Tandem Solar Cells from Solution-Processed CdTe and PbS Quantum Dots Using a ZnTe–ZnO Tunnel Junction

Crisp, Ryan W.,Pach, Gregory F.,Kurley, J. Matthew,France, Ryan M.,Reese, Matthew O.,Nanayakkara, Sanjini U.,MacLeod, Bradley A.,Talapin, Dmitri V.,Beard, Matthew C.,Luther, Joseph M. American Chemical Society 2017 Nano letters Vol.17 No.2

<P>We developed a monolithic CdTe–PbS tandem solar cell architecture in which both the CdTe and PbS absorber layers are solution-processed from nanocrystal inks. Due to their tunable nature, PbS quantum dots (QDs), with a controllable band gap between 0.4 and ∼1.6 eV, are a promising candidate for a bottom absorber layer in tandem photovoltaics. In the detailed balance limit, the ideal configuration of a CdTe (<I>E</I><SUB>g</SUB> = 1.5 eV)–PbS tandem structure assumes infinite thickness of the absorber layers and requires the PbS band gap to be 0.75 eV to theoretically achieve a power conversion efficiency (PCE) of 45%. However, modeling shows that by allowing the thickness of the CdTe layer to vary, a tandem with efficiency over 40% is achievable using bottom cell band gaps ranging from 0.68 and 1.16 eV. In a first step toward developing this technology, we explore CdTe–PbS tandem devices by developing a ZnTe–ZnO tunnel junction, which appropriately combines the two subcells in series. We examine the basic characteristics of the solar cells as a function of layer thickness and bottom-cell band gap and demonstrate open-circuit voltages in excess of 1.1 V with matched short circuit current density of 10 mA/cm<SUP>2</SUP> in prototype devices.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2017/nalefd.2017.17.issue-2/acs.nanolett.6b04423/production/images/medium/nl-2016-04423k_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl6b04423'>ACS Electronic Supporting Info</A></P>

A Research Review on Mobility Management Protocols over IPv6

Ryan Ercel Paderes,Byungjoo Park 보안공학연구지원센터 2016 International Journal of Software Engineering and Vol.10 No.7

Mobile connection is a rising commodity wherein the demand for it is growing. Because of this, the mobility support for Internet devices is an important factor, since mobile and Internet-based computing is on the rise. Ever since the mobile connectivity was launched years ago, the number of devices designed for such purpose also has also raised sky high. Mobile connection is on a scale that it needs to be further enhanced further because of the massive traffic it handles. Being connected to everything is the utmost importance on mobile connectivity. In this paper a thorough look on the MIPv6 protocol will be discussed, how MIPv6 works as a protocol and problems encountered in this protocol and the developments that were made.

How Governmental Structure Affects Climate Change Policies

Ryan Dash 한국환경정책학회 2016 한국환경정책학회 학술대회논문집 Vol.2016 No.10

Participatory Drama as a Language Teaching Device

Ryan, William E . 한국커뮤니케이션학회 1996 커뮤니케이션학연구 Vol.4 No.1

The Role of Alginate Hydrogels as a Potential Treatment Modality for Spinal Cord Injury: A Comprehensive Review of the Literature

Ryan Jarrah,Sally El Sammak,Chiduziem Onyedimma,Abdul Karim Ghaith,F.M. Moinuddin,Archis R. Bhandarkar,Ahad Siddiqui,Nicolas Madigan,Mohamad Bydon 대한척추신경외과학회 2022 Neurospine Vol.19 No.2

Objective: To comprehensively characterize the utilization of alginate hydrogels as an alternative treatment modality for spinal cord injury (SCI). Methods: An extensive review of the published literature on studies using alginate hydrogels to treat SCI was performed. The review of the literature was performed using electronic databases such as PubMed, EMBASE, and OVID MEDLINE electronic databases. The keywords used were “alginate,” “spinal cord injury,” “biomaterial,” and “hydrogel.” Results: In the literature, we identified a total of 555 rat models that were treated with alginate scaffolds for regenerative biomarkers. Alginate hydrogels were found to be efficient and promising substrates for tissue engineering, drug delivery, neural regeneration, and cellbased therapies for SCI repair. With its ability to act as a pro-regenerative and antidegenerative agent, the alginate hydrogel has the potential to improve clinical outcomes. Conclusion: The emerging developments of alginate hydrogels as treatment modalities may support current and future tissue regenerative strategies for SCI.

Probabilistic Correspondence in Video Sequences for Efficient State Estimation and Autonomous Flight

Ryan, Tyler,Kim, H. Jin IEEE 2016 IEEE TRANSACTIONS ON ROBOTICS Vol. No.

<P>In this paper, we describe a method for using Bayesian inference to create probabilistic point correspondences in video sequences. Using state prior distribution information from the on-board Kalman filter found in most unmanned aerial vehicles, we derive an accurate normal approximation for the movement of points in image space. It is then a direct application of Bayesian inference to find the probability that a feature point found in the current image is the same feature point found in a previous image. The biggest advantage of this method is that it does not require the use of feature descriptors, which can be computationally expensive to compute. The algorithm is tested in two scenarios. The first uses data and images collected from a sample flight to evaluate velocity estimation performance, which is critical for achieving good control. When compared to using a standard matching algorithm based on ORB (oriented FAST and rotate BRIEF) descriptors, our algorithm provides both improved efficiency and accuracy. We then implement the algorithm for online testing as well as develop a simple visual odometry method based on probabilistic correspondences for full state estimation. Flight tests demonstrate fully autonomous indoor hover using only the sensors embedded in the onboard smartphone and sonar.</P>

The Sovereignty Dispute over the Liancourt Rocks between Korea and Japan: An Analysis under the International Public Legal Principles of Sovereignty Acquisition

Ryan Kihoon Kang 서울대학교 아시아태평양법연구소 2013 Journal of Korean Law Vol.12 No.2

The purpose of the article is to determine the territorial sovereignty status of the Liancourt Rocks, disputed between Korea and Japan. The islands are currently occupied and controlled by Korea, and Japan protests the Korean occupation as illegal. The paper employs the historical analysis of the state and civilian actions involving the Liancourt Rocks. The relevant actions are examined under the international legal principles of sovereignty acquisition founded by international mediators, arbitrators, the Permanent Court of International Justice, and the International Court of Justice throughout history. The paper finds that Korea has acquired an earlier title than Japan and has maintained the valid and legal sovereignty over the Liancourt Rocks through the operation of various principles under public international law. Thus the current occupation of the Liancourt Rocks by Korea is found to be legal and valid.

A Meta-Study on the Improvement System of Industry – Academic Cooperation -Focusing on the Industry Perspective -

Ryan Sungpyo Sohn 한국무역금융보험학회(구 한국무역보험학회) 2021 무역보험연구 Vol.22 No.2

4차산업혁명 기술의 대중화 및 일반화와 글로벌 팬더믹 현상의 확산은, 국제무역의 양극화 및 이로 인한 사회적인 패러다임의 변화를 대학 교육과정에까지 그 영향을 깊숙하게 미치고 있다. 이에 대한 선제적인 대응 방안으로서의 산업체 관점의 교육 과정 개선 체계의 구축 필요성과 아울러, 종합적인 산학협력 교육과정의 중장기 역량 강화가 각 대학들의 시급한 문제로 대두 되고 있다. 또한 산업 현장의 요구와 미래 수요를 반영한 교육과정 개편 체계의 도입은 이제 선택이 아니 라 필수로 인식되어지는 뉴 노멀 현상임에 착안하여, 본 논문에서는 교육과정 관련 규정 및 직제 개선 연구와 함께 현장 협력 네트워크를 구축하여, 기존 대학들이 일부 기업들과 상징적 인 산학협력을 진행하였던 구도에서 벗어나, 산업체의 니즈가 반영된 실무능력을 보유한 인적 자원의 원활한 공급에 핵심을 둔 논문들의 메타 분석을 통하여 산학협력 교육과정의 구조적인 개선방안을 제시하였다. Purpose : The popularization and generalization of the 4th Industrial Revolution technology and the spread of the global pandemic are deeply affecting the polarization of international trade and the resulting social paradigm shift to the university curriculum. The purpose of this study is to present problems and improvement measures for the overall improvement system of Industry-Academic cooperation in the university. Research design, data, methodology : Based on previous studies, a Meta-study was conducted on the Industry-Academic cooperation of the universities. Results : In addition to the necessity of establishing a system for improving the curriculum from the perspective of the industry as a preemptive countermeasure, strengthening the mid- to long-term capacity of the comprehensive industry-academic cooperation curriculum is emerging as an urgent problem for each university. Conclusions : In this thesis, by establishing an on-site cooperation network along with research on curriculum-related regulations and organizational improvement, we have deviated from the structure in which existing universities conducted symbolic industry-academic cooperation with some companies, and developed human resources with practical skills reflecting the needs of the industry. A structural improvement plan was suggested through meta-analysis of papers that are key to smooth supply.

Student Note : The Sovereignty Dispute over the Liancourt Rocks between Korea and Japan: An Analysis under the Public International Legal Principles of Sovereignty Acquisition

( Ryan Kihoon Kang ) 서울대학교 법학연구소 2013 Journal of Korean Law Vol.12 No.2

The purpose of the article is to determine the territorial sovereignty status of the Liancourt Rocks, disputed between Korea and Japan. The islands are currently occupied and controlled by Korea, and Japan protests the Korean occupation as illegal. The paper employs the historical analysis of the state and civilian actions involving the Liancourt Rocks. The relevant actions are examined under the international legal principles of sovereignty acquisition founded by international mediators, arbitrators, the Permanent Court of International Justice, and the International Court of Justice throughout history. The paper finds that Korea has acquired an earlier title than Japan and has maintained the valid and legal sovereignty over the Liancourt Rocks through the operation of various principles under public international law. Thus the current occupation of the Liancourt Rocks by Korea is found to be legal and valid.

Trash Detection for Ocean Cleanup Robot using Remotely Operated Vehicle (ROV)

Ryan Febriansyah,Soo Young Shin 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.2