Enhanced conversion efficiency of crystalline Si solar cells via luminescent down-shifting using Ba2SiO4 : Eu2+ phosphor

Wen Bin Hung,Juyn Ye Chen,Kien Wen Sung,Teng Ming Chen 한양대학교 세라믹연구소 2014 Journal of Ceramic Processing Research Vol.15 No.3

The colloidal submicron needle-like Ba2SiO4 : Eu2+ phosphor coated on microtextured silicon surface has been used as a luminescent down-shifting (LDS) material for enhancing the power conversion efficiency of solar cells. Under a simulated onesun illumination, upon phosphor coating the solar cells showed an enhancement of the short-circuit current density (Jsc) increased from 34.00 to 34.48 mA/cm2 , meanwhile the power conversion efficiency (PCE) was enhanced from 15.13% to 15.36%. The related underlying mechanism for these enhancements can be attributed to photon down-shifting and light scattering effect through the investigation of PLE spectrum, reflectance, and external quantum efficiency. Our results indicate that the colloidal submicron needle-like Ba2SiO4 : Eu2+ phosphor not only act as LDS centers in the UV region but also serve as an antireflection coating for enhancing the light absorption in the visible regime.

White Spot Syndrome Virus Disease of Shrimp and Diagnostic Methods

Wen-Bin Zhan 한국수산과학회 양식분과 2002 韓國養殖學會誌 Vol.15 No.1

웹 기반 수준진단 시스템을 통한 맞춤형 생산정보화 도입 가이드라인에 관한 연구

Wen-Bin Zhao,이주연(Ju Yeon Lee),노상도(Sang Do Noh),조현제(Hyun Jei Jo),조용주(Yong Ju Jo),최석우(Seog Ou Choi) (사)한국CDE학회 2011 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2011 No.1

제조기업이 생산정보화시스템(MES) 도입 시, 기업별로 생산환경의 특성이 모두 반영된 정보화로 추진되어야 하는 관계로 대기업과는 달리 중소기업에서 도입하는 데에 많은 어려움을 겪고 있다. 일반적으로 국내의 중소형 제조기업에서 MES 를 도입할 때 기업의 생산환경 특성을 반영하는 업종이나 규모, 생산방식 및 주문방식 등 요소를 고려하지 않고 획일적인 전략을 기반으로 도입을 하고 있으며, 이로 인해 도입 후에도 시스템이 제대로 활용되지 못하고 일부의 간단한 기능만을 사용하게 되거나, 이로 인한 사용자의 만족도가 낮아지는 등의 많은 문제점이 발생하고 있다. 본 논문에서는 생산정보화시스템(MES)의 효율적인 도입을 위해 웹 기반의 정보화 수준 진단시스템을 이용한 생산정보화의 보급/확산 전략을 도출한다. 또한 웹 포털 상에서 이해하기 쉽고 간단한 대화형식의 질문을 통해 해당 기업의 수준과 필요를 도출하여 맞춤형 생산정보화시스템(MES) 도입 가이드라인을 제시한다.

Dynamic Analysis and Design Calculation Methods for Powertrain Mounting Systems

Wen-Bin Shangguan,Zhao Yinyan 한국자동차공학회 2007 International journal of automotive technology Vol.8 No.6

A method for dynamic analysis and design calculation of a Powertrain Mounting System (PMS) including Hydraulic Engine Mounts (HEM) is developed with the aim of controlling powertrain motion and reducing low-frequency vibration in pitch and bounce modes. Here the pitch mode of the powertrain is defined as the mode rotating around the crankshaft of an engine for a transversely mounted powertrain. The powertrain is modeled as a rigid body connected to rigid ground by rubber mounts and/or HEMs. A mount is simplified as a three-dimensional spring with damping elements in its Local Coordinate System (LCS). The relation between force and displacement of each mount in its LCS is usually nonlinear and is simplified as piecewise linear in five ranges in this paper. An equation for estimating displacements of the powertrain center of gravity (C.G.) under static or quasi-static load is developed using Newton’'s second law, and an iterative algorithm is presented to calculate the displacements. Also an equation for analyzing the dynamic response of the powertrain under ground and engine shake excitations is derived using Newton’'s second law. Formulae for calculating reaction forces and displacements at each mount are presented. A generic PMS with four rubber mounts or two rubber mounts and two HEMs are used to validate the dynamic analysis and design calculation methods. Calculated displacements of the powertrain C.G. under static or quasi-static loads show that a powertrain motion can meet the displacement limits by properly selecting the stiffness and coordinates of the tuning points of each mount in its LCS using the calculation methods developed in this paper. Simulation results of the dynamic responses of a powertrain C.G. and the reaction forces at mounts demonstrate that resonance peaks can be reduced effectively with HEMs designed on the basis of the proposed methods.

Simulated Annealing Utilization for Intelligent Reflecting Surfaces

Wen-Bin Li,Thu L. N. Nguyen,Yoan Shin 한국통신학회 2021 한국통신학회 학술대회논문집 Vol.2021 No.6

In this paper, we first formulate the path loss model of an intelligent reflecting surface (IRS) in terms of IRS reflection coefficients, then adopt a simulated annealing algorithm to determine a global maximum point of the path loss. Consequently, we can improve the performance of IRS-assisted communication system by avoiding such position deviations in practice. Simulation results show that an optimal solution can be achieved by implementing the proposed algorithm.

지속가능 엔지니어링을 위한 PLM 시스템의 개념 설계에 관한 연구

Wen-Bin Zhao,노상도(Sang Do Noh) (사)한국CDE학회 2012 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2012 No.2

PLM, Product Lifecycle Management 는 초기 제품 기획 단계인 고객 요구사항 파악에서부터 유지관리, 복구의 마지막 단계까지 제품의 전 라이프 사이클에 걸쳐 관련된 정보를 통합적으로 관리하는 것으로, 신속한 제품 개발과 협업 달성 등 제조업이 당면한 다양한 요구를 만족시킬 수 있는 새로운 패러다임이다. 일반적으로 PLM 에서는 제조과정에서 발생 가능한 문제점을 사전에 파악하여 비용과 시간을 최소화하고, 기술과 서비스 지원을 통한 생산성 향상을 추구하고 있다. 그러나, 근래에 들어 산업화 이후 문명을 지탱하고 있는 자원의 일방적 채취와 소비가 더 이상 인간의 번영을 보장 할 수 없다는 인식이 확산되고 있으며, 화석 연료를 기반으로 하는 직선적인 생산 및 소비 형태의 한계와 문제점이 드러나고 있다. 그 결과 저탄소 녹색성장, 청정생산, 친환경 제품 등의 이슈화가 본격적으로 진행되고 있으며, 제조 기업에서도 지속가능한 발전은 향후 산업 발전의 주요한 추진 방향으로 잡게 되었다. 본 논문에서는 제조 기업에서 기존의 제품, 생산 엔지니어링과 함께 지속가능 엔지니어링 수행을 지원하는 새로운 PLM 의 정보모델을 연구하였으며, PLM 시스템의 개념 설계를 진행하였다.

Differential antioxidation activities in two alfalfa cultivars under chilling stress

Wen-Bin Wang,김윤희,Haeng-Soon Lee,Xi-Ping Deng,Sang-Soo Kwak 한국식물생명공학회 2009 Plant biotechnology reports Vol.3 No.4

To understand the adaptability of alfalfa (Medicago sativa L.) to chilling stress, we analyzed the antioxidative mechanism during seed germination. The germination rates of six alfalfa cultivars were studied comparatively at 10C. Xinmu No. 1 and Northstar were selected as chilling stress-tolerant and stress-sensitive cultivars for further characterization. After chilling treatment, Xinmu No. 1 showed higher seedling growth than Northstar. Xinmu No. 1 exhibited low levels of hydrogen peroxide and lipid peroxidation compared with Northstar. In addition, shoots in Xinmu No. 1 treated with chilling showed higher activities of the superoxide dismutase, ascorbate peroxidase (APX), and catalase than those of Northstar, whereas Xinmu No. 1 showed higher APX activity in roots that Northstar. These results indicated that high antioxidation activity in Xinmu No. 1 under chilling stress is well associated with tolerance to chilling condition during germination.

Research on the Correlation between Wavy Modeling of Garment and Fabric Properties

( Wen Bin Zhang ),( Wu Tuo ),( Jing Ru Liu ) 한국패션비즈니스학회 2004 패션 비즈니스 Vol.8 No.6

On the basis of garment spatial configuration technology, the correlation of fabric properties and garment modeling was studied in this paper. With abundant experimental data, practical modeling and the judgment of fabric properties and physical shape, we analyzed the change rules that restricting all kinds of parameters of fabric properties and garment modeling, and discussed the relation of wavy modeling and all correlated factors of fabric properties. The result showed the basis of choosing fabric for different style garment, which would help designers choosing fabric for modeling design or structure design.

Use Chains to Block DNS Attacks: A Trusty Blockchain-based Domain Name System

Wen-Bin Hsieh,Jenq-Shiou Leu,Jun-Ichi Takada 한국통신학회 2022 Journal of communications and networks Vol.24 No.3

The Internet has become one of the most importanttechnologies in the world, and hackers use various methods tolaunch cyber attacks to profit from it. Phishing is one of famoussocial engineering attacks, it is often used to steal user data,including login credentials and credit card numbers. Althoughthe Transport Layer Security certificate is used to verify the trustof websites, there are still a series of vulnerabilities. The demandfor trusted IP addresses has led a lot of research, including IPwhitelisting, DNS filtering and so on. However, these technologiesstill have many shortcomings. In view of this, we proposeda novel mechanism for verifying websites using blockchaintechnology. The URL and IP address of a permissioned websiteare recorded in blockchain through a specific smart contract. A DNS query is executed through a smart contract designedto avoid URL redirection attacks. With the help of immutablenature of blockchian, phishing websites can be detected. Themechanism will not add any load to users and provides tamperprooffunctions based on the characteristics of blockchain. Thecomparison of related works shows that the proposed mechanismis more secure. We also provided a reference implementationof the proposed mechanism on Ethereum Quorum simulationplatform, which proves the effectiveness and practicability of themechanism.

Fault Diagnosis Model Based on Multi-level Information Fusion for CNC Machine Tools

Wen Yan,Tan Ji-wen,Zhan Hong,Sun Xian-bin 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.8

The difficulty of CNC machine tools fault diagnosis is bigger than other general equipments because of the complex structure and the coupling among subsystems. The fault diagnosis model based on multi-level information fusion and hybrid intelligence is studied to improve reliability of fault diagnosis. Information from built-in sensors is used to monitor the status of CNC machine tools. The diagnosis principles of internal parameters-motor current, torque, temperature and following error are analyzed. Internal information and external sensors are two main sources which provide data to diagnosis. In order to detect effective fault signal, features of time domain, frequency domain and time-frequency domain are extracted. All these features constitute the feature set. The features are selected by the method of Kernel Principal Component Analysis (KCPA). Then the sensitive feature set is obtained. The method of multiple classifier fusion based on fuzzy comprehensive evaluation is researched. The determination method of weight based on information entropy is proposed. This diagnosis model has been tested feed system mechanical fault diagnosis of CNC machine tools and the results show which is effective and versatile.