A Novel Analysis of <tex> ${L}_{\text{gd}}$</tex> Dependent-1/ <tex> ${f}$</tex> Noise in In_0.08Al_0.92N/GaN

Seo, Jae Hwa,Yoon, Young Jun,Son, Dong-Hyeok,Kim, Jeong-Gil,Lee, Jong-Ho,Lee, Jung-Hee,Im, Ki-Sik,Kang, In Man IEEE 2018 IEEE electron device letters Vol.39 No.10

<P>In<SUB>0.08</SUB>Al<SUB>0.92</SUB>N/GaN fin-type high-electron mobility transistors (fin-HEMTs) with different gate-to-drain lengths ( <TEX>${L} _{\text {gd}}$</TEX>) are fabricated and characterized by dc and low-frequency noise (LFN) measurements. The fabricated device with the largest <TEX>${L} _{\text {gd}}$</TEX> exhibits the degradation of the maximum drain current and transconductance with a positive shift of the threshold voltage. LFN measurements of the In<SUB>0.08</SUB>Al<SUB>0.92</SUB>N/GaN fin-HEMTs reveal clear 1/ <TEX>${f}$</TEX> behavior of the noise spectra, and the minimum value is observed in the device at <TEX>${L} _{\text {gd}} = {20}\,\,\mu \text{m}$</TEX>. The devices with smaller <TEX>${L} _{\text {gd}}$</TEX> follow a carrier number fluctuation noise model owing to electron trapping/detrapping into the In<SUB>0.08</SUB>Al<SUB>0.92</SUB>N barrier layer from the 2-D electron gas (2DEG) channel. In contrast, the device with the largest <TEX>${L} _{\text {gd}}$</TEX> shows correlated mobility fluctuations due to the large 2DEG mobility fluctuations in the large access area.</P>

블록 정렬과 선두이동법을 이용한 VF산술부호에 의한 데이터 압축

李振鎬,南寅佶 慶一大學校 1997 論文集 Vol.14 No.2

In this paper, we present the loseless data compression using block-sorting, move to front(MTF) and arithmetic code based on run-length model. First, the substrings which is parsed into length N are shifted one by one symbol, Second the cyclic shifted rows are sorted substring. As the sequences by MTF tend to have a long consecutive symbol, the coding based on run-length model is efficient to compress the transformed sequence. Then the preprocessed sequence is coded using VF(variable to fixed) arithmetic code which can be limited the error propagation in one block. The key point is how to split the fixed length codeword in proportion to symbol probabilities in VF arithmetic code. We develop the new VF arithmetic coding that split completely the codeword set for arbitrary source alphabet. In addition to, an extended representation of symbol probability is designed by using recursive Gray conversion. The performance of proposed method is compared with other well-known source coding methods with respect to entropy and compression ratio.

영구자석 동기발전기의 정주파수 정전압 출력에 관한 연구

우정인,조용길,황정원,송호신 동아대학교 공과대학 부설 한국자원개발연구소 1994 硏究報告 Vol.18 No.2

The permanent magnet machines have the advantages of high efficiency and power density, features very improtant for air-borne applications with their requiement of no external dc supply for rotor excitation, in addition, a very lower synchronous reactance thus making it a stiff source of power with a higher steady state and more transient capability than ist counterpart, the wound rotor type. In this paper, The permanent magnet synchronous machine is taken as a power source in the variable speed constant frequency power conversion scheme with converter-inverter system. All digital routines are excuted in the sampling time of 100 micro second by a DSP Board (TMS320c25) with A/D converters, which is detect the load current, capacitor current and DC link voltage at a sudden load change and to compute the predicted current. In one sampling interval, two optimal space voltage vectors as well as tow zero voltage vectors are employed so that the capacitor current may follow the reference. As a result, sinusoidal output constant voltage is obtained while swiching frequency is constant, and experimental results are presented, which shows the effectiveness of the proposed control method.

Mechanotransduction of human pluripotent stem cells cultivated on tunable cell-derived extracellular matrix

Kim, In Gul,Gil, Chang-Hyun,Seo, Joseph,Park, Soon-Jung,Subbiah, Ramesh,Jung, Taek-Hee,Kim, Jong Soo,Jeong, Young-Hoon,Chung, Hyung-Min,Lee, Jong Ho,Lee, Man Ryul,Moon, Sung-Hwan,Park, Kwideok Elsevier 2018 Biomaterials Vol.150 No.-

<P><B>Abstract</B></P> <P>Cell-derived matrices (CDM) are becoming an attractive alternative to conventional biological scaffolding platforms due to its unique ability to closely recapitulate a native extracellular matrix (ECM) de novo. Although cell-substrate interactions are recognized to be principal in regulating stem cell behavior, very few studies have documented the acclimation of human pluripotent stem cells (hPSCs) on pristine and altered cell-derived matrices. Here, we investigate crosslink-induced mechanotransduction of hPSCs cultivated on decellularized fibroblast-derived matrices (FDM) to explore cell adhesion, growth, migration, and pluripotency in various biological landscapes. The results showed either substrate-mediated induction or inhibition of the Epithelial-Mesenchymal-Transition (EMT) program, strongly suggesting that FDM stiffness can be a dominant factor in mediating hPSC plasticity. We further propose an optimal FDM substratum intended for long-term hPSC cultivation in a feeder-free niche-like microenvironment. This study carries significant implications for hPSC cultivation and encourages more in-depth studies towards the fundamentals of hPSC-CDM interactions.</P>

Streptomyces thermocyaneoviolaceus의 Xylanase 생산조건 및 Xylooligo당의 생산

주길재,박희동,최준호,이인구,이오석,권달호 慶北大學校農業科學技術硏究所 1998 慶北大農學誌 Vol.16 No.-

농산폐자원으로부터 기능성물질인 xylooligo당을 생산하기 위해서 내열성 균주인 S.thermocyaneoviolaceus가 생산하는 xylanase의 생산최적조건을 검토한 결과 0.8% 밀기울, 0.06% yeast extract, 0.06% bactopeptone, 0.05% MgSO₄·7H₂O, 0.005% FeSO₄·7H₂O, 0.05% KH₂PO₄및 0.2% K₂HPO₄를 함유한 배지(pH7.0)에서 50℃, 24시간 배양시 최고효소활성(2.47 unit/ml)의 배양상징액을 얻을 수 있었다. 효소의 최적반응조건은 pH5.5, 65℃였다. 또한 pH안정성을 조사한 결과 pH4.5∼9.5사이에서 4℃에서 12시간후에도 80% 이상의 효소활성을 유지하였고, 열 안정성은 60℃에서 1시간 처리후 94%이상의 효소활성을 유지하는 내열성이 있는 효소였다. 생산된 xylanase birchwood xylan 반응생성물을 TLC 및 HPLC로 확인해 본 결과, pH가 낮을수록(pH 5.0∼6.0) xylobiose와 xylotriose및 소량의 xylose의 양이 증가하였고, pH가 높을수록 (pH8.0∼9.0) X₄이상의 각종 xylooligo당의 양이 상대적으로 증가하였다. 또한 24 시간후에는 xylan의 상대량이 25% 이하로 감소하면서 주분해산물로 xylobiose가 생산되었으며 xylotriose와 xylose 및 X₄이상의 각종 xylooligo당이 생산되었다. A thermotolerant bacterium, Streptomyces thermocyaneoviolaceus which produced xylan-degrading enzymes, utilized excellently xylan of wheat bran by producing the enzymes in comparison with that of birchwood or oat spelts. Optimal enzyme production was achieved in WB medium containing 0.8% wheat bran, 0.06% yeast extract, 0.06% bactopeptone, 0.05% MgSO₄·7H₂O, 0.05% FeSO₄·7H₂O, 0.05% KH₂PO₄ and, 0.2% K₂HPO₄(pH 7.0) at 50℃ for 24 hrs. The optimal pH and temperature for the hydrolysis of xylan were pH 5.5 and 65℃, respectively. The enzyme activity was retained more than 80% at the range from pH 4.5 to pH 9.5 at 4℃ for 12 hrs and 94% on the heat-treatment at 65℃ for 1 hr. Xylobiose, xylotriose, xylose, and other xylooligosaccharides were produced as end products from hydrolysis of birchwood xylan by the xylanase of S. thermocyaneoviolceus.

GO에 의해 유도된 培養 脊髓感覺神經細胞 독성에 대한 鎭肝熄風湯의 방어효과

박광수,이호승,김인수,강길성,김인규,김인섭,류도곤 한국전통의학연구소 2003 한국전통의학지 Vol.13 No.1

To evaluate the effect of Jingansikpungtang water extract on cultured mouse spinal sensory neuron which was inhibited by glucose oxidase(GO)-induced cytotoxicity, NR assay and TBARS assay for lipid peroxidation were carried out after the cultured mouse spinal sensory neuron were pre-incubated with various concentrations of Jingansikpungtang water extract for 3 hours prior to exposure of GO. GO, a oxygen radical, decreased the survival rate of the cultured mouse spinal sensory neuron cells on NR assay. Jingansikpungtang water extract have efficacy of decreasing lipid peroxidation increasing by GO in cultured mouse spinal sensory neuron. From above the results, it is concluded that Jingansikpungtang has marked efficacy as a treatment for the damages caused in the GO-mediated oxidative process.

양측 하악과두 골절에 대한 관혈적 정보술후 나타난 근약화와 시력장애 : 증례보고

정기훈,신용길,김태열,신재명,윤규호,전인성 대한악안면성형재건외과학회 2000 Maxillofacial Plastic Reconstructive Surgery Vol.22 No.6

The condylar fracture show high occurrence rate in the following of symphysis and angle, because it is easy to have concentration of outer pressure due to its long and narrow anatomical shape and mouth opened state when trauma is attacked. For the clinical findings, there are trismus, opening deviation, mal-occlusion and open bite The classification of condylar fracture is varied due to the location of condylar bone fragment, fracture site. There are conservative and surgical methods for treatment modalities. Because of many advantages, conservative method is widely used it has no particular limits of treatment adjustment but the cases of absolutely surgical correction indication are easily found in clinical experience. Although many methods are suggested for treatments of condylar fracture, there are no particular surgical methods for precise reduction due to difficult accessibility in high condylar neck fracture. For precise reduction of condyle, we used Nam's method. However, in Nam's method, because condyle is fixed when once it is kept off externally reduced in avascular state, so complication such as condyle resorption is pointed out as a problem. In our clinic, we obtained some knowledge by treating a patient who had muscle weakness and vision disorder after temporary airway obstruction follownig the both condylar fracure operated using Nam's method, so here we reported the case with a study of documents.

그라인더(grinder) 사용에 의한 Hand-Arm Vibration Syndrome(HAVS)의 6예

임상혁,김록호,양길승,양정인,김상섭,전형준,박시복 大韓産業醫學會 2000 대한직업환경의학회지 Vol.12 No.3

목 적 : 수지증상이 있는 진동공구 작업자 8명에 대해 객관적이고 체계화된 진단방법을 이용하여 수지진동 증후군을 진단하고자 시행하였다. 방 법 : 과거병력, 가족력 등의 문진과 혈액 및 소변, 방사선 검사를 통해 다른 원인에 의한 레이노씨병을 배제하였고, 공구 측정 결과를 이용하여 작업과의 관련성을 보았으며, 냉수 침지검사와 근전도 검사를 통하여 수지진동 증후군을 진단하고자 하였다. 결 과 : 수지증상이 있는 진동공구 작업자 8명에 대해 과거병력, 가족력, 약물복용 및 과거 직업력 등 레이노씨병을 유발하는 요인에 대하여 조사하였고 특이점은 발견하지 못하였다. 다른 원인에 의한 레이노씨병을 배제하기 위해 혈액 및 소변, 방사선 검사를 하였고 8명 모두에서 특이 소견을 발견하지 못하였다. 위의 문진과 검사결과로 다른 원인에 의한 레이노씨병을 배제할 수 있었다. 해당사업장의 진동 공구 측정결과를 근거로 피검자의 공구가 ISO의 허용기준을 초과함을 알 수 있었다. 냉수 침지검사와 근전도 검사를 이용하여 피검자 8명중 6명이 말초 혈액순환 장해와 말초 신경염이 있는 것으로 진단되었다. 위의 내용을 근거로 6명은 진동에 의한 수지 진동 증후군으로 진단할 수 있었다. 결 론 : 수지증상이 있는 진동공구 작업자 8명에 대해 객관적이고 체계화된 진단방법을 이용하여 수지진동 증후군을 진단하였다. 해당 사업장의 진동 공구 작업자의 진동에 대한 검진이 필요할 것으로 생각된다. Objectives : To confirm the HAVS In workers exposed to hand-arm vibration with using the objective diagnostic methods. Methods : Several tests were used to help substantiate a clinical diagnosis of HAVS. Some other diseases were excluded by a medical interview, hematologic assessment, urinalysis, X-rays. The hand-arm vibration acceleration level of the grinder was evaluated for considering HAVS. Peripheral vascular changes were examined by a cold provocation test. An electromyography was implemented to ascertain the peripheral neural changes. Results : 8 workers with symptoms in hands & fingers, exposed to hand-arm vibration were examined. Some other diseases (primary Raynaud's disease, secondary Raynaud's disease in not occupational origin) were excluded by a medical interview, hematologic assessment, urinalysis, X-rays. The hand-arm vibration acceleration level of the grinder was 7.9 m/sec2. The recovery time of a skin temperature followed finger cooling was significantly prolonged in 6 workers with HAVS. The nerve conduction velocity was reduced in 6 workers with HAVS. Conclusions : So we report 6 cases of HAVS in grinding workers exposed to hand-arm vibration diagnosed objectively by an exclusion of some other disease, hand- arm vibration acceleration level, cold provocation test, electromyography.

전력수용가포털을 위한 구내 통신 및 컴퓨터 네트워크 용량 설계

홍준희(Jun-Hee Hong),최중인(Jung-In Choi),김진호(Jin-Ho Kim),김창섭(Chang-Sub Kim),손성용(Sung-Young Son),손광명(Kwang-Myung Son),장길수(Gil-Soo Jang),이재복(Jea-Bok Lee) 한국조명·전기설비학회 2007 조명·전기설비학회논문지 Vol.21 No.10

고전력수용가포털(Consumer Portal)은 소비자의 다양한 장치들과 광역 네트워크, 그리고 에너지서비스사업자 (ESP: 한전 등)의 서비스 애플리케이션 플랫폼을 연결하는 물리적 링크이자 논리적 결합으로, 전력서비스 체계에서 소비자-공급자 간 정보교환과 서비스 거래를 담당하는 양방향 통신의 핵심 인프라로서 포털이다. 전력수용가포털(Consumrr Portal)의 성공적인 설계와 개발을 위해서는 효율성, 경제성, 확장성을 고려한 네트워크 설계가 선행되저야 한다. 그러나 전력수용가 포털의 네트워크 설계에 필요한 네트워크 용량 설계 모델링에 대한 공학적 연구는 아직 부족한 실정이다. 본 논문에서는 전력수용가포털의 네트워크 설계에 필요한 네트워크 용량 설계 모델링 방법을 논하고 실제 구축중인 시스템에 적용하였다. 그 결과 기존 네트워크 설계방법의 문제점을 파악하고, 개선하여 네트워크의 최대수용 단말기의 수를 30~40배 증대시킬 수 있는 데이터 수집 알고리즘을 개발할 수 있게 되었다. Consumer Portal is defined as a combination of hardware and software that enables two-way conmunication between energy service providers(ESP, like KEPCO) and equipment within the consumer's premises. The portal provides both a physical link (between wires, radio waves, and other media) and a logical link (translating among language-like codes and etiquette-like protocols) between in-building and wide-area access networks. Thus, the consumer portal is an important, open public shared infrastructure in the future vision of energy services. In this paper, we describe a new methodology for local communication and computer network capacity design of consumer portal, and also presents capacity calculation method using a network system limitation factors. By the approach, we can check into the limitations of existing methods, and propose an improved data processing algorithm that can expand the maximum number of the networked end-use devices up to 30-40 times. For validation, we applies the proposed methode to our real system design. Our contribution will help electrical power information network design.

Enhanced activation of NAD(P)H: quinone oxidoreductase 1 attenuates spontaneous hypertension by improvement of endothelial nitric oxide synthase coupling via tumor suppressor kinase liver kinase B1/adenosine 5&vprime;-monophosphate-activated protein kina

Kim, Yong-Hoon,Hwang, Jung Hwan,Kim, Kyung-Shim,Noh, Jung-Ran,Gang, Gil-Tae,Oh, Won Keun,Jeong, Kyeong-Hoon,Kwak, Tae Hwan,Choi, Hueng-Sik,Lee, In-Kyu,Lee, Chul-Ho Wolters Kluwer Health | Lippincott Williams Wilkin 2014 Journal of Hypertension Vol.32 No.2

AIMS:: Guanosine 5&vprime;-triphosphate cyclohydrolase-1 (GTPCH-1) is a rate-limiting enzyme in de-novo synthesis of tetrahydrobiopterin (BH4), an essential cofactor for endothelial nitric oxide synthase (eNOS) coupling. Adenosine 5&vprime;-monophosphate-activated protein kinase (AMPK) is crucial for GTPCH-1 preservation, and tumor suppressor kinase liver kinase B1 (LKB1), an upstream kinase of AMPK, is activated by NAD-dependent class III histone deacetylase sirtuin 1 (SIRT1)-mediated deacetylation. &bgr;-Lapachone has been shown to increase cellular NAD/NADH ratio via NAD(P)H:quinone oxidoreductase 1 (NQO1) activation. In this study, we have evaluated whether &bgr;-lapachone-induced NQO1 activation modulates blood pressure (BP) through preservation of GTPCH-1 in a hypertensive animal model. METHODS AND RESULTS:: Spontaneously hypertensive rats (SHRs), primary aortic endothelial cells, and endothelial cell line were used to investigate the hypotensive effect of &bgr;-lapachone and its action mechanism. &bgr;-Lapachone treatment dramatically lowered BP and vascular tension in SHRs and induced eNOS activation in endothelial cells. Consistent with these effects, &bgr;-lapachone treatment also elevated levels of both aortic cGMP and plasma nitric oxide in SHRs. Meanwhile, &bgr;-lapachone-treated SHRs showed significantly increased levels of aortic NAD, LKB1 deacetylation, and AMPK Thr phosphorylation followed by increased GTPCH-1 and tetrahydrobiopterin/dihydrobiopterin ratio. In-vitro study revealed that AMPK inhibition by overexpression of dominant-negative AMPK nearly abolished GTPCH-1 protein conservation. Enhanced LKB1 deacetylation and AMPK activation were also elicited by &bgr;-lapachone in endothelial cells. However, inhibition of LKB1 deacetylation by blocking of NQO1 or SIRT1 blunted AMPK activation by &bgr;-lapachone. CONCLUSION:: This is the first study demonstrating that eNOS coupling can be regulated by NQO1 activation via LKB1/AMPK/GTPCH-1 modulation, which is possibly correlated with relieving hypertension. These findings provide strong evidence to suggest that NQO1 might be a new therapeutic target for hypertension.