predictive control of the ELM-crash with <I>a priori</I> modeling was successfully tested. In magnetohydrodynamic physics, validation of the full reconnection model (i.e. <I>q</I> <SUB>0</SUB>  >  1 right after the sawtooth crash) and self-consistent validation of the anisotropic distribution of turbulence amplitude and flow in the presence of the 2/1 island with theoretical models were achieved. The turbulence amplitude induced by RMP was linearly increased with the slow RMP coil current ramp-up time (i.e. the magnetic diffusion time scale). The <I>D</I> <SUB> <I>α</I> </SUB> spikes (i.e. ELM-crash amplitude) was linearly decreased with the turbulence amplitude and not correlated with the perpendicular electron flow. In the turbulence area, a non-diffusive ‘avalanche’ transport event and the role of a quiescent coherent mode in confinement were studied. To accommodate the anticipation of a higher performance of the KSTAR plasmas with the increased heating powers, a new divertor/internal interface with a full active cooling system will be implemented after a full test of the new heating (neutral beam injection II and electron cyclotron heating) and current drive (CD) (Helicon and lower hybrid CD) systems. An upgrade plan for the internal hardware, heating systems and efficient CD system may allow for a long pulse operation of higher performance plasmas at <I>β</I> <SUB>N</SUB>  >  3.0 with <I>f</I> <SUB>bs</SUB> ~ 0.5 and <I>T</I> <SUB>i</SUB>  >  10 keV.</P>

Features and Properties of $YBa_2$$Cu_3$$O_{7-x}$ Films Grown on SrTi$O_3$ by High Frequency PLD

Shi, D.Q.,Ko, R.K.,Song, K.J.,Chung, J.K.,Choi, S.J.,Park, Y.M.,Shin, K.C.,Yoo, S.I.,Park, C. The Korean Superconductivity Society 2003 Progress in superconductivity Vol.5 No.1

YBCO films were deposited with various thicknesses from 100nm to 1.6$\mu\textrm{m}$ on single crystal $SrTiO_3$ substrates by pulsed laser deposition (PLD). The effects of different deposition conditions, especially different deposition rates by means of changing the pulsed laser frequency up to 200Hz, on the J$_{c}$ value were studied. For YBCO film with the thickness of 200nm, the $J_{c}$ value of $2.1MA/\textrm{cm}^2$ has been achieved under the high deposition rate of 3.2nm/s (190nm/min). The $J_{c}$ can be maintained greater than $1M/\textrm{cm}^2$ with the thickness less than 1$\mu\textrm{m}$. The X-ray analysis was used to examine the texture, crystallization and surface quality. The SEM was employed to analyze the surface of YBCO, and it was shown the surface of YBCO film became rougher with increasing the thickness. There were many large singular outgrowths and networks of outgrowths on the surface of YBCO films which lowered the density of thick YBCO film. The outgrowth network was probably the a-axis YBCO corresponding to XRD $\theta$-2$\theta$scan and $\chi$-scan which were used to characterize a-axis orientation of YBCO film. The reason for J$_{c}$ declining with increasing the thickness was studied and discussed.sed.

Current Status of the KSTAR TF Superconducting Magnet Development

ByoungSu Lim,C. S. Kim,D. J. Kim,D. K. Lee,G. S. Lee,H. K. Park,I. S. Woo,J. S. Bak,J. Y. Choi,J.J. Joo,K. Pak,K. Kim,K. P. Kim,M. S. Ko,N. H. Song,S. Lee,S. J. An,W. Chung,W. W. Park,Y. J. Song 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.III

The KSTAR (Korea Superconducting Tokamak Advanced Research) TF magnet system is a fully superconducting magnet system which consists of 16 TF coils. The TF coil system provides a field of 3.5 T at a plasma center, with a peak flux density at the TF coils of 7.5 T. The stored energy is 470 MJ. TF coils use a Nb3Sn superconducting strand with Incoloy alloy 908 (afterward, Incoloy 908) conduit. The Nb3Sn strand has KSTAR HP-III specifications in which the critical current density is greater than 750 A/mm2 at 12 T, 4.2 K. The nominal current of the TF coils is 35.2 kA with all coils in series. For the fabrication of CICC (Cable-In-Conduit Conductor), a continuous CICC jacketing system is developed, and the procedures of coil fabrication are established to develop the TF coil. The prototype TF coil and the TF 01 16 coils are fabricated for the KSTAR superconducting magnet system. The TF17 coil which will be used as a back up coil is under fabrication. The overall TF coil fabrication will be completed by the end of December 2005.=

자유드로잉 제품과 패드를 설치한 드로잉 제품의 특성

고관영,명노훈,하종성,이창수,최창권,최병용,허기영,김광수,김동수,장종훈,장윤철,김세환,오정민,하민정,박향자 울산과학대학 2000 연구논문집 Vol.27 No.1

본 연구는 자체 제작한 전체 패드가 부착된 드로잉 금형을 이용하여 SUS, 연강, AI, 6:4황동 판재를 드로잉 가공하여 생산된 제품의 특성을 자유드로잉 하여 얻은 제품의 특성과 비교 분석하였다. SUS 판재의 경우 제품에 발생하는 현상은 벽 주름, 구변주름, 수직 파단, 드로잉상처, 이어링이 발생하였으며 길이변화는 펀치어깨부분에서 가장 많이 늘어남을 볼 수 있었고 벽 주름 부분에 있어서 접혀진 부분은 상대적으로 적게 늘어남을 볼 수 있었다. 연강 판재는 SUS 판재에서 보여준 현상을 나타내었으나 SUS 판재에 비해 수직 파단은 적게 일어난 반면 이어링이 더 크게 일어났다. AI 판재의 경우 수직 파단은 일어나지 않았으나 플랜지 주름과 밑면터짐이 발생하였다. 6:4황동의 경우는 전체패드의 AI 판재 드로잉에서와 같이 밑면터짐과 플랜지 주름의 발생이 일어났다.

High pyroelectric power generation of 0.7Pb(Mg_1/3Nb_2/3)O₃-0.3PbTiO₃ single crystal

Ko, Y.J.,Park, Y.K.,Yun, B.K.,Lee, M.,Jung, J.H. Elsevier 2014 Current Applied Physics Vol.14 No.11

<P>We report the pyroelectric power generation of a relaxor ferroelectric 0.7Pb(Mg1/3Nb2/3)O-3-0.3PbTiO(3) (PMN-PT) single crystal. For a temperature variation rate of 0.5 K/s, the PMN-PT generated a closed-circuit current of 10 nA and an open-circuit voltage of 1.1 V at room temperature. The pyroelectric current and voltage of the PMN-PT single crystal were proportional to the temperature variation rate and were sharply enhanced near the structural phase-transition temperature. Additionally, the PMN-PT pyroelectric generator produced stable power for excessive thermal cycling and was highly sensitive to random thermal fluctuations. Our results indicate the potential importance of PMN-PT for high-power pyroelectric generator applications. (C) 2014 Elsevier B.V. All rights reserved.</P>

아미노산 첨가수준에 따른 산란계용 사료의 단백질절약 효과

고영두,하정기,곽종형,강대진,송우준,한인규 경상대학교 축산진흥연구소 1981 畜産振興硏究所報 Vol.8 No.1

드로잉 금형에 있어서 비드의 영향

고관영,최원정,조재희,명노훈,이창수,최병용,허주환,최창권,장종훈,장윤철,박기용 울산과학대학 2001 연구논문집 Vol.28 No.1

본 연구는 자체 제작한 다이 측 비드가 설치 된 드로잉 금형을 이용하여 SUS 304, 6:4 황동 판재를 드로잉 가공하여 생산된 제품의 치수변형 특성을, 비드를 설치하지 않은 자유 드로잉 하여 얻은 제품과 비교하였다. SUS 304 판재의 경우, 비드를 설치하여 드로잉 한 경우는 늘어난 길이의 변화가 연속적으로 증가하고 있고, 비드를 설치하지 않은 경우는 마지막 부분에서 다시 회복상태를 보였다. 그 원인은 드로잉 비드로 인하여 적정량의 유입으로 일정 비율로 늘어난 것이라고 볼 수 있다. 6:4 황동 판재의 경우는 비드를 설치한 경우의 치수 변형값이 비드를 설치하지 않은 경우보다 안정함을 보여주었다. In this research, properties of SUS 304 and 6:4 brass products produced by die bead-drawing mold were compared with those of products drawed without bead. In the case of bead-SUS-plate, variation of incremental length progressively increases, while, in the case of no bead-SUS-plate, recovery appeared at the final-part. The reason of this difference is considered as proper insert of metal-plate on the basis of bead. Bead-6:4 brass-plate showed more stable data than no-bead die case although it did not show recovery in final-part.

미생물 발효제 처리 돈분액비 시용이 사료작물생산성 및 토양의 이화학적 성상에 미치는 영향

황경준(K. J. Hwang),박형수(H. S. Park),박남건(N. G. Park),고문석(M. S. Ko),김문철(M. C. Kim),송상택(S. T. Song) 한국초지조사료학회 2006 한국초지조사료학회지 Vol.26 No.4

본 시험은 제주도내 발생하는 돈분액비의 활용도를 높이고 화학비료 사용 절감 및 대처하는 목적으로 수행되어졌다. 품종 간의 건물수량은 수수×수단그라스가 1,480.4 ㎏/10a 로 가장 높았으며, 수수×수수교잡종이 1,444.9.5 ㎏/10a, 옥수수 1,054.6 ㎏/10a로 나타났다(p<0.01). 처리별 건물수량은 미생물제제를 처리한 돈분액비가 1,562 ㎏/10a로 높게 나타났으며, 돈분액비 시용구는 1,410 ㎏/10a, 화학비료구 1,008 ㎏/10a로 나타났다(p<0.01). 토양성분은 시험 전 1.32 ppm이었던 Zn 함량이 시험 후 화학비료구, 돈분액비구, 미생물제제를 처리한 돈 분액비구에서는 4.23, 4.12, 4.00 ppm으로 나타났으며, Cu 함량은 시험 전 0.59 ppm, 시험 후에 토양에서는 화학비료구, 돈분액비구, 미생물 제제를 처리한 돈분액비구에서는 각각 0.821, 0.854, 1.027 ppm으로 높아졌다. 이 시험의 결과로 미생물제제를 처리한 돈분액비가 화학비료구나 일반돈분액비에 비해 비료성분이 떨어지지 않으며 관수효과까지 있어 사료작물에 적합한 비료자원이라 할 수 있겠다. This study was carried out to determine the effect of chemical fertilizer and two fermented types of pig slurry on the dry matter(DM) yield of three crops and chemical properties. The experiment design was a slit plot with three replications. Main plots consist of three crops : sorghum×sudangrass hybrid(‘SS405’), sudangrass(‘Jumbo’), corn(‘DK501’). Sub plots consist of three treatments : chemical fertilizer (CF N-200, P-150, K-150 ㎏/ha), aerobic fermented pig slurry (APS 200 ㎏ N/ha), and aerobic fermented pig slurry treated with probiotics (APS+P 200 ㎏ N/ha). Plant heights with three crops per sudangrass (380.3㎝) was the longest (p<0.01). Dry matter yield of aerobic fermented pig slurry treated with probiotics was the highest the other treatments (p<0.01). Crude protein (CP) content were highest in sorghum×sudangrass hybrid than in the other crops. Cupper content(%) were highest in aerobic fermented pig slurry treated with probiotics than in the other treatments.

Thermal and Electrical Stabilities of Solid Nitrogen (SN2) Cooled YBCO Coated Conductors for HTS Magnet Applications

Song, J B,Kim, K J,Kim, K L,Lee, J H,Kim, H M,Lee, G H,Chang, H M,Park, D K,Ko, T K,Lee, H G IEEE 2010 IEEE transactions on applied superconductivity Vol.20 No.3

<P>Recently, a cooling system using a solid cryogen such as solid nitrogen (SN2), was introduced for high temperature superconducting (HTS) magnet applications. In order to apply the SN2 cooling system successfully to HTS applications, it is essential to obtain sufficient data regarding the characteristics of the SN2-cooled YBCO-coated conductor (CC), including the thermal and electrical properties. Therefore, this study examined the effect of SN2 on the thermal/electrical stability of YBCO CC tape. The SN2 was produced by conduction cooling using a GM-cryocooler and cooled to 58 K. The voltages and temperatures of the YBCO CC tapes were measured while applying an over-current. The results showed that the thermal and electrical stability of the YBCO CC tape were improved considerably in the SN2 cooling system compared to that in the conduction cooling system.</P>