SYNTHESIS OF ULTRAFINE $Si_3N_4$ PARTICLES BY RF PLASMA CHEMICAL VAPOR DEPOSITION

Hongjie, Zhu,Zhu, Yihua,Han, Jinyi,Li, Chunzhong,Hu, Liming 한국재료학회 1995 Fabrication and Characterization of Advanced Mater Vol.1 No.2

Processing of synthesis $Si_3N_4$ UFP in the RFCVD reactor, using $SiCl_4$ and $NH_3$ as precursors, were experimentally researched. The influence of some operation parameters on the properties of products was investigaed. The nanostructured material made of such $Si_3N_4$ particles was fabricated under highpressure. The results of experiments indicated that it differed from the materials made of coarse $Si_3N_4$ powder on some electric properties.

Histone lysine demethylases in mammalian embryonic development

Hongjie Shen,Wenqi Xu,Fei Lan 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Post-translational modifications, such as methylation, acetylation and phosphorylation, of histone proteins play important roles in regulating dynamic chromatin structure. Histone demethylation has become one of the most active research areas of epigenetics in the past decade. To date, with the exception of histone H3 lysine 79 methylation, the demethylases for all major lysine methylation sites have been discovered. These enzymes have been shown to be involved in various biological processes, with embryonic development being an exciting emerging area. This review will primarily discuss the involvement of these demethylases in the regulation of mammalian embryonic development, including their roles in embryonic stem cell pluripotency, primordial germ cell (PGC) formation and maternal-to-zygotic transition.

Robust Stochastic Sampled-data-based Output Consensus of Heterogeneous Multi-agent Systems Subject to Random DoS Attack: A Markovian Jumping System Approach

Hongjie Ni,Zhenhua Xu,Jun Cheng,Dan Zhang 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.7

This paper addresses the robust stochastic sampled-data-based output feedback (SSDBOF) consensuscontroller design for a network of continuous-time heterogeneous multi-agent systems (MASs) in the presence ofdenial-of-service (DoS) attack. Under the mild assumption that the sampling instant is stochastically triggered andsatisfies the Markov property, a homogeneous Markovian jump system (MJS) method is introduced that is capable ofmodeling the stochastic sampled-data-based control system. Furthermore, the randomly occurring Deny-of-Service(DoS) attack problem is also taken into account due to the existence of potential adversary that tries to block thecommunication channels. A novel discrete-time stochastic Markovian system model is first introduced that enablesus to deal with the stochastic sampling and random DoS attack phenomena in a unified framework. Then byadopting the decoupling scheme, some sufficient conditions are proposed such that all the outputs of the followingagents can track the output of the leading agent, and the prescribed H∞ performance level is also guaranteed. Inour work, the SSDBOF consensus controller design method is transformed to a feasibility problem subject to thelinear matrix inequality (LMI) constraints. The theoretical results are finally applied to solve the position trackingproblem of a network of vehicle systems

An Adaptive Compressed Sensing Algorithm of Optical Fiber Pipeline Pre-warning Data

Hongjie Wan,Haojiang Deng,Xiaoming Xie,Qiaoning Yang,Dan Su 보안공학연구지원센터 2013 International Journal of Future Generation Communi Vol.6 No.4

Numerical simulation of the flow in pipes with numerical models

Hongjie Gao,Xinyu Li,Abdolreza Hooshmandi Nezhad,Amir Behshad 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.81 No.4

The objective of this study is to simulate the flow in pipes with various boundary conditions. Free-pressure fluid model, is used in the pipe based on Navier-Stokes equation. The models are solved by using the numerical method. A problem called “stability of pipes” is used in order to compare frequency and critical fluid velocity. When the initial conditions of problem satisfied the instability conditions, the free-pressure model could accurately predict discontinuities in the solution field. Employing nonlinear strains-displacements, stress-strain energy method the governing equations were derived using Hamilton's principal. Differential quadrature method (DQM) is used for obtaining the frequency and critical fluid velocity. The results of this paper are analyzed by hyperbolic numerical method. Results show that the level of numerical diffusion in the solution field and the range of well-posedness are two important criteria for selecting the two-fluid models. The solutions for predicting the flow variables is approximately equal to the two-pressure model 2. Therefore, the predicted pressure changes profile in the twopressure model is more consistent with actual physics. Therefore, in numerical modeling of gas-liquid two-phase flows in the vertical pipe, the present model can be applied.

A MEMS/NEMS sensor for human skin temperature measurement

Hongjie Leng,Yingzi Lin 국제구조공학회 2011 Smart Structures and Systems, An International Jou Vol.8 No.1

Human state in human-machine systems highly affects the overall system performance, and should be detected and monitored. Physiological cues are essential indicators of human state and useful for the purpose of monitoring. The study presented in this paper was focused on developing a bio-inspired sensing system, i.e., Nano-Skin, to non-intrusively measure physiological cues on human-machine contact surfaces to detect human state. The paper is presented in three parts. The first part is to analyze the relationship between human state and physiological cues, and to introduce the conceptual design of Nano-Skin. Generally, heart rate, skin conductance, skin temperature, operating force, blood alcohol concentration, sweat rate, and electromyography are closely related with human state. They can be measured through human-machine contact surfaces using Nano-Skin. The second part is to discuss the technologies for skin temperature measurement. The third part is to introduce the design and manufacture of the Nano-Skin for skin temperature measurement. Experiments were performed to verify the performance of the Nano-Skin in temperature measurement. Overall, the study concludes that Nano-Skin is a promising product for measuring physiological cues on human-machine contact surfaces to detect human state.

Factors Affecting Intention to Use e-Book Sites in China

Hongjie Li(이홍첩),Daeyul Jeong(정대율) 한국인터넷전자상거래학회 2010 인터넷전자상거래연구 Vol.10 No.3

최근 전 세계적으로 디지털 e-Book의 수요가 급속히 확산됨에 따라 기존의 인터넷 서점이나 전문판매 사이트에서도 e-Book을 판매하는 분량이 증가하고 있다. iResearch Consulting Group의 보고서에 따르면 중국은 향후 최대의 e-Book 시장을 형성할 것으로 예측하고 있다. 본 연구에서는 중국인들을 대상으로 e-Book의 구매의도에 영향을 미치는 요인들을 분석하기 위하여 정보기술수용모형을 확장하여 사용하고 있다. 연구모형에서는 e-Book 사이트의 구매의 도에 영향을 미치는 선행독립요인으로 웹사이트의 서비스 능력, 사용자의 자기효능감, 정보품질, 상품다양성으로 하고, 기술수용모형에서 제안하는 사용용이성과 유용성 인지, 태도를 매개 요인으로 하였다. 실증분석 결과, 웹사이트 능력과 자기효능감은 사용용이성에 영향을 미치며, 제품다양성은 유용성 인지에 영향은 미치는 것으로 나타났다. 그러나 정보품질은 유용성 인지에 유의적인 영향을 미친다는 증거를 찾지 못하였다. 매개변수인 사용용이성은 유용성 인지에 긍정적인 영향을 미치고, 이들 두 변수 모두 사용자의 태도에 영향을 미치며, 최종적으로 이용의도에 긍정적인 영향을 미치는 것으로 나타났다. 본 연구를 통하여 기술수용모형에서 제안한 유용성 인지와 태도가 e-Book 사이트의 이용의도에 영향을 미치는 중요한 매개변수임을 밝히고 있다. 따라서 e-Book 사이트에서 유료 서비스를 하기 위해서는 사이트의 서비스 역량을 높여 이용의 편리성을 도모하고, 진열하는 상품의 다양성을 늘여 이용자에게 그 유용성 높여야 한다. 이러한 노력들이 그 사이트에 대한 이용자의 호감을 증가시켜서 이용의도를 높일 수 있고, 또한 다양한 판촉활동을 통하여 그 e-Book 사이트의 판매량을 증가시킬 수 있다.

REGULARITY OF A DEGENERATE PARABOLIC EQUATION APPEARING IN VECER’S UNIFIED PRICING OF ASIAN OPTIONS

Hongjie Dong,김세익 대한수학회 2015 대한수학회보 Vol.52 No.3

Vecer derived a degenerate parabolic equation characterizing the price of Asian options with generally sampled average. It is well understood that there exists a unique probabilistic solution to Vecer’s PDE but it remained unclear whether the probabilistic solution is a classical solution. We prove that the probabilistic solution to Vecer’s PDE is indeed regular.

Performance analysis of PVT systems applicable to apartment housing structures: experiment and simulation

Hongjie Piao,Hakan Caliskan,JAE DONG CHUNG,Jong Hyun Kim,Hiki Hong 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.10

Since Korean apartments are high-rise structures, the only renewable energy that can be applied for ZEB advantage is in fact solar energy. The CO 2 reduction effect of PVT, which can produce heat and electricity at the same time, has already been noted, and is 2.1 times greater than that of PV alone. Like the solar thermal system, the PVT requires a differential temperature controller (mode 1), which can increase the price. In the present work, the new methods, mode 2 and mode 3, that eliminates the costly differential temperature controller was proposed and the experiment was conducted. While electricity is generated from PV, mode 2 operating the circulation pump with this electricity, has some heat loss during weak solar radiation. Mode 3, which supplemented mode 2, showed equivalent performance compared to the existing method, mode 1. The simulation results for these Modes were consistent with the experimental results to within 5 %, and from this, the validity of the existing simulation research results was verified. The annual simulation showed a CO 2 reduction effect of about 158 kg_CO 2 /m 2 year regardless of the method.

Development of Strain Measurement in Superconducting Magnet Through Fiber Bragg Grating

Hongjie Zhang,Fanping Deng,Qiuliang Wang,Luguang Yan,Yingming Dai,Keeman Kim IEEE 2008 IEEE transactions on applied superconductivity Vol.18 No.2

<P>Temperature and strain responses of fiber Bragg grating sensors were measured in cryogenic environment. With temperature from room temperature down to 77 K or 4.2 K, the temperature response was found to be relatively linear above 100 K, and the temperature sensitivity decreases with the decrease of temperature, and to approximately zero for temperature less than 50 K. Technologies were developed to eliminate the multi-peaks in strain experiment, so the strain response was measured at 77 K, and was found to be linear at constant temperatures.</P>