Formal mechanization of device interactions with a process algebra

The principle emphasis is to develop a methodology to formally verify correct synchronization communication of devices in a composed hardware system. Previous system integration efforts have focused on vertical integration of one layer on top of another. This task examines 'horizontal' integration of peer devices. To formally reason about communication, we mechanize a process algebra in the Higher Order Logic (HOL) theorem proving system. Using this formalization we show how four types of device interactions can be represented and verified to behave as specified. The report also describes the specification of a system consisting of an AVM-1 microprocessor and a memory management unit which were verified in previous work. A proof of correct communication is presented, and the extensions to the system specification to add a direct memory device are discussed

Towards composition of verified hardware devices

Computers are being used where no affordable level of testing is adequate. Safety and life critical systems must find a replacement for exhaustive testing to guarantee their correctness. Through a mathematical proof, hardware verification research has focused on device verification and has largely ignored system composition verification. To address these deficiencies, we examine how the current hardware verification methodology can be extended to verify complete systems

A mechanized process algebra for verification of device synchronization protocols

We describe the formalization of a process algebra based on CCS within the Higher Order Logic (HOL) theorem-proving system. The representation of four types of device interactions and a correctness proof of the communication between a microprocessor and MMU is presented

Analysis of tethered balloon, ceilometer and class sounding data taken on San Nicolas Island during the FIRE project

During the FIRE Marine Stratocumulus Program on San Nicolas Island, Colorado State University (CSU) and the British Meteorological Office (BMO) operated separate instrument packages on the NASA tethered balloon. The CSU package contained instrumentation for the measurement of temperature, pressure, humidity, cloud droplet concentration, and long and short wave radiation. Eight research flights, performed between July 7 and July 14, are summarized. An analysis priority to the July 7, 8 and 11 flights was assigned for the purposes of comparing the CSU and BMO data. Results are presented. In addition, CSU operated a laser ceilometer for the determination of cloud base, and a CLASS radiosonde site which launched 69 sondes. Data from all of the above systems are being analyzed

Formal verification of a microcoded VIPER microprocessor using HOL

The Royal Signals and Radar Establishment (RSRE) and members of the Hardware Verification Group at Cambridge University conducted a joint effort to prove the correspondence between the electronic block model and the top level specification of Viper. Unfortunately, the proof became too complex and unmanageable within the given time and funding constraints, and is thus incomplete as of the date of this report. This report describes an independent attempt to use the HOL (Cambridge Higher Order Logic) mechanical verifier to verify Viper. Deriving from recent results in hardware verification research at UC Davis, the approach has been to redesign the electronic block model to make it microcoded and to structure the proof in a series of decreasingly abstract interpreter levels, the lowest being the electronic block level. The highest level is the RSRE Viper instruction set. Owing to the new approach and some results on the proof of generic interpreters as applied to simple microprocessors, this attempt required an effort approximately an order of magnitude less than the previous one

Other Challenges in the Development of the Orbiter Environmental Control Hardware

Development of the Space Shuttle orbiter environmental control and life support system (ECLSS) included the identification and resolution of several interesting problems in several systems. Some of these problems occurred late in the program, including the flight phase. Problems and solutions related to the ammonia boiler system (ABS), smoke detector, water/hydrogen separator, and waste collector system (WCS) are addressed

PENGARUH PENAMBAHAN POTONGAN KARUNG PLASTIK SEBAGAI BAHAN CAMPURAN UNTUK MEMPERKUAT TIMBUNAN TANAH LEMPUNG

Terbatasnya lahan untuk pembangunan yang diperlukan mengakibatkan tidak dapat dihindarinya pembangunan di atas tanah lempung seperti tanah yang ada di Indonesia. Oleh karena itu, sangat penting untuk mencampurkan bahan tambahan sebagai campuran ke dalam tanah lempung tersebut untuk meningkatkan kualitas daya dukung tanah pada tanah lempung. Karena banyaknya permintaan karung plastik, limbah karung plastik menjadi semakin banyak, maka peneliti mencoba untuk memanfaatkan serat karung plastik tersebut sebagai bahan campuran pada tanah lempung benda uji. Dengan mencampurkan potongan serat karung plastik ke dalam tanah lempung, diharapkan tanah lempung campuran serat karung plastik tersebut dapat meningkatkan kepadatan tanah dan dapat memperkuat kuat geser tanah. Studi ini meliputi, studi literatur dan penelitian di Laboratorium Mekanika Tanah ITN Malang pada tanggal 7 April – 19 Juli 2019. Tanah benda uji dalam penelitian ini berasal dari Ds. Argotirto, Kec. Sumbermanjing Wetan, Kab. Malang dan bahan campuran potongan serat karung plastik sepanjang ≥ 1cm - ≤ 3cm dengan variasi kadar campuran; 1%, 1,5%, 2%, 2,5%, 3% dari berat total tanah saat kadar air optimum. Penelitian ini meliputi pengujian sifat fisik dan sifat teknis. Pengujian sifat fisik meliputi; Kadar Air Tanah Asli (w), Berat Jenis (Gs), Analisa Saringan, Analisa Hidrometer, Uji Plastisitas (LL, PL, SL), Tingkat Pengembangan, dan Tingkat Keaktifan (Activity). Pengujian sifat teknis meliputi; Compaction Standard dan Modified, Triaxial UU, dan Unconfined Compression, masing-masing pengujian terdiri dari 3 sampel. Dengan dibantu uji hipotesis data untuk mengetahui adanya pengaruh atau tidak adanya pengaruh dalam pengujian tanah lempung campuran serat karung plastik tersebut. Berdasarkan hasil pengujian, tanah benda uji penelitian tersebut termasuk dalam tanah MH (Lanau anorganik atau pasir halus diatomac, atau lanau diatomac, lanau yang elastis). Nilai hasil pengujian campuran serat karung plastik cenderung meningkat dibandingkan tanah tanpa campuran. Nilai tertinggi untuk bahan timbunan mendapatkan prosentase kadar campuran serat karung plastik sebanyak 3% pada pengujian Modified Compaction sebesar; 1,528g/cm3, dengan nilai kadar air (w) sebesar; 26,89%. Pada pengujian Triaxial UU, mendapatkan nilai Kohesi (c) sebesar; 0,350kg/cm², dengan nilai Sudut Geser (φ) sebesar; 6,277 pada kadar campuran 3%. Dan pada pengujian Unconfined Compression, mendapatkan nilai Tegangan Normal (qu) sebesar; 0,681kgf/cm2 pada kadar campuran 1%

Analysis of sounding data from Porto Santo island during ASTEX

November 7, 1992.Includes bibliographical references.We present an analysis of the ASTEX radiosonde data obtained on Porto Santo Island during 1-28 June 1992. The data consists of 203 soundings and is available in two forms-Level I and Level II. The Level I data is the raw data produced by the real time software of the AIR radiosonde system. This data is at irregular pressure and height levels. Level II data consists of processed thermodynamic and wind data at a uniform vertical resolution of 10m, which essentially retains the highest possible vertical resolution in the original raw data. Plots of temperature and dew point temperature are presented for each of the 203 soundings taken during ASTEX. Plots of the 28 day means and of the diurnal variations are also presented. Accessibility of this data via anonymous ftp is also discussed