Effect of bogie fairings on the snow reduction of a high-speed train bogie under crosswinds using a discrete phase method

Guangjun Gao,Yani Zhang,Jie Zhang,Fei Xie,Yan Zhang,Jiabin Wang 한국풍공학회 2018 Wind and Structures, An International Journal (WAS Vol.27 No.4

This paper investigated the wind-snow flow around the bogie region of a high-speed train under crosswinds using a coupled numerical method of the unsteady Realizable k-ε turbulence model and discrete phase model (DPM). The flow features around the bogie region were discussed and the influence of bogie fairing height on the snow accumulation on the bogie was also analyzed. Here the high-speed train was running at a speed of 200 km/h in a natural environment with the crosswind speed of 15 m/s. The mesh resolution and methodology for CFD analysis were validated against wind tunnel experiments. The results show that large negative pressure occurs locally on the bottom of wheels, electric motors, gear covers, while the positive pressure occurs locally on those windward surfaces. The airflow travels through the complex bogie and flows towards the rear bogie plate, causing a backflow in the upper space of the bogie region. The snow particles mainly accumulate on the wheels, electric motors, windward sides of gear covers, side fairings and back plate of the bogie. Longer side fairings increase the snow accumulation on the bogie, especially on the back plate, side fairings and brake clamps. However, the fairing height shows little impact on snow accumulation on the upper region of the bogie. Compared to short side fairings, a full length side fairing model contributes to more than two times of snow accumulation on the brake clamps, and more than 20% on the whole bogie.

Optimization of the anti-snow performance of a high-speed train based on passive flow control

Guangjun Gao,Zhen Tian,Jiabin Wang,Yan Zhang,Xinchao Su,Jie Zhang 한국풍공학회 2020 Wind and Structures, An International Journal (WAS Vol.30 No.4

In this paper, the improvement of the anti-snow performance of a high-speed train (HST) is studied using the unsteady Reynolds-Averaged Navier-Stokes simulations (URANS) coupled with the Discrete Phase Model (DPM). The influences of the proposed flow control scheme on the velocity distribution of the airflow and snow particles, snow concentration level and accumulated mass in the bogie cavities are analyzed. The results show that the front anti-snow structures can effectively deflect downward the airflow and snow particles at the entrance of the cavities and alleviate the strong impact on the bogie bottom, thereby decrease the local accumulated snow. The rotational rear plates with the deflecting angle of 45° are found to present well deflecting effect on the particles’ trajectories and force more snow to flow out of the cavities, and thus significantly reduce the accretion distribution on the bogie top. Furthermore, running speeds of HST are shown to have a great effect on the snow-resistance capability of the flow control scheme. The proposed flow control scheme achieves more snow reduction for HST at higher train’s running speed in the cold regions.

Study on the Construction of a Mechanism to Coordinate Interests in the Exercise of the Right to Transfer Personal Information

Guangjun Zhang(?光君),Kexin Zheng(?可欣) 동아대학교 법학연구소 2022 東亞法學 Vol.- No.97

중국의 개인정보보호법은 처음으로 개인정보양도권을 확립하고 국가인터넷정보통신부가 관련 시행세칙을 제정하도록 허가 하고 있다. 개인정보 이전권은 유럽연합 일반 데이터 보호 규정에서 정한 데이터 이전 권리에 대한 제안이지만 개인정보 이전 권리를 행사하는 과정에서 제3자 플랫폼과 원 플랫폼 간 이해 충돌이 발생할 수 있다. 이익 조정 메커니즘의 구축은 관련 시행 규칙을 제정하는 핵심 과제로 개인정보 이전권 행사의 장벽을 줄이는 데 도움이 되어 개인정보를 잘 활용할 수 있고 동시에 잘 보호할 수 있다. “오늘의 헤드라인” 사례는 개인정보이전에 따른 이해충돌의 복잡성을 잘 보여주고 있으며, 조정메커니즘을 시급히 구축해야 할 필요성이 있음을 잘 보여주고 있다. 개인정보 이전권의 체계적인 권리구조를 구축함으로써 개인정보 이전권이 데이터 휴대권과 다르다는 특수성을 보여준다. 충돌하는 두 플랫폼의 각각의 이익을 분석해 볼 때, 어느 일방에게만 유리하게 보호하는 것은 바람직하지 않다. 각계각층의 다양한 이해관계를 조율할 수 있는 장치가 마련돼야 한다. 그 내용으로 다음과 같은 방안이 제시될 수 있다. 첫째, 비용분담 메커니즘을 구축할 필요가 있다. 제3자 플랫폼은 대가 지급을 통해 기존 플랫폼과 개인정보 이전 비용을 공동 부담한다.원래 플랫폼은 독립적으로 인증 비용을 부담하며 다양한 유형의 개인정보에 따라 다양한 인증방법과 프로세스를 채택한다. 둘째, 의무분배 메커니즘을 수립해야 한다. 기존 플랫폼은 제3자 플랫폼의 컴플라이언스 의무 이행 능력을 심사해 이행 능력이 부족한 제3자 플랫폼에 도움을 줘야 하지만, 일정 기간 후 탈퇴할 수 있는 메커니즘을 설정할 필요가 있다. 전송의무에서 정보이전을 이전단계와 환원단계로 구분하여 의무의 분배. 보안 의무 측면에서 기존 플랫폼이 주요 책임을 지고 제3자 플랫폼이 보조 책임을 지며 보험 가입을 통해 위험을 균등하게 부담한다. China’s Personal Information Protection Law establishes the right to transfer personal information for the first time and authorizes the state Internet information department to formulate relevant implementation rules. Although the right to transfer personal information is a limitation of the right to carry data as stipulated in the EU General Data Protection Regulation(GDPR), the process of exercising the right to transfer personal information still leads to conflict of interests between the third-party platform and the original platform. Constructing a mechanism for coordination of interests is a key task in formulating relevant implementation rules, which is conducive to reducing resistance to the exercise of the right to transfer personal information and realizing the dual purpose of “strong use and protection” of personal information. The introduction of the “Today’s headlines case” highlights the complexity of the conflict of interest in the transfer of personal information and illustrates the urgency of constructing a mechanism for coordination of interests. Then, we systematically construct the right structure of the right to transfer personal information and reveal its special features that distinguish it from the right to carry data. The analysis of the respective interests of the two platforms shows that it is not desirable to adopt a single value orientation for protection, but rather to construct a coordination mechanism for the coexistence of multiple interests. Further, in the process of exercising the right to transfer personal information, it is necessary to balance the interests of the original platform and the third-party platform in terms of cost-sharing mechanism and obligation-sharing mechanism. First, about the cost-sharing mechanism. The third-party platform should share the cost of transferring personal information with the original platform by paying the consideration; the cost of identity verification should be borne by the original platform independently, and the way and process of identity verification should be distinguished according to the type of personal information. Secondly, about the obligation sharing mechanism. The original platform shall review the third-party platform’s ability to fulfill compliance obligations and provide assistance to those with insufficient ability to fulfill obligations, but set up an exit mechanism within a certain period of time; among the transmission obligations, distinguish between transfer and restoration for obligation sharing; among the security obligations, the original platform shall bear the main responsibility while the third-party platform shall bear the auxiliary responsibility, and share the risks among them equally by purchasing insurance.

Homomorphic Subspace MAC Scheme for Secure Network Coding

Guangjun Liu,Xiao Wang 한국전자통신연구원 2013 ETRI Journal Vol.35 No.1

Existing symmetric cryptography-based solutions against pollution attacks for network coding systems suffer various drawbacks, such as highly complicated key distribution and vulnerable security against collusion. This letter presents a novel homomorphic subspace message authentication code (MAC) scheme that can thwart pollution attacks in an efficient way. The basic idea is to exploit the combination of the symmetric cryptography and linear subspace properties of network coding. The proposed scheme can tolerate the compromise of up to r–1 intermediate nodes when r source keys are used. Compared to previous MAC solutions, less secret keys are needed for the source and only one secret key is distributed to each intermediate node.

Design and Simulation Study of A C-band PHEMT MMIC Power Amplifier for Wireless Local Area Network Application

Guangjun Wen,Bonghyuk Park,Haewon Jung,Hyeong Ho Lee 한국통신학회 2000 한국통신학회 학술대회논문집 Vol.2000 No.11

Inspection and Improvement of Arrest Hearing System under the Background of “Integration of Arrest and Prosecution”

Guangjun Zhang(張光君),Xue Tang(唐雪) 동아대학교 법학연구소 2021 東亞法學 Vol.- No.93

중국은 2012년 “형사소송법”을 개정하면서 검찰의 영장심사 방식을 소송화 했지만 “포소합일” 개혁 이후 영장심사권의 사법성이 약화되는 추세다. 체포 청문회는 현재 검찰기관이 직면한 곤경에 따라 자주적으로 선택하는 최우선의 해결방안으로 행정심사비준식의 체포심사절차를 “공개화”된 소송화 절차로 유도함으로써 ‘체포합일’개혁이 초래하는 불리한 결과를 줄일 수 있다. 그러나 현재 중국 각지의 검찰기관이 실시하는 체포청문 제도는 적용 범위가 좁고, 기준이 통일되지 않으며, 프로그래밍이 과학적이지 않아, 절실히 모색하여 보완할 수 있는 방법이 필요하다. 본문은 체포심사 절차의 고유한 행정화 결함으로부터 출발하여 “포소합일”의 사법적 배경과 결합하여 체포심사 과정에 존재하는 문제점과 원인에 대하여 분석한다. 다음으로, “포소합일”의 배경하에 실시된 체포청문제도의 이론적 정당성을 분석하고 체포청문제도의 시범과정에서의 경험과 교훈에 대하여 총화를 진행하였다. 마지막으로 적용범위, 청문형식, 청문결정권 등 각도에서 “포소합일”의 배경에 따른 체포청문제도의 보완조치를 모색하여 검찰기관의 체포심사업무의 행정심사비준 색채를 희석시키고 체포심사절차의 정당성을 강화한다. 체포소추합일의 맥락에서 체포 청문 제도가 갖는 책임의 불명확성, 내부감시의 약화 등에 대한 문제점 본문은 분류식 체포비준양식을 구축하고, 체포 청문제도의 안건범위를 적당히 확대하여 적용하며, “사회자가 중앙에 위치하여 심리를 청취하고, 조사하며, 쌍방이 평등하게 대항하고, 청문회원이 평등하게 참여하는” 공개심리구조를 구축할 것을 제기한다. 입증책임을 수사기관에 부여하고 동시에 범죄혐의자 및 그 변호인에게 반박과 대질의 권리를 부여하며, 청문회원의 다수 의견을 결정의 근거로 하여 중국 형사법치 발전단계에 적응하는 체포청문제도를 구축함으로써 “재판을 중심으로”의 소송체제 개혁을 추진한다. Although China revised the Criminal Procedure Law in 2012, the procuratorial organs" way of examining and approving arrest was reformed into litigation, after the reform of “integration of arrest and prosecution”, the judicature of the right of examining and approving arrest tended to be weakened. Arrest hearing is the best solution that procuratorial organs choose independently according to the difficulties they face. Guiding the administrative examination and approval procedure to the “open” litigation procedure can reduce the adverse consequences brought by the reform of “integration of arrest and prosecution”. However, at present, the arrest hearing system carried out by procuratorial organs in various parts of China is narrow in scope of application, inconsistent in standards and unscientific in program design, so it is urgent to explore ways to improve it. This article starts from the inherent administrative defects of the procedure of examination and arrest, combined with the judicial background of the “integration of arrest and prosecution”, analyzes the problems and reasons existing in the process of examination and arrest; Secondly, it analyzes the theoretical legitimacy of carrying out the arrest hearing system under the background of he “integration of arrest and prosecution”, and summarizes the experience and lessons in the pilot process of the arrest hearing system. Finally, from the scope of application, hearing form, hearing decision-making power and other angles, explore the improvement measures of arrest hearing system under the background of “integration of arrest and prosecution”, so as to weaken the administrative examination and approval characteristics of procuratorial organs" arrest review work and strengthen the legitimacy of arrest review procedure. In view of the problems existing in the arrest hearing system under the background of “integration of arrest and prosecution”, such as unclear power and responsibilities and weakened internal supervision. This paper proposes to establish a diversion mode of arrest, moderately expand the scope of cases applying the arrest hearing system, and establish a public hearing structure of “the host hears in the middle, the investigation and the defense are equally confronted, and the hearing officers participate equally”. The burden of proof is given to the investigative agency, and the suspect and his defense lawyer are given the right to refute and cross-examine. Decisions are made on the basis of the majority opinion of the hearing officer, with a view to building an arrest hearing system that adapts to the development stage of China"s criminal rule of law, thereby helping promote the reform of the “trial-centered” litigation system.

On the convergence to the multiple subfractional Wiener–Itô integral

Guangjun Shen,Litan Yan,Chao Chen 한국통계학회 2012 Journal of the Korean Statistical Society Vol.41 No.4

In this paper, we construct a family of continuous stochastic processes that converges in law to the multiple Wiener–Itô integrals with respect to the subfractional Brownian motion withH > 12 for the integrand f in a rather general class of functions.Wemainly use Donsker and Stroock approximations and the techniques of the multiple Wiener–Itô integral with respect to the Wiener process.

Remarks on an integral functional driven by sub-fractional Brownian motion

Guangjun Shen,Litan Yan 한국통계학회 2011 Journal of the Korean Statistical Society Vol.40 No.3

This paper studies the functionals A1(t, x) = ∫ ^t _01_[0,∞)(x − S^H _s )ds,A_2(t, x) = ∫^ t _01_[0,∞)(x − S^H _s )s^(2H−1)ds,where (S^H _t )0≤t≤T is a one-dimension sub-fractional Brownian motion with index H ∈ (0, 1). It shows that there exists a constant pH ∈ (1, 2) such that p-variation of the process A_j(t, S^H_t ) − ^t _0 L_j(s, ^S_H s )dS^H _s (j = 1, 2) is equal to 0 if p > pH, where L_j, j = 1, 2, are the local time and weighted local time of S^H, respectively. This extends the classical results for Brownian motion.

A Preliminary Study on the Four-stage Strategy of Judicial Application of Blockchain in China

Guangjun Zhang(張光君),Xinyun Hu(胡馨?) 동아대학교 법학연구소 2020 東亞法學 Vol.- No.89

블록체인의 본질은 분산 컴퓨팅기술에 기반한 모든 노드 공동장부의 방식으로 개체간에는 더이상 상호 신임할 필요가 없다는 효과를 구현한 것이다. 블록체인은 변조불가, 소급가능, 시간표 등 기술특성을 갖고 있어 사법분야에서의 응용전망이 아주 넓으며, 이미 중국 사법개혁의 핫한 이슈가 되어 있다. 그러나 현재 블록체인 사법응용의 발전단계에 대한 인식, 발전전략이 명확하지 않기에 실무에서 블록체인 응용에 대한 총체적 방향감이 부족하다. 때문에 중국 블록체인 사법응용 발전전략을 모색하는 것이 절실하다. 블록체인의 중국에서의 사법응용과 발전은 순 이론적인 허황한 환상이 아니라 튼튼한 기술적 기초가 있다. 현재 중국 블록체인의 사법응용 발전전략단계와 전략중점이 명확하지 않은 문제점을 해결하고저 본고는 블록체인 고유의 기술특점으로부터 출발하여 블록체인의 발전추세, 기존의 실천 및 사법응용의 최종적목표와 결부하여 중국 블록체인 사법응용의 4단계 전략을 제시하였다. 본고는 또 블록체인을 이용한 증거보존과 수집, 데이터처리혁신, 장비, 프로그램의 연계 및 법코드화 4단계로 나누었다. 본고에서는 블록체인 사법응용 4단계 발전전략의 특점에 대해 각 단계 전략실시의 중점을 제시하였는데 이는 학술계가 블록체인 사법응용발전전략에 대한 연구에 대해 관심을 갖도록 하는데 뜻을 두고 있다. 사법실무면에서 이 글은 블록체인의 사법응용의 최종방향과 단계적 목표를 제시하였다. 사법기관은 블록체인기술을 활용하여 분쟁을 해결하는 과정에서 뚜렷한 목표를 가지게 되고 이로써 사법효률을 현저히 제고하고 사법공정성을 촉진하는 동시에 사회관리혁신을 추진하고 사회관리효률을 향상하는데 새로운 길을 개척할 수 있을 것이다. 그리고 이 글은 중국 및 다른 나라의 블록체인으로 사법개혁을 하는데 있어 이론적 가치가 있으면 한다. Blockchain is in essence a distributed account book technology, which makes mutual trust among individuals unnecessary via the joint bookkeeping of all participating nodes. Since the Blockchain technology is anti-tampering, traceable, and has the timestamp, there is a promising prospect for its application to the judicial field. This has turned Blockchain into a hotspot issue of China’s judicial reform. However, due to an ambiguous understanding of the development stage and strategies of the judicial application of Blockchain, there lacks an overall direction for such application. This necessitates the exploration of the development strategies for the judicial application of Blockchain in China. The application and development of Blockchain in China’s judicial practice is supported by solid technical foundation, rather than pure theoretical fantasy. In order to solve the problems of unclear strategic stage and unclear strategic focus in the development of China’s Blockchain judicial application, this paper starts with the technical characteristics of Blockchain, combines with the development trend of Blockchain, existing practice and the ultimate goal of judicial application, to propose the four-stage development strategy for the judicial application of Blockchain in China. The four development stages include the Blockchain evidence collection and storage, data governance innovation, device and program interconnection, and legal coding. Concerning the characteristics of the four-stage development strategy for judicial application of Blockchain in China, this paper proposes the implementation focuses for different strategic stages at an attempt to draw the academic circles’ attention to this research issue. For judicial practice, this paper points out the ultimate direction and stage goal for the judicial application of China’s blockchain to a certain extent, so that the judicial organs can have a definite target in the process of applying Blockchain to solve disputes, so as to effectively improve judicial efficiency and promote judicial justice, and at the same time, it also opens up a new way to promote social governance innovation and enhance social governance efficiency. This study may have certain theoretical reference value for China and other countries to promote judicial reform with the help of Blockchain.

Neutral stochastic partial differential equations with delay driven by Rosenblatt process in a Hilbert space

Guangjun Shen,Yong Ren 한국통계학회 2015 Journal of the Korean Statistical Society Vol.44 No.1

In this paper, we prove an existence and uniqueness result of the mild solution for a neutralstochastic partial differential equations with finite delay driven by Rosenblatt process in areal separable Hilbert space. An example is provided to illustrate the effectiveness of theproposed result.