• 제목/요약/키워드: splitting of subject

검색결과 19건 처리시간 0.029초

산/염기 제조를 위한 바이폴라막의 물분해 특성 연구 (A Study on water-splitting characteristics of bipolar membranes for acid/base generation)

  • 강문성;문승현;이재석
    • 한국막학회:학술대회논문집
    • /
    • 한국막학회 1998년도 추계 총회 및 학술발표회
    • /
    • pp.75-78
    • /
    • 1998
  • 1. Introduction : The clean technology using ion exchange membranes have drawn attention increasingly with advancement of the membrane synthesis. Ion exchange membranes have been used for diffusion dialysis, electrodialysis, electrodialytic water splitting and electrodeionization. Bipolar membranes(BPM), consisting of a cation exchange layer and an an_ion exchange layer, can convert a salt to an acid and a base without chemical addition. Using the bipolar membrane, a large quantity of industrial wastes containing salts can be reprocessed to generate acids and bases. Recent development of high performance bipolar membranes enables to further expand the potential use of electrodialysis in the chemical industry. The water-splitting mechanism in the bipolar membrane, however, is a controversial subject yet. In this study bipolar membranes were prepared using commercial ion exchange membranes and hydrophilic polymer as a binder to investigate the effects of the interface hydrophilicity on water-splitting efficiency. In addition, the water splitting mechanism by a metal catalyst was discussed.

  • PDF

원자력의 고온 핵열을 이용한 열화학적 수소제조 프로세스에의 분리막 기술의 응용 (Application of the Membrane Technology in Thermochemical Hydrogen Production Process using High Temperature Nuclear Heat)

  • 황갑진;박주식;이상호;최호상
    • 한국막학회:학술대회논문집
    • /
    • 한국막학회 2003년도 추계 총회 및 학술발표회
    • /
    • pp.25-33
    • /
    • 2003
  • 원자력 발전의 고온 가스로(high temperature gas-cooled reactor, HTGR)의 냉각제로 사용되는 He가스의 폐열에너지를 이용하여 물을 분해해서 수소를 생산하는 “열화학적 수소제조 IS프로세스”에서의 분리막 기술의 응용에 대해 정리하였다. 고온 원자력 열에너지를 이용한 열화학적 수소 제조법은 실현 가능한 단계까지 왔다고 생각되며, 아직 연구 개발 과제가 많이 남아 있지만, 미래의 청정에너지 중의 하나인 수소를 대량 생산할 수 있는 가능성을 갖고 있다.

  • PDF

원자력 고온 핵 열을 이용한 열화학적 수소제조 IS(요오드-황) 프로세스에서의 분리막 기술의 이용 (Application of Membrane Technology in Thermochemical Hydrogen Production IS (iodine-sulfur) Process Using the Nuclear Heat)

  • 황갑진;박주식;이상호;김태환;최호상
    • 멤브레인
    • /
    • 제14권3호
    • /
    • pp.185-191
    • /
    • 2004
  • 원자력 발전의 고온 가스로(high temperature gas-cooled reactor, HTGR)의 냉각제로 사용되는 He가스의 열에너지를 이용하여 물을 분해해서 수소를 생산하는 "열화학적 수소제조 IS프로세스"에 대해 설명하였다. 특히, 분리막 기술의 이용에 관한 연구를 중점으로 정리하였다. 고온 원자력 열에너지를 이용한 열화학적 수소 제조법은 실현 가능한 단계까지 왔다고 생각되며, 아직 연구 개발 과제가 많이 남아 있지만, 미래의 청정에너지 중의 하나인 수소를 대량 생산할 수 있는 가능성을 갖고 있다.

한국어 복합문에서의 제로 대용어 처리를 위한 분해 알고리즘과 복원규칙 (Splitting Algorithms and Recovery Rules for Zero Anaphora Resolution in Korean Complex Sentences)

  • 김미진;박미성;구상옥;강보영;이상조
    • 한국정보과학회논문지:소프트웨어및응용
    • /
    • 제29권10호
    • /
    • pp.736-746
    • /
    • 2002
  • 한국어에는 복합문에서 영 대용이 빈번하게 발생하여 해석을 어렵게 한다. 따라서 본 논문에서는 한국어 영 대용어 처리를 위해 복합문 분해 알고리즘과 복합문 영 대용어 복원 규칙을 제안하고, 해결방법을 제시한다. 본 논문은 신문 기사의 복합문 중에서 보조용언 내포문을 제외한 인용문, 접속문, 내포문을 처리 대상으로 한다. 복합문 분해를 위해서는 복합문 구성에 관여하는 어미들의 어미 분류표를 이용하고, 영 대용어 복원을 위해서는 생략될 때 적용된 통사규칙을 역으로 이용한다. 인용문은 주어 인칭제약에 따른 동일 명사구 탈락규칙을, 명사화 내포문은 동일 명사구 탈락규칙을, 관형화 내포문은 관계 명사구 탈락규칙을 그리고 접속문은 접속 삭감규칙을 역으로 이용하여 처리한다. 제안한 방법을 이용한 결과 전체 영 대용어 중 83.53%가 해결 가능하며 11.52%는 부분적으로 해결 가능하다.

고강도 전단 보강근과 비폐쇄형 보강근의 혼용에 의한 RC보의 보강 효과 (U-shaped reinforcement for bond splitting prevention in RC beams)

  • 곽성근;이현아;윤혜선;김길희
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2006년도 추계 학술발표회 논문집
    • /
    • pp.201-204
    • /
    • 2006
  • The shear resistance of RC beams is subject to the amount of shear-reinforcing bars ($p_w$) and yield strength ($f_{wy}$) as well as their interactive influence ($p_wf_{wy}$). Thus, it is reasonably expected that high-strength steel bars can greatly reduce the necessary amount of shear-reinforcing bars. On the other hand, although the bond strength is influenced by the amount of shear reinforcing bars, it is not affected by the yield strength. Thus, there is often an issue that bond failure occurs before shear failure depending on the arrangement of shear reinforcing bars. It is a common practice to set sub-ties for the transverse confinement of the main re-bars as a method to prevent the bond failure. However, it can also become a factor in decreased work efficiency due to the complexity of the construction. This study experimented with simultaneous use of high-strength transverse reinforcing bars ($f_{wy}=800MPa$) and U-shaped transverse reinforcing bars of regular strength ($f_{wy}=300MPa$) in an attempt to decrease the necessary quantity of shear reinforcing bars. The effect of this attempt was investigated through fundamental experimental research in terms of the improvement in shear resistance and bond strength as well as the ease of construction.

  • PDF

Robust Transceiver Designs in Multiuser MISO Broadcasting with Simultaneous Wireless Information and Power Transmission

  • Zhu, Zhengyu;Wang, Zhongyong;Lee, Kyoung-Jae;Chu, Zheng;Lee, Inkyu
    • Journal of Communications and Networks
    • /
    • 제18권2호
    • /
    • pp.173-181
    • /
    • 2016
  • In this paper, we address a new robust optimization problem in a multiuser multiple-input single-output broadcasting system with simultaneous wireless information and power transmission, where a multi-antenna base station (BS) sends energy and information simultaneously to multiple users equipped with a single antenna. Assuming that perfect channel-state information (CSI) for all channels is not available at the BS, the uncertainty of the CSI is modeled by an Euclidean ball-shaped uncertainty set. To optimally design transmit beamforming weights and receive power splitting, an average total transmit power minimization problem is investigated subject to the individual harvested power constraint and the received signal-to-interference-plus-noise ratio constraint at each user. Due to the channel uncertainty, the original problem becomes a homogeneous quadratically constrained quadratic problem, which is NP-hard. The original design problem is reformulated to a relaxed semidefinite program, and then two different approaches based on convex programming are proposed, which can be solved efficiently by the interior point algorithm. Numerical results are provided to validate the robustness of the proposed algorithms.

대칭용량 달성을 위한 극 퀀텀 채널 코딩 (Polar Quantum Channel Coding for Symmetric Capacity Achieving)

  • 양재승;박주용;이문호
    • 전자공학회논문지
    • /
    • 제50권8호
    • /
    • pp.3-14
    • /
    • 2013
  • 본 논문에서는 어떠한 이진 입력 이산 퀀텀채널(quantum channel)이 주어지더라도 대칭 용량을 달성할 수 있는 qubit(quantum bit)를 생성하기 위해, 극(polar) 퀀텀 채널 코딩이라 부르는 퀀텀 채널의 결합과 분리 형태를 제시한다. 현재의 용량은 동등 확률을 갖는 임의의 qubit 입력에 따라서 결정된다. 퀀텀채널의 분극은 대칭채널이 1에 근접하면 rate 1로 아니면 rate 0으로 전송하는 채널을 통해 퀀텀 데이터를 부분적으로 전송하는 퀀텀 오류정정 부호화에 아주 적합하다.

치조능확장골절단술을 이용한 임프란트 식립술의 유용성 평가 (Evaluation of the Availability of Implant placement using Ridge Expansion Osteotomy (REO))

  • 김영균;윤필영;김범수
    • 대한치과의사협회지
    • /
    • 제46권4호
    • /
    • pp.243-247
    • /
    • 2008
  • Purpose : Ridge expansion osteotomy (REO) has been introduced when it is necessary to expand narrow crestal ridge with simultaneous implant placement. This study has designed to evaluate the clinical availability of REO. Materials and methods : Subject were patients who had visited Seoul National University Bundang Hospital from July. 2003 to December, 2005 for implant placement using REO by one surgeon. Intraoperative and postoperative complication, failure of initial osseointegration and marginal bone resorption were estimated using electronic medical record and periapical radiography. Twenty?three patients, 8 males and 15 females, mean age 51, ranged 18 to 72, were treated for mean 26 months, ranged from 16 months to 46 months. Results : Mean diameter and length of implants placed at upper anterior, were 3.72mm and 13.32mm each other. Guided bone regeneration and ridge splitting were accompanied in this study. Five cases of cortical bone fracture, three cases of crestal bone loss more than 2mm, 2cases of gingival recession, and 2 cases of infection were noted, but there were no implants removed because of disintegration. Success rate of implant was 91.7%, even if survival rate of implant was 100%. In addition, there were no statistical significance between the success rate of REO and bone graft(p>0.05). Conclusion : Based on the results of the present study, it can be concluded that REO technique is reliable for implant placement at atrophic ridge with adequate height compared to bone graft and other osteotomies for ridge expansion, but care should be taken of esthetic problem such as gingival recession because of crestal bone resorption from trauma by osteotome.

  • PDF

Minimize Web Applications Vulnerabilities through the Early Detection of CRLF Injection

  • Md. Mijanur Rahman;Md. Asibul Hasan
    • International Journal of Computer Science & Network Security
    • /
    • 제23권2호
    • /
    • pp.199-202
    • /
    • 2023
  • Carriage return (CR) and line feed (LF), also known as CRLF injection is a type of vulnerability that allows a hacker to enter special characters into a web application, altering its operation or confusing the administrator. Log poisoning and HTTP response splitting are two prominent harmful uses of this technique. Additionally, CRLF injection can be used by an attacker to exploit other vulnerabilities, such as cross-site scripting (XSS). Email injection, also known as email header injection, is another way that can be used to modify the behavior of emails. The Open Web Application Security Project (OWASP) is an organization that studies vulnerabilities and ranks them based on their level of risk. According to OWASP, CRLF vulnerabilities are among the top 10 vulnerabilities and are a type of injection attack. Automated testing can help to quickly identify CRLF vulnerabilities, and is particularly useful for companies to test their applications before releasing them. However, CRLF vulnerabilities can also lead to the discovery of other high-risk vulnerabilities, and it fosters a better approach to mitigate CRLF vulnerabilities in the early stage and help secure applications against known vulnerabilities. Although there has been a significant amount of research on other types of injection attacks, such as Structure Query Language Injection (SQL Injection). There has been less research on CRLF vulnerabilities and how to detect them with automated testing. There is room for further research to be done on this subject matter in order to develop creative solutions to problems. It will also help to reduce false positive alerts by checking the header response of each request. Security automation is an important issue for companies trying to protect themselves against security threats. Automated alerts from security systems can provide a quicker and more accurate understanding of potential vulnerabilities and can help to reduce false positive alerts. Despite the extensive research on various types of vulnerabilities in web applications, CRLF vulnerabilities have only recently been included in the research. Utilizing automated testing as a recurring task can assist companies in receiving consistent updates about their systems and enhance their security.