• Title/Summary/Keyword: selective

Search Result 8,046, Processing Time 0.037 seconds

Effects of Surface Homogeneity on Optical Properties of Sputter-deposited AlTiO Selective Transmitting Layers (스퍼터 증착으로 형성된 AlTiO 선택적 투과막의 표면 균질성에 따른 광학적 특성)

  • Jeong, So-Un;Lim, Jung-Wook;Lee, Seung-Yun
    • Journal of the Korean Vacuum Society
    • /
    • v.21 no.1
    • /
    • pp.22-28
    • /
    • 2012
  • Transparent dye-sensitized solar cells have been widely investigated for the application to building integrated photovoltaic system. Thin film Si-based solar cells are emerging as a substitute for the dye-sensitized solar cells because their merits of well-established manufacturing processes. Since the selective transmitting layer transmits visible light and reflects infrared light, the solar cell efficiency increases with the introduction of the selective transmitting layer. In this work, AlTiO thin films were grown as the selective transmitting layer by cost-effective sputter deposition and their transmittances were improved by controlling deposition parameters.

A Selective Feedback LNA Using Notch Filter in $0.18{\mu}m$ CMOS (노치필터를 이용한 CMOS Selective 피드백 저잡음 증폭기)

  • Seo, Mi-Kyung;Yun, Ji-Sook;Han, Jung-Won;Tak, Ji-Young;Kim, Hye-Won;Park, Sung-Min
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.46 no.11
    • /
    • pp.77-83
    • /
    • 2009
  • In this paper, a selective feedback low-noise amplifier (LNA) has been realized in a $0.18{\mu}m$ CMOS technology to cover a number of wireless multi-standards. By exploiting notch filter, the SF-LNA demonstrates the measured results of the power gain (S21) of 11.5~13dB and the broadband input/output impedance matching of less than -10dB within the frequency bands of 820~960MHz and 1.5~2.5GHz, respectively. The chip dissipates 15mW from a single 1.8V supply, and occupies the area of $1.17\times1.0mm^2$.

Channel Estimation Method Using the Correlation in the High-Speed Wireless Transmissions (고속 무선 전송에서 상관관계를 이용한 채널 추정방식)

  • Lee Joo-Hyoung;Kim Joo-Kyoung;Kim Jae-Moung
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.4 no.1 s.6
    • /
    • pp.63-71
    • /
    • 2005
  • This paper proposes the channel estimation method robust to severe frequency selective fading channels in O%M system using wide bandwidth for the high data rate transmission. DDCE, which uses data between the high correlated symbols, is usually used for channel estimation in the slow fading channels. DDCE can get high gains in the non-selective channels. As the bandwidth of system gets wider, it becomes more severe frequency selective fading environments so that the reliability of data becomes lower and error flow is occurred. FE method, this paper proposed, uses the relation between sub-carriers of OFDM in frequency selective fading channels so FE method gets some gains by adapting the power value at a target frequency to the mean value of channel estimated values of adjacent sub-carriers. Because FE uses only preamble unlike DDCE using data, it is independent of data rate related to the reliability of data and the number of multipath. Consequently, FE can obtain considerable gains in the wideband systems where the errorflow of DDCE is occurred, and FE is applicable to frequency selective fading environments.

  • PDF

Thermal Residual Stresses and Spring back Effects on the Frequency Selective Surface Embedded Composite Laminates (주파수 선택막이 삽입된 복합재 평판의 잔류 열응력과 스프링 백 효과)

  • Park, Kyoung-Mi;Seo, Yun-Seok;Chun, Heoung-Jae;Hong, Ic-Pyo;Park, Yong-Bae;Kim, Yun-Jae
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.26 no.6
    • /
    • pp.475-481
    • /
    • 2013
  • The residual stresses occur in the Frequency Selective Surface(FSS) embedded hybrid composite structures after co-curing due to mismatch among the coefficient of thermal expansions and stiffness values between the FSS and composite materials. The spring backs occur due to these residual stresses. Therefore, in this paper, the spring-backs caused by residual stresses in FSS embedded composite structures were studied with considering effect of symmetric and unsymmetric stacking sequence of composite laminates.

Production of Ni-Cr Metal Powder by Selective Laser Melting for Dentistry to Observation of Characteristics (치과 SLM용 Ni-Cr 금속분말 특성 관찰)

  • Hong, Minho
    • Journal of Technologic Dentistry
    • /
    • v.37 no.1
    • /
    • pp.23-29
    • /
    • 2015
  • Purpose: The selective laser melting (SLM) process for dentistry, which is one of the additive manufacturing technologies (AM) allows for rapid production of a three-dimensional model with complex shape by directly melting metal powder. This process generates detailed items of a three-dimensional model shape through consolidation of a thin powder layer by utilizing both selective melting and laser beam simultaneously. In regard to SLM process, Fe-base powder, Ti-6AI-4V powder, AI-base powder, etc. have been researched. It is believed that the aforementioned technologies will be widely utilized in manufacturing metal parts using metal powder of raw material. This study chose Ni-Cr-Mo metal powder in order to manufacture metal powder materials that would be used in the selective laser melting for dentistry. Methods: This study manufactured metal powder using mechanical alloying technique (MA) among those metal powder manufacturing techniques. Moreover, this study aimed to utilize the metal powder manufactured after observing the characteristics of powder as preliminary data of Ni-Cr-Mo metal powder. This study could obtain the following conclusions within the experimental limitations. Results: As a result of mechanically alloying Ni-Cr-Mo powder over time, its mean particle size was $66.93{\mu}m$ $54.4{\mu}m$ and $45.39{\mu}m$ at 10h, 20h and 30h, respectively. The gtain form of metal powder by mechanical alloying technique was a sponge-like shape of irregular plate; however, the gtain form manufactured by high-pressure water aromization process had the following three types: globular type, chain type and oval type. Conclusion: This study found $37.65{\mu}m$ as the mean particle size of Ni-Cr-Mo metal powder, which was manufactured using water atomization technique under the following conditions: water atomization flux of 300 liter/min, hydraulic pressure of $400kgf/cm^2$ and injection angle of $45^{\circ}$. This study confirmed that the grain form of powder (solid particle form) would vary depending on the manufacturing process.

Design and Evaluation of a Fuzzy Logic-based Selective Paging Method for Wireless Mobile Networks (무선 이동망을 위한 퍼지 논리 기반 선택적 페이징 방법의 설계 및 평가)

  • 배인한
    • Journal of KIISE:Information Networking
    • /
    • v.31 no.3
    • /
    • pp.289-297
    • /
    • 2004
  • State-of-the-art wireless communication networks allow dynamic relocation of mobile terminals. A location management mechanism is required to keep track of a mobile terminal for delivering incoming calls. In this paper, we propose a fuzzy logic-based selective paging method to reduce paging cost. In the proposed fuzzy logic-based location management method, the location update uses the area-based method that uses direction-based together with movement-based methods, and the location search uses the fuzzy logic-based selective paging method based on the mobility information of mobile terminals. A partial candidate paging area is selected by fuzzy control rules, then the fuzzy logic-based selective paging method pages only the cells within the partial candidate paging area. The performance of proposed fuzzy logic-based location management method is to be evaluated by both an analytical model and a simulation, and is compared with those of LA and BVP methods. From these evaluation results, we know that the proposed fuzzy logic-based location management method provide better performance than other location management methods.

A Robust Scheme for Emergency Message Delivery in Vehicle Communications on Freeway (고속도로상의 차량간 통신에서 에러에 강한 긴급메시지 전달 기법)

  • Park, Jeong-Seo;Park, Tae-Keun
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.35 no.12A
    • /
    • pp.1113-1121
    • /
    • 2010
  • The Vehicle Safety Communications (VSC) is one of VANET applications for preventing vehicle accidents, and it utilizes vehicle-to-vehicle communication to exchange emergency messages. To propagate such messages in VSC, several schemes based on selective flooding have been proposed. Their common idea is that an emergency message is relayed by one of vehicles receiving the message. However, the schemes do not consider the transmission errors and duplications of an emergency event. In the schemes, if there are transmission errors and a vehicle detects a hazard, there may be vehicles which fail to receive an emergency message. If k vehicles detect a hazard, k emergency messages are created and propagated. The duplications of an event increase reliability of the message delivery but decrease efficiency. In this paper, we propose an emergency message delivery scheme which is efficient and robust to transmission errors. Our proposed scheme utilizes clustering for massage aggregation and retransmissions in a cluster. It also uses an acknowledgment mechanism for reliable inter-cluster communication. Our simulation results show that the proposed scheme outperforms Least Common Neighbor Flooding which is one of the selective flooding schemes.

Roles of Opioid Receptor Subtype in the Spinal Antinociception of Selective Cyclooxygenase 2 Inhibitor

  • Choi, Cheol-Hun;Kim, Woong-Mo;Lee, Hyung-Gon;Jeong, Cheol-Won;Kim, Chang-Mo;Lee, Seong-Heon;Yoon, Myung-Ha
    • The Korean Journal of Pain
    • /
    • v.23 no.4
    • /
    • pp.236-241
    • /
    • 2010
  • Background: Selective inhibitors of cycloosygenase (COX)-2 are commonly used analgesics in various pain conditions. Although their actions are largely thought to be mediated by the blockade of prostaglandin (PG) biosynthesis, evidences suggesting endogenous opioid peptide link in spinal antinociception of COX inhibitor have been reported. We investigated the roles of opioid receptor subtypes in the spinal antionociception of selective COX-2 inhibitor. Methods: To examine the antionociception of a selective COX-2 inhibitor, DUP-697 was delivered through an intrathecal catheter, 10 minutes before the formalin test in male Sprague-Dawley rats. Then, the effect of intrathecal pretreatment with CTOP, naltrindole and GNTI, which are ${\mu}$, $\delta$, and k opioid receptor antagonist, respectively, on the analgesia induced by DUP-697 was assessed. Results: Intrathecal DUP-697 reduced the flinching response evoked by formalin injection during phase 1 and 2 Naltrindole and GNTI attenuated the antinociceptive effect of intrathecal DUP-697 during both phases of the formalin test, CTOP reversed the antinociception of DUP-697 during phase 2, but not during phase 1, Conclusions: Intrathecal DUP-697, a selective COX-2 inhibitor, effectively relieved inflammatory pain in rats. The $\delta$ and $\kappa$ opioid receptors are involved in the activity of COX-2 inhibitor on the facilitated state as well as acute pain at the spinal level, whereas the ${\mu}$ opioid receptor is related only to facilitated pain.

Study of Development of Selective Removal Adsorption Ion Exchange Resin Materials for Fabricated with Chemical-biological Cloth by QFD (QFD 기법을 이용한 특정 유해가스 노출제어 이온선택성 보호복 소재개발연구)

  • Song, Hwa Seon;Koo, Il Seob;Kim, In Sik
    • Journal of Korean Society for Quality Management
    • /
    • v.43 no.3
    • /
    • pp.359-372
    • /
    • 2015
  • Purpose: Through studying the expert's and non-experts panel responses to the questions regarding the attributes of chemical-biological protection cloth quality in terms of the levels of customer demand and technical factors has been studied. We are applied to a QFD matrix with find out the relationship between the selective removal efficiency of chemical-biological cloth and the guidelines of technical approach. Methods: We fabricated several composite of ion-exchange resins with selectively permeable performance designed to facilities water vapor transport and selective adsorption of the harmful gases. With these materials, we characterized on the selectively permeable performance to identify ion-exchange resin with chemical-biological protective cloth. Results: Results showed that ion exchange materials possessed performance with selectively efficiencies as NH3, SOx, NOx and HCl gas. The selective adsorption amount of ammonia and hydrogen gases were $90-80{\mu}g/g$ with TRILITE SCR-BH sulfonated ion exchange resin. The PP non-woven/ion exchange resin adsorbent materials possessed performance with water vapor permeability were 1,100-1,350 g/m2/day, it's was two times high value compare with activated carbon. With these materials, we characterized selectively removal efficiency to identify new ion-exchange material with chemical-biological protective capability. Conclusion: This study shows that a QFD aids in deciding with of the adsorption parameters to optimized with chemical-biological protection cloth manufacturing.

Is Pancapsular Release More Effective than Selective Capsular Release for the Treatment of Adhesive Capsulitis?

  • Moon, Nam Hoon;Lee, Seung-Jun;Shin, Won Chul;Lee, Sang Min;Suh, Kuen Tak
    • Clinics in Shoulder and Elbow
    • /
    • v.18 no.1
    • /
    • pp.28-35
    • /
    • 2015
  • Background: We assessed the effectiveness of arthroscopic capsular release for the treatment of adhesive capsulitis. Further, we tried to ascertain the clinical benefits, if any, of pancapsular release over selective capsular release, where the two differ by performing or not performing a posterior capsular release, respectively. Methods: Thirty-five consecutive patients with either primary or secondary adhesive capsulitis who failed conservative treatment for more than 6 months were enrolled in the study. A total of 16 patients allocated in group 1 received a pancapsular release that comprises the release of the rotator interval, anteroinferior capsular, and the posterior capsular release, whereas 19 patients in group 2 received a selective capsular release that comprises only the release of the rotator interval release and anteroinferior capsular release. The clinical outcomes, visual analogue scale (VAS) score, Constant score, and range of motion, were assessed preoperative and postoperatively. Results: In both groups, the preoperative VAS score, Constant score, and ROM showed a significant improvement by the 6-month follow-up. We found that the immediate postoperative internal rotation was significantly higher in group 1 than group 2. Despite significant differences seen between the two groups at the initial postoperative period, there were no significant differences in Constant score, VAS score, and the ROM at all the subsequent follow-ups between the two groups. Conclusions: Arthroscopic capsular release for the treatment of adhesive capsulitis is very effective. However, pancapsular release did not show any advantage over selective capsular release in terms of overall clinical outcome.