Earticle

The working space is one of the important indexes to measure the working capability of parallel mechanism. In this paper, the working space of a new type of 3-PRS parallel mechanism is studied. In the beginning, a novel 3-PRS parallel mechanism is proposed with the kinematics analyzed, and then the working space and volume are obtained by search algorithm, and the working space is drawn using MATLAB. Finally, the influence of the structural parameters on the working space is discussed, which provide theoretical basis for parameter optimization.

A large-scale analysis to evaluate complex material and structural behaviors is one of interesting topic in diverse engineering and scientific fields. Also, the utilization of massively parallel processors has been a recent trend of high performance computing. The objective of this paper is to introduce a parallel process system which consists of general purpose finite element analysis solver as well as parallelized PC cluster. The later was constructed using eight processing elements and the former was developed adopting both hierarchical domain decomposition method and balancing domain decomposition method. Then, to verify the efficiency of the established system, it was applied for structural analysis of steam generator in nuclear power plant. Since the prototypal evaluation results agreed well to the corresponding reference solutions it is believed that, after reinforcement of PC cluster by increasing number of processing elements, the promising parallel process system can be utilized as a useful tool for advanced structural integrity evaluation.

The computational environment in which engineers perform their designs has been rapidly evolved from coarse serial machines to massively parallel machines. Although the recent development of high-performance computers are available for a number of years, only limited successful applications of the new computational environments in computational structural engineering field has been reported due to its limited availability and large cost associated with high-performance computing. As a new computational model for high-performance engineering computing without cost and availability problems, parallel structural analysis models for large scale structures on a network of personal computers (PCs) are presented in this paper. In structural analysis solving routine for the linear system of equations is the most time consuming part. Thus, the focus is on the development of efficient preconditioned conjugate gradient (PCG) solvers on the proposed computational model. Two parallel PCG solvers, PPCG-I and PPCG-II, are developed and applied to analysis of large scale space truss structures.

본 논문은 최근에 널리 사용되는 다중코어 컴퓨팅 환경에서 병렬 다중프론트 해법의 스케쥴링 및 부하조절 기법에 대해 논의한다. 통상적으로 구조해석 문제들은 불규칙한 격자계와 혼재된 물성 때문에 병렬화 알고리즘 구현 시 병목현상을 일으키고 불필요한 유휴시간을 초래한다. 따라서 이를 극복하며 효율성을 향상시키기 위해 다중쓰레드 기반 환경에 걸맞는 작업 스케쥴링 및 부하 분산 기법의 적용이 필수적이다. 본 논문에서 제시된 정적, 동적 스케줄링 기법과 정적 전 임무 분산, 최소최대 임무 결합 등의 부하 분산 기법들에 대한 이론적, 실제 결과를 제시함으로서 그 유용성을 논의하고자 한다.

In this paper, task scheduling and load balancing methods of multifrontal solution methods of finite element structural analysis in a modern multicore machine are introduced. Many structural analysis problems have generally irregular grid and many kinds of properties and materials. These irregularities and heterogeneities lead to bottleneck of parallelization and cause idle time to analysis. Therefore, task scheduling and load balancing are desired to reduce inefficiency. Several kinds of multithreaded parallelization methods are presented and comparison between static and dynamic task scheduling are shown. To reduce the idle time caused by irregular partitioned subdomains, computational load balancing methods, Balancing all tasks and minmax task pairing balancing, are invented. Theoretical and actual elapsed time are shown and the reason of their performance gap are discussed.

패러럴 슬라이드 게이트밸브는 복합발전플랜트 배열회수보일러와 증기터빈 사이에 위치하여 증기유동의 흐름을 제어하는 밸브로서 운전기간 동안 기동, 부하변동 및 정지 등의 운전이 반복적으로 이루어진다. 따라서, 각 기동운전 중에 밸브 두께 방향의 온도 차이로 인하여 발생하는 큰 압축 열응력으로 인한 피로손상 및 구조건전성에 대한 평가가 필요하다. 본 논문에서는 배열회수보일러의 주중기 밸브로 설치되는 16인치 패러럴 슬라이드 게이트밸브의 피로수명 평가를 위한 열구조해석 및 ASME B&PVC VIII-2에서 제시된 탄성응력해석 및 등가응력에 기반한 피로수명 평가를 수행하였다.

A parallel slide gate valve (PSGV) is located between the heat recovery steam generator (HRSG) and the steam turbine in a combined cycle power plant (CCPP). It is used to control the flow of steam and runs with repetitive operations such as startups, load changes, and shutdowns during its operation period. Therefore, it is necessary to evaluate the fatigue damage and the structural integrity under a large compressive thermal stress due to the temperature difference through the valve wall thickness during the startup operations. In this paper, the thermal-structural analysis and the fatigue life evaluation of a 16-inch PSGV, which is installed on the HP steam line, is performed according to the fatigue life assessment method described in the ASME B&PVC VIII-2; the method uses the equivalent stress from the elastic stress analysis.

본 논문은 수사권 조정 이후 사법경찰관의 불송치 결정에 대한 권리구제 제도를, 개별 절차 간의 선택 문제로 파악해 온 종전의 논의 틀에서 벗어나 구조적으로 재검토한다. 종래 논의는 수사심의신청과 이의신청을 서로 대체적이거나 병존하는 제도로 이해하거나, 검사의 재수사요청 제도를 사경의 불송치 권한과의 긴장 관계 또는 기록 검토 방식의 실효성 부족 등을 이유로 비판적으로 평가해 왔다. 이에 대하여 본 논문은 불송치 결정에 대한 권리구제 절차 전반을 하나의 체계로 파악하고, 수사심의신청과 이의신청이 검사의 재수사요청 판단을 매개로 기능적으로 연계되는 병행적 통제 구조를 형성하고 있음을 논증한다. 이러한 관점에 따르면, 수사심의신청과 이의신청은 서로 독립적으로 병존하는 제도가 아니라, 사경의 불송치 결정의 적법성과 적정성을 다층적으로 점검하기 위한 통제 장치로서 상호 연계되어 작동하는 제도적 구조로 이해될 수 있다. 특히 재수사요청 제도는 고립된 통제 수단으로 전제될 경우 그 실효성에 대한 비판이 제기될 수 있으나, 권리구제 절차의 전체적 맥락에서 파악할 경우 불송치 결정에 대한 판단을 매개적으로 조정·연결하는 제도적 장치로 재평가될 여지가 있다. 본 논문은 이러한 구조적 이해를 바탕으로 현행 법령 및 검찰 개편 논의에 포함된 불송치 결정 통제 규정들을 검토하고, 그 헌법적·제도적 한계를 분석하였다. 특히 수사심의위원회 의결의 법적 성격과 관련하여, 법률유보의 원칙과 본질성 이론에 비추어 볼 때 불송치 결정에 실질적인 영향을 미치는 사항은 법률에 의한 규율이 요구된다는 점을 지적하였다. 나아가 형사피해자인 고소인의 헌법상 재판절차진술권과 검사의 법률상 수사권·기소권이 병존하는 구조 하에서, 불송치 결정에 대한 통제 장치를 어떻게 설계할 것인지가 중요한 헌법적 쟁점임을 부각시킨다. 이와 같은 논의는 불송치 결정 통제 제도를 제도 간 우열이나 선택의 문제로 환원하는 접근을 넘어서, 수사권이 분산된 형사사법 구조 하에서 권한 배분과 권리 보장을 조화시키는 통제 메커니즘을 어떻게 설계할 것인가라는 구조적·제도설계적 관점의 필요성을 제시한다는 점에서 의의를 가진다.

This article undertakes a structural reexamination of the remedies available against non-prosecution decisions rendered by judicial police officers following the reform of investigative authority in Korea. Departing from prior approaches that have framed these remedies primarily as a matter of choosing among discrete procedural options, this article reconceptualizes the overall system of review mechanisms applicable to non-prosecution decisions. Conventional analyses have tended to regard applications for investigative review and objections as either alternative or merely coexisting procedures, or have critically assessed the prosecutor’s request for reinvestigation on the grounds of its tension with the police’s authority to decide non-prosecution or the alleged ineffectiveness of record-based review. In contrast, this article argues that the remedies against non-prosecution decisions should be understood as forming an integrated system, in which applications for investigative review and objections are functionally linked through the prosecutor’s decision on whether to request reinvestigation, thereby constituting a parallel and interrelated control structure. From this perspective, investigative review applications and objections are not independent or duplicative mechanisms, but rather interconnected institutional devices designed to conduct multilayered scrutiny of the legality and appropriateness of non-prosecution decisions made by the police. In particular, while the reinvestigation request mechanism may appear ineffective when viewed in isolation, it can be re-evaluated as an institutional device that mediates and coordinates judgments on non-prosecution decisions when situated within the broader context of the remedial framework. Based on this structural understanding, the article examines relevant provisions in the current statutory framework and in recent prosecutorial reform proposals concerning the control of non-prosecution decisions, and analyzes their constitutional and institutional limitations. Special attention is paid to the legal nature of resolutions adopted by investigative review committees. In light of the principle of statutory reservation and the theory of essential matters, the article contends that matters exerting a substantive influence on non-prosecution decisions must be regulated by statute. Furthermore, it highlights the constitutional significance of designing appropriate control mechanisms for non-prosecution decisions within a framework in which the crime victim’s constitutional right to be heard in criminal proceedings coexists with the prosecutor’s statutory authority to investigate and prosecute. Ultimately, this article demonstrates the necessity of moving beyond an approach that reduces the control of non-prosecution decisions to questions of institutional hierarchy or procedural choice. Instead, it underscores the importance of a structural and institutional design perspective that seeks to harmonize the allocation of investigative authority with the protection of individual rights in a criminal justice system characterized by the dispersion of investigative powers.