• Title/Summary/Keyword: bias cut

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A Novel Bottom-Gate Poly-Si Thin Film Transistors with High ON/OFF Current Ratio (ON/OFF 전류비를 향상시킨 새로운 bottom-gate 구조의 다결정 실리콘 박막 트랜지스터)

  • Jeon, Jae-Hong;Choe, Gwon-Yeong;Park, Gi-Chan;Han, Min-Gu
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.5
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    • pp.315-318
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    • 1999
  • We have proposed and fabricated the new bottom-gated polycrystalline silicon (poly-Si) thin film transistor (TFT) with a partial amorphous-Si region by employing the selective laser annealing. The channel layer of the proposed TFTs is composed of poly-Si region in the center and a-Si region in the edge. The TEM image shows that the local a-Si region is successfully fabricated by the effective cut out of the incident laser light in the upper a-Si layer. Our experimental results show that the ON/OFF current ratio is increased significantly by more than three orders in the new poly-Si TFT compared with conventional poly-Si TFT. The leakage current is decreased significantly due to the highly resistive a-Si re TFTs while the ON-series resistance of the local a-Si is reduced significantly due to the considerable inducement of electron carriers by the positive gate bias, so that the ON-current is not decreased much.

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Magnetic Properties of Fe-6.0 wt%Si Alloy Dust Cores Prepared with Phosphate-coated Powders (인산염 피막처리 분말을 사용한 Fe-6.0 wt%Si 합금 압분자심의 자기적 특성)

  • Jang, D.H.;Noh, T.H.;Kim, K.Y.;Choi, G.B.
    • Journal of the Korean Magnetics Society
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    • v.15 no.5
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    • pp.270-275
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    • 2005
  • Dust cores (compressed powder cores) of $Fe-6.0wt\%Si$ alloy with a size of $35\~180\;{\mu}m$ in diameter have been prepared by phosphate coatings and annealings at $600\~900^{\circ}C$ for 1 h in nitrogen atmosphere. Further the magnetic and mechanical properties of the powder cores were investigated. As a general trends, the compressive strength and core loss decreased with the increase in annealing temperature. When annealed at $800^{\circ}C$, the compressive strength was 15 kgf, the permeability and quality factor were 74 and 26, respectively. Moreover the core loss at 50 kHz and 0.1 T induction was $750\;mW/cm^3$, and the percent permeability under the static field of 50 Oe was estimated to be about 78. In addition, the cut-off frequency in the cure representing the frequency dependence of effective permeability was measured to be around 200 kHz. These properties of the $Fe-6.0wt\%Si$ alloy dust cores could be considered to be due to the good insulation effect of iron-phosphate coats, the decrease in magnetocrystalline anisotropy and saturation magnetostriction and the increase in electric resistivity.

Optimum Design of Junctionless MOSFET Based on Silicon Nanowire Structure and Analysis on Basic RF Characteristics (실리콘 나노 와이어 기반의 무접합 MOSFET의 최적 설계 및 기본적인 고주파 특성 분석)

  • Cha, Seong-Jae;Kim, Kyung-Rok;Park, Byung-Gook;Rang, In-Man
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.47 no.10
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    • pp.14-22
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    • 2010
  • The source/channel/drain regions are formed by ion implantation with different dopant types of $n^+/p^{(+)}/n^+$ in the fabrication of the conventional n-type metal-oxide-semiconductor field effect transistor(NMOSFET). In implementing the ultra-small devices with channel length of sub-30 nm, in order to achieve the designed effective channel length accurately, low thermal budget should be considered in the fabrication processes for minimizing the lateral diffusion of dopants although the implanted ions should be activated as completely as possible for higher on-current level. Junctionless (JL) MOSFETs fully capable of the the conventional NMOSFET operations without p-type channel for enlarging the process margin are under researches. In this paper, the optimum design of the JL MOSFET based on silicon nanowire (SNW) structure is carried out by 3-D device simulation and the basic radio frequency (RF) characteristics such as conductance, maximum oscillation frequency($f_{max}$), current gain cut-off frequency($f_T$) for the optimized device. The channel length was 30 run and the design variables were the channel doping concentration and SNW radius. For the optimally designed JL SNW NMOSFET, $f_T$ and $f_{max}$ high as 367.5 GHz and 602.5 GHz could be obtained, respectively, at the operating bias condition $V_{GS}$ = $V_{DS}$ = 1.0 V).

Development of a Predictive Model Describing the Growth of Listeria Monocytogenes in Fresh Cut Vegetable (샐러드용 신선 채소에서의 Listerio monocytogenes 성장예측모델 개발)

  • Cho, Joon-Il;Lee, Soon-Ho;Lim, Ji-Su;Kwak, Hyo-Sun;Hwang, In-Gyun
    • Journal of Food Hygiene and Safety
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    • v.26 no.1
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    • pp.25-30
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    • 2011
  • In this study, predictive mathematical models were developed to predict the kinetics of Listeria monocytogenes growth in the mixed fresh-cut vegetables, which is the most popular ready-to-eat food in the world, as a function of temperature (4, 10, 20 and $30^{\circ}C$). At the specified storage temperatures, the primary growth curve fit well ($r^2$=0.916~0.981) with a Gompertz and Baranyi equation to determine the specific growth rate (SGR). The Polynomial model for natural logarithm transformation of the SGR as a function of temperature was obtained by nonlinear regression (Prism, version 4.0, GraphPad Software). As the storage temperature decreased from $30^{\circ}C$ to $4^{\circ}C$, the SGR decreased, respectively. Polynomial model was identified as appropriate secondary model for SGR on the basis of most statistical indices such as mean square error (MSE=0.002718 by Gompertz, 0.055186 by Baranyi), bias factor (Bf=1.050084 by Gompertz, 1.931472 by Baranyi) and accuracy factor (Af=1.160767 by Gompertz, 2.137181 by Baranyi). Results indicate L. monocytogenes growth was affected by temperature mainly, and equation was developed by Gompertz model (-0.1606+$0.0574^*Temp$+$0.0009^*Temp^*Temp$) was more effective than equation was developed by Baranyi model (0.3502-$0.0496^*Temp$+$0.0022^*Temp^*Temp$) for specific growth rate prediction of L.monocytogenes in the mixed fresh-cut vegetables.

Prognostic Value of Vascular Endothelial Growth Factor Expression in Patients with Prostate Cancer: a Systematic Review with Meta-analysis

  • Wang, Kai;Peng, Hong-Ling;Li, Long-Kun
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.11
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    • pp.5665-5669
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    • 2012
  • Background: The vascular endothelial growth factor (VEGF) mediates vasculogenesis and angiogenesis through promoting endothelial cell growth, migration and mitosis, and has involvement in cancer pathogenesis, progression and metastasis. However, the prognostic value of VEGF in patients with prostate cancer remains controversial. Objectives: The aim of our study was to evaluate the prognostic value of VEGF in prostate cancer, and summarise the results of related research on VEGF. Methods: In accordance with an established search strategy, 11 studies with 1,529 patients were included in our meta-analysis. The correlation of VEGF-expression with overall survival and progression-free survival was evaluated by hazard ratio, either given or calculated. Results: The studies were categorized by introduction of the author, demographic data in each study, prostate cancer-relatived information, VEGF cut-off value, VEGF subtype, methods of hazard ratio (HR) estimation and its 95% confidence interval (CI). High VEGF-expression in prostate cancer is a poor prognostic factor with statistical significance for OS (HR=2.32, 95%CI: 1.40-3.24). However, high VEGF-expression showed no effect on poor PFS (HR=1.30, 95%CI: 0.88-1.72). Using Begg's, Egger's test and funnel plots, we confirmed lack of publication bias in our analysis. Conclusion: VEGF might be regarded as a prognostic maker for prostate cancer, as supported by our meta-analysis. To achieve a more definitive conclusion enabling the clinical use of VEGF in prostate cancer, we need more high-quality interventional original studies following agreed research approaches or standards.

Representation of the Body in Fashion -Focusing on the Representation of Physicality- (복식에 표현된 몸의 재현성[I] -몸의 사실성 재현을 중심으로-)

  • Yim, Eun-Hyuk;Kim, Min-Ja
    • Journal of the Korean Society of Costume
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    • v.56 no.7 s.107
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    • pp.126-141
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    • 2006
  • Clothes and human body are inseparably related. Aesthetic consciousness of the body determines the form of clothing, reflecting the time and culture as well as the individual and society. Clothes can even reorganize the meaning of the body, while transcending their instrumental functions of protecting, expanding and deforming the body. Using 'body' to analyze the clothing farm, my study develops a framework by which to classify the representation of the body in fashion focusing on the representation of physicality. In order to inquire the formative style and aesthetic values expressed in representing body in fashion, my study examines subjects from the 14th century European costumes to fashion collections of the 20th century. In fashion, representation of the body is visually analogous to the ideal body shape and structure, including a realistic presentation of the body as well as reflection of aesthetic ideals. Representation of physicality refers to structural designs and elastic fabrication. Structural designs appeared in tailoring and bias-cut draping, as well as in stretchy clothes such as Lycra body suit and knit garments that highlights the body structure and movements of the body joints. In representing physicality in fashion, clothing forms reflect body silhouette and each body parts. Therefore, the shape of clothes (signifiant) corresponds to the anatomy and movement of the body ($signifi\'{e}$) in pursuit of aptness. Aesthetic ideal of the body is visualized in the form of a dress. Some clothes prioritize the body, particularly the feminine bodily curves, while others focus on the clothing itself as abstract and sculptural forms. Fashion continues to explore forms and images that transcend the traditional representations of the clothed body. As a type of intimate architecture, fashion always mediates the dialogue between clothes and body, or fashion and figure. My study suggests a framework to analyze bodily representation in fashion, focusing on the relationship between the clothes and body.

Skin Thickness of the Anterior, Anteromedial, and Anterolateral Thigh: A Cadaveric Study for Split-Skin Graft Donor Sites

  • Chan, Jeffrey C.Y.;Ward, John;Quondamatteo, Fabio;Dockery, Peter;Kelly, John L.
    • Archives of Plastic Surgery
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    • v.41 no.6
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    • pp.673-678
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    • 2014
  • Background The depth of graft harvest and the residual dermis available for reepithelization primarily influence the healing of split-skin graft donor sites. When the thigh region is chosen, the authors hypothesize based on thickness measurements that the anterolateral region is the optimal donor site. Methods Full-thickness skin specimens were sampled from the anteromedial, anterior, and anterolateral regions of human cadavers. Skin specimens were cut perpendicularly with a custom-made precision apparatus to avoid the overestimation of thickness measurements. The combined epidermal and dermal thicknesses (overall skin thickness) were measured using a digital calliper. The specimens were histologically stained to visualize their basement membrane, and microscopy images were captured. Since the epidermal thickness varies across the specimen, a stereological method was used to eliminate observer bias. Results Epidermal thickness represented 2.5% to 9.9% of the overall skin thickness. There was a significant difference in epidermal thickness from one region to another (P<0.05). The anterolateral thigh region had the most consistent and highest mean epidermal thickness ($60{\pm}3.2{\mu}m$). We observed that overall skin thickness increased laterally from the anteromedial region to the anterior and anterolateral regions of the thigh. The overall skin thickness measured $1,032{\pm}435{\mu}m$ in the anteromedial region compared to $1,220{\pm}257{\mu}m$ in the anterolateral region. Conclusions Based on skin thickness measurements, the anterolateral thigh had the thickest epidermal and dermal layers. We suggest that the anterolateral thigh region is the optimal donor site for split-skin graft harvests from the thigh.

Electromagnetic Field Exposure and Male Breast Cancer Risk: A Meta-analysis of 18 Studies

  • Sun, Jing-Wen;Li, Xiao-Rong;Gao, Hong-Yu;Yin, Jie-Yun;Qin, Qin;Nie, Shao-Fa;Wei, Sheng
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.1
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    • pp.523-528
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    • 2013
  • Background: The possibility that electromagnetic fields (EMF) exposure may increase male breast cancer risk has been discussed for a long time. However, arguments have been presented that studies limited by poor quality could have led to statistically significant results by chance or bias. Moreover, data fo the last 10 years have not been systematically summarized. Methods and Results: To confirm any possible association, a meta-analysis was performed by a systematic search strategy. Totals of 7 case-control and 11 cohort studies was identified and pooled ORs with 95% CIs were used as the principal outcome measures. Data from these studies were extracted with a standard meta-analysis procedure and grouped in relation to study design, cut-off point, exposure assessment method, adjustment and exposure model. A statistical significant increased risk of male breast cancer with EMF exposure was defined (pooled ORs = 1.32, 95% CI = 1.14-1.52, P < 0.001), and subgroup analyses also showed similar results. Conclusions: This meta-analysis suggests that EMF exposure may be associated with the increase risk of male breast cancer despite the arguments raised.

A Study on the Wear comfort and the Wearing Effects of Maternity Girdles (시판 임산부용 거들의 착용감 및 착용효과에 관한 연구)

  • 최혜선
    • Journal of the Korean Home Economics Association
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    • v.29 no.3
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    • pp.11-21
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    • 1991
  • The study has been intended to find out meaningful information about the development of a prototype of enhanced maternity girdle. The girdles of three different models which were available in the market have been carried out by three six-month pregnant women and three nine-month pregnant women. The results of the study are as follows. 1. All three girdles showed improved wear effects in order of model A, model B, model C. Body surface area measurement and two body surface angles of abdomen are significantly dicreased by wearing and type of girdles. It is presumed that the reasons of good wear effect of model A is low expansion rate of the material and tight fitness of the model. Model B is made of material whose expansion rate is higher than model A. Also abdominal part of the model B is bias cut which is considered to result better stretch and consequently lower wear effect. 2. For wear comfort, subjects preferred in order of model B, model C, and model A. All subjects feel more comfortable after wearing girdles 30 minutes than after wearing girdles 1 day. Comparing 2 subject groups, 6-month pregnant group feel more comfortable about wearing girdles than 9-month pregnant group. 3. The girdles are expanded as a whole in order of model B, model C and model A. Considering the expansion rate of some specific area of the girdles, abdominal area expands more than hip area which expands more than thigh area. The expansion rates of girdles worn to 6-month pregnant group are very low at all area, while the expansion rates of girdles worn to 9-month pregnant group are very high.

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Mechanical Properties Change of the Slacks Knee Part by the Bending Time (굽힘반복에 따른 슬랙스 무릎부위의 역학적특성 변화)

  • Lee, Joung-Suk;Kwon, Hyun-Sun;Sung, Su-Kwang
    • Fashion & Textile Research Journal
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    • v.6 no.4
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    • pp.497-502
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    • 2004
  • The mechanical properties of jean slacks to the type of cutting lines in knee region and the bending time, after doing bending 0 times, 500 times, and 1500 times, the effects of whether or not cutting line, the fabric direction of the cutting area, and the number of cutting lines were investigated for tensile, shearing, compression, and mixing value of mechanical properties. The results are as follows: EM to bending times were larger in order of weft