Automated Deployment of a Splash Application to the Distributed System via Splash Build Unit

학위논문(석사) -- 서울대학교대학원 : 공과대학 전기·정보공학부, 2021.8. 홍성수.Splash는 점점 복잡해지는 자율기기(autonomous machine)를 위한 응용 프로그램 개발을 효과적으로 할 수 있는 프로그래밍 프레임워크이다. Splash는 그래픽 사용자 인터페이스를 이용한 프로그래밍 추상화를 제공할 뿐만 아니라 실시간 제어 시스템에 필수적인 실시간 스트림 처리, 센서 퓨전, 모드 변경, 예외 처리 등과 같은 기능들을 제공한다. Splash는 ROS 2에 이미 존재하는 기능의 이점을 이용하기 위해서 ROS 2 기반으로 개발되었다. 따라서, Splash를 사용하여 작성된 응용은 Splash 런타임 라이브러리와 ROS 2 런타임 라이브러리가 설치된 단일 혹은 분산 컴퓨팅 환경에서 구동된다. 하지만 분산 컴퓨팅 환경에서 Splash 응용을 사용하기 위해선 각 머신의 환경에 맞게 응용과 런타임을 빌드 및 설치해야 하고, 이는 소프트웨어 업데이트 및 유지보수를 하는데 시간과 비용이 많이 들도록 한다. 이런 불편함은 분산 컴퓨팅 머신에 확장성(scalability), 가용성(availability), 관리성(manageability)을 고려한 소프트웨어 배포(deployment)의 필요성을 제기한다. 본 논문에서는 Splash 응용 프로그램의 자동화 배포 및 관리를 위한 도커(Docker) 기반 Splash 빌드 유닛을 구현한다. Splash 빌드 유닛을 통해서 개발자는 소프트웨어 빌드 및 배포 프로세스를 자동화하고 프로그램의 병렬성(parallelism) 및 동시성(concurrency)을 최적화할 수 있다. Splash 빌드 유닛을 이용한 소프트웨어 자동화 배포에 대한 유용성을 검증하기 위해서 분산 시스템에서 Splash 빌드 유닛을 이용하여 딥러닝 기반 자율 주행 응용 프로그램의 예제를 진행하였다.Splash is a programming framework that can effectively support the application development of increasingly complex autonomous machines. Splash not only offers user-friendly programming abstraction like a graphic user interface, but also provides essential programming semantics for a real-time control system such as real-time stream processing, sensor fusion, mode change, exception handling, etc. Splash was developed based on ROS 2 to take advantages of using already existing features and packages. Splash applications are eligible to run on a single or distributed computing systems where Splash runtime library, ROS 2 runtime library and any other software that are necessary for the Splash applications are installed. Therefore, in order to run Splash application on a distributed computing system, it is required to build and install the applications, additional external libraries and corresponding runtime according to the environment of each machine. This particular process comes with cost and time issue of software update and maintenance. This inconvenience and burden raise the need for automated software deployment considering scalability, availability, and manageability in distributed computing systems. This thesis will introduce a Docker-based Splash build unit for automated deployment and management of Splash applications. Splash build unit allows developers to automate the software build and deployment process to distributed computing machines by using Docker containerization. It also allows developers to focus on optimizing parallelism and concurrency of programs. In order to demonstrate the effectiveness and utility of software deployment using Splash build unit, the case study of a LFA(Lane Following Assist) application with DNN-based lane detection and DNN-model training program was conducted using Splash build unit in a distributed system.제 1 장 서 론 1 제 2 장 배경 지식 3 제 1 절 ROS 2 3 제 2 절 Splash 7 제 3 장 도커 기반 빌드 유닛 15 제 1 절 빌드 유닛 15 제 2 절 도커 기반 빌드 유닛 및 구현 17 제 3 절 빌드 유닛 배포 19 제 4 장 Case Study 21 제 1 절 예제 환경 21 제 2 절 예제 구성 22 제 3 절 예제 결과 및 평가 24 제 5 장 결 론 26 참고문헌 27 Abstract 29석

PROGRAPE-1: A Programmable, Multi-Purpose Computer for Many-Body Simulations

We have developed PROGRAPE-1 (PROgrammable GRAPE-1), a programmable multi-purpose computer for many-body simulations. The main difference between PROGRAPE-1 and "traditional" GRAPE systems is that the former uses FPGA (Field Programmable Gate Array) chips as the processing elements, while the latter rely on the hardwired pipeline processor specialized to gravitational interactions. Since the logic implemented in FPGA chips can be reconfigured, we can use PROGRAPE-1 to calculate not only gravitational interactions but also other forms of interactions such as van der Waals force, hydrodynamical interactions in SPH calculation and so on. PROGRAPE-1 comprises two Altera EPF10K100 FPGA chips, each of which contains nominally 100,000 gates. To evaluate the programmability and performance of PROGRAPE-1, we implemented a pipeline for gravitational interaction similar to that of GRAPE-3. One pipeline fitted into a single FPGA chip, which operated at 16 MHz clock. Thus, for gravitational interaction, PROGRAPE-1 provided the speed of 0.96 Gflops-equivalent. PROGRAPE will prove to be useful for wide-range of particle-based simulations in which the calculation cost of interactions other than gravity is high, such as the evaluation of SPH interactions.Comment: 20 pages with 9 figures; submitted to PAS

Solar Splash Senior Design Project

Indiana University Purdue University IndianapolisThe Solar Splash senior project is the first attempt at creating an entirely solar propelled watercraft. The initial project intent was to design and create a supplement meets the specifications and compete in the competition. With this in mind, a budget approach was taken in order to be able to fund the task at hand. As the project progressed toward the end of the low-level design phase it was evident that the competition would not occur. At the midpoint of the project, the goals and objectives had changed entirely. The new focus was targeted at proving the operation of the systems involved in the watercraft. Having been faced with a new series of objectives and an entirely new scope, the project began to appear doable. The primary focus of the project at this point entirely relied on simulation data and data analysis. The idea was not reinventing the wheel but rather verifying that the wheel rolled. Using the designed propulsion, solar and sensors systems, with the help of a combination of software programs, the idea of a budget solution can be seen. The software used tell the story of the boat that would have been created had the project continued down the original proposed path. As systems were tested and analyzed, they were also adjusted and improved upon. The analysis process consumed a lot of time but acted as a highlighter for all the flaws that the system suffered from. This document introduces the design concepts and schematics of the Solar Splash senior design project. Within are detailed drawings and diagrams for the electrical systems devised for the construction operation of the watercraft. This report is a means of displaying the layout of the final product and how all systems tie together. The report will contain detailed information on not only hardware aspects but also software and how those will bridge together. The report is meant to be in layman’s terms and should be easily interpreted at all levels. The bulk of the information found in the report will be found in the testing sections where analysis of a theoretical boat is done. The motor design, solar design, and fluid dynamic analysis of the boat hull and propeller can be found in their respective section. The innerworkings, testing processes and thoughts behind each decision can also be found in these sections. The document begins with a table of contents identifying each main and subcategory of information. The next page is the document identification, revision history, and lesser known definitions. Following that is the introduction and scope. Specification requirements for the ‘general requirements’, ‘electrical requirements’ and ‘mechanical requirements’ are found on the following page. A system flowchart can be found in the high-level Design along with the design decision matrices for each system. The design portion then begins starting with the System-wide design changes and decisions. The hardware and software designs and schematics follow and cover the proposed schematics and drawings for the system. Cost breakdowns for each individual system are also found in the low-level section. Testing methodologies, results and an explanation of the testing software can be found after the low-level design. A summation of all these testing results is found near the tail of the document. Conclusions, recommendations, and appendixes can be found as the last three sections, respectively.Electrical Engineering Technolog

Potential use of BEST® sediment trap in splash-saltation transport process by simultaneous wind and rain tests

The research on wind-driven rain (WDR) transport process of the splash-saltation has increased over the last twenty years as wind tunnel experimental studies provide new insights into the mechanisms of simultaneous wind and rain (WDR) transport. The present study was conducted to investigate the efficiency of the BEST® sediment traps in catching the sand particles transported through the splash-saltation process under WDR conditions. Experiments were conducted in a wind tunnel rainfall simulator facility with water sprayed through sprinkler nozzles and free-flowing wind at different velocities to simulate the WDR conditions. Not only for vertical sediment distribution, but a series of experimental tests for horizontal distribution of sediments was also performed using BEST® collectors to obtain the actual total sediment mass flow by the splash-saltation in the center of the wind tunnel test section. Total mass transport (kg m-2) were estimated by analytically integrating the exponential functional relationship using the measured sediment amounts at the set trap heights for every run. Results revealed the integrated efficiency of the BEST® traps at 6, 9, 12 and 15 m s-1 wind velocities under 55.8, 50.5, 55.0 and 50.5 mm h-1 rain intensities were, respectively, 83, 106, 105, and 102%. Results as well showed that the efficiencies of BEST® did not change much as compared with those under rainless wind condition

Power aware early design stage hardware software co-optimization

Co-optimizing hardware and software can lead to substantial performance and energy benefits, and is becoming an increasingly important design paradigm. In scientific computing, power constraints increasingly necessitate the return to specialized chips such as Intel’s MIC or IBM’s Blue-Gene architectures. To enable hardware/software co-design in early stages of the design cycle, we propose a simulation infrastructure methodology by combining high-abstraction performance simulation using Sniper with power modeling using McPAT and custom DRAM power models. Sniper/McPAT is fast — simulation speed is around 2 MIPS on an 8-core host machine — because it uses analytical modeling to abstract away core performance during multi-core simulation. We demonstrate Sniper/McPAT’s accuracy through validation against real hardware; we report average performance and power prediction errors of 22.1% and 8.3%, respectively, for a set of SPEComp benchmarks

A Configurable Transport Layer for CAF

The message-driven nature of actors lays a foundation for developing scalable and distributed software. While the actor itself has been thoroughly modeled, the message passing layer lacks a common definition. Properties and guarantees of message exchange often shift with implementations and contexts. This adds complexity to the development process, limits portability, and removes transparency from distributed actor systems. In this work, we examine actor communication, focusing on the implementation and runtime costs of reliable and ordered delivery. Both guarantees are often based on TCP for remote messaging, which mixes network transport with the semantics of messaging. However, the choice of transport may follow different constraints and is often governed by deployment. As a first step towards re-architecting actor-to-actor communication, we decouple the messaging guarantees from the transport protocol. We validate our approach by redesigning the network stack of the C++ Actor Framework (CAF) so that it allows to combine an arbitrary transport protocol with additional functions for remote messaging. An evaluation quantifies the cost of composability and the impact of individual layers on the entire stack

Reconfigurable interconnects in DSM systems: a focus on context switch behavior

Recent advances in the development of reconfigurable optical interconnect technologies allow for the fabrication of low cost and run-time adaptable interconnects in large distributed shared-memory (DSM) multiprocessor machines. This can allow the use of adaptable interconnection networks that alleviate the huge bottleneck present due to the gap between the processing speed and the memory access time over the network. In this paper we have studied the scheduling of tasks by the kernel of the operating system (OS) and its influence on communication between the processing nodes of the system, focusing on the traffic generated just after a context switch. We aim to use these results as a basis to propose a potential reconfiguration of the network that could provide a significant speedup