• Title/Summary/Keyword: formal model

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Development of Verification and Conformance Test Generation of Communication Protocol for Railway Signaling Systems

  • Lee, Jae-Ho;Hwang, Jong-Gyu;Seo, Mi-Seon;Kim, Sung-Un;Park, Gwi-Tae
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.358-362
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    • 2004
  • Verification and testing are complementary techniques that are used to increase the level of confidence in the correct functioning of communication systems as prescribed by their specifications. This paper presents an experience of model checking for a formal railway signaling protocol specified in LTS (Labeled Transition System). This formal approach checks deadlock, livelock and reachability for the state and action to verify whether properties expressed in modal logic are true on specifications. We also propose a formal method for semi-automated test case generation for a railway signaling protocol described in I/O FSM (Input/Output Finite State Machine). This enables the generation of more complete and consistent test sequence for conformance testing. The above functions are implemented by C++ language and included within RSPVTE (Railway Signaling Protocol Verification and Testing Environment).

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Formal Analysis of Automatic Train Protection and Block System for Regional Line Using VDM++

  • Xie, Guo;Hei, Xinhong;Mochizuki, Hiroshi;Takahashi, Sei;Nakamura, Hideo
    • International Journal of Railway
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    • v.5 no.2
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    • pp.65-70
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    • 2012
  • This paper introduced a novel railway system, Automatic Train Protection and Block (ATPB) briefly, which is proposed to improve the efficiency of existing regional train lines with low cost in Japan. The biggest superiority of ATPB system is a great use of universal and mature technologies, such as GPS and regular mobile telephone networks, so that there is nearly no increment of trackside equipments in the reconstruction. Then in order to guarantee the system safety, a formal model of ATPB is established and analyzed by formal method VDM++. Firstly, the specification is specified by VDM++ formally without ambiguity. Secondly, its internal consistency is proved by discharging the proof obligations. And finally, its satisfiability is checked by systematic testing, which executes specification and checks the outputs against corresponding inputs.

A Formal Verification Technique for PLC Programs Implemented with Function Block Diagrams (함수 블록 다이어그램으로 구현된 PLC 프로그램에 대한 정형 검증 기법)

  • Jee, Eun-Kyoung;Jeon, Seung-Jae;Cha, Sung-Deok
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.3
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    • pp.211-215
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    • 2009
  • As Programmable Logic Controllers (PLCs) are increasingly used to implement safety critical systems such as nuclear instrumentation & control system, formal verification for PLC based programs is becoming essential. This paper proposes a formal verification technique for PLC program implemented with function block diagram (FBD). In order to verify an FBD program, we translate an FBD program into a Verilog model and perform model checking using SMV model checker We developed a tool, FBD Verifier, which translates FBD programs into Verilog models automatically and supports efficient and intuitive visual analysis of a counterexample. With the proposed approach and the tool, we verified large FBD programs implementing reactor protection system of Korea Nuclear Instrumentation and Control System R&D Center (KNICS) successfully.

Clinical Characteristics of Formal Thought Disorder in Schizophrenia (조현병에서 형식적 사고장애의 임상적 특성)

  • Yang, Chaeyoung;Kim, Han-sung;Kim, Eunkyung;Kim, Il Bin;Park, Seon-Cheol;Choi, Joonho
    • Korean Journal of Biological Psychiatry
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    • v.28 no.2
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    • pp.70-77
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    • 2021
  • Objectives Our study aimed to present the distinctive correlates of formal thought disorder in patients with schizophrenia, using the Clinical Language Disorder Rating Scale (CLANG). Methods We compared clinical characteristics between schizophrenia patients with (n = 84) and without (n = 82) formal thought disorder. Psychometric scales including the CLANG, the Brief Psychiatric Rating Scale (BPRS), the Young Mania Rating Scale (YMRS), the Calgery Depression Scale for Schizophrenia (CDSS) and the Word Fluency Test (WFT) were used. Results After adjusting the effects of age, sex and total scores on the BPRS, YMRS and WFT, the subjects with disorganized speech presented significantly higher score on the abnormal syntax (p = 0.009), lack of semantic association (p = 0.005), discourse failure (p < 0.0001), pragmatics disorder (p = 0.001), dysarthria (p < 0.0001), and paraphasic error (p = 0.005) items than those without formal thought disorder. With defining the mentioned item scores as covariates, binary logistic regression model predicted that discourse failure (adjusted odds ratio [aOR] = 5.88, p < 0.0001) and pragmatics disorder (aOR = 2.17, p = 0.04) were distinctive correlates of formal thought disorder in patients with schizophrenia. Conclusions This study conducted Clinician Rated Dimensions of Psychosis Symptom Severity (CRDPSS) and CLANG scales on 166 hospitalized schizophrenia patients to explore the sub-items of the CLANG scale independently related to formal thought disorders in schizophrenia patients. Discourse failure and pragmatics disorder might be used as the distinctive indexes for formal thought disorder in patients with schizophrenia.

Authorization Model with Provisions and Obligations in XML

  • Kim Suhee;Park Jongjin
    • Proceedings of the IEEK Conference
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    • summer
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    • pp.355-360
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    • 2004
  • With the growing acceptance of XML technologies, XML will be the most common tool for all data manipulation and data transmission. Meeting security requirements for privacy, confidentiality and integrity is essential in order to move business online and it is important for security to be integrated with XML solutions. Many policies require certain conditions to be satisfied and actions to be performed before or after a decision is made. Binary yes/no decision to an access request is not enough for many applications. These issues were addressed and formalized as provisions and obligations by Betti et Al. In this paper, we propose an authorization model with provisions and obligations in XML. We introduce a formal definition of authorization policy and the issues involving obligation discussed by Betti et Al. We use the formal model as a basis to develop an authorization model in XML. We develop DTDs in XML for main components such as authorization request, authorization policy and authorization decision. We plan to develop an authorization system using the model proposed.

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A Computational Model for Discussion Activities on Electronic BBS (전자게시판의 토의 활동에 대한 계산 모델)

  • Moon, Gyo-Sik
    • Journal of the Korea Computer Industry Society
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    • v.6 no.2
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    • pp.373-378
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    • 2005
  • Computer-Mediated Communication (CMC) based on electronic bulletin board system (e-BBS) has been widely used for various educational purposes since the advent of the Internet. Instructors can achieve pedagogical goals by analyzing the contents of postings. They can be benefited technically from analytic information on discussion activities. Studies on content analysis and social presence in communication have been traditionally done by social studies. However, researches on computational and logical analysis of the phenomenon are rare. To do that we propose a formal model to represent and analyze communication activities logically. The model consists of interactivity vector providing a formal representation of discussion activities and interactivity chart providing a graphical representation of interactivity vector. The formal approach can be used as a useful technical assistance to analyze and compare discussion groups computationally.

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A Concept Model Design of a Home Automation System Using Intelligent Mobile Robot (지능형 이동 로봇을 이용한 홈오토메이션 시스템 모델 제안 및 구현)

  • Ahn Ho Seok;Choi Jin Young
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2005.04a
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    • pp.221-224
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    • 2005
  • This paper proposes the system model that is more efficient and active than formal home automation system and it can conquer the limits of formal one using intelligent mobile robot. This system uses specialized intelligent mobile robot for home environment and the robot moves around home instead of human. We call the system model to HAuPIRS (Home Automation system using PDA based Intelligent Robot System). HAuPIRS control architecture is composed three parts and each part is User Level, Cognitive Level, Executive Level. It is easy to use system and possible to extend the home apparatusfrom new technology. We made the PBMoRo System (PDA Based Mobile Robot System) based on HAuPIRS architecture and verified the efficiency of the system model.

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The Quality Characteristics Based on Customer-required Attributes of Middle and Elderly Women's Formal Knitwear (고객요구속성을 반영한 중.노년층 니트정장 품질특성)

  • Lee, Yoon-Mee;Park, Jae-Ok
    • Journal of the Korean Society of Clothing and Textiles
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    • v.34 no.5
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    • pp.844-855
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    • 2010
  • An important issue for the improvement of product quality is to identify and understand the customer-required attributes of a product. This paper identifies and analyzes customer-required attributes of formal knitwear for middle age and elderly women through the use of the Kano model in order to develop competitive products. Various research methods were used in this study. Customer voices for formal knitwear were collected by means of brainstorming and in-depth interviews. The collected customer voices were transformed into customer-required attributes with the use of an affinity diagram. In addition, the data was collected by means of a questionnaire and was statistically analyzed to examine the dimensions of customer-required attributes on the basis of the Kano model. The results are as follows. Five categories of customer-required attributes were identified (symbolism, aesthetic, fitness, usefulness, and maintenance). The analysis based on the Kano model identifies a strong one-dimensional quality in all of the categories of customer-required attributes and the attractive quality that includes a one-dimensional quality in the categories of fitness and usefulness. The findings of this study demonstrate the applicability of the affinity diagram for apparel that educates formal knitwear developers of the customer-required attributes that they should strategically focus on in order to develop competitive products.

LTS Semantics Model of Event-B Synchronization Control Flow Design Patterns

  • Peng, Han;Du, Chenglie;Rao, Lei;Liu, Zhouzhou
    • Journal of Information Processing Systems
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    • v.15 no.3
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    • pp.570-592
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    • 2019
  • The Event-B design pattern is an excellent way to quickly develop a formal model of the system. Researchers have proposed a number of Event-B design patterns, but they all lack formal behavior semantics. This makes the analysis, verification, and simulation of the behavior of the Event-B model very difficult, especially for the control-intensive systems. In this paper, we propose a novel method to transform the Event-B synchronous control flow design pattern into the labeled transition system (LTS) behavior model. Then we map the design pattern instantiation process of Event-B to the instantiation process of LTS model and get the LTS behavior semantic model of Event-B model of a multi-level complex control system. Finally, we verify the linear temporal logic behavior properties of the LTS model. The experimental results show that the analysis and simulation of system behavior become easier and the verification of the behavior properties of the system become convenient after the Event-B model is converted to the LTS model.

Assessment of the uncertainty in the SWAT parameters based on formal and informal likelihood measure (정형·비정형 우도에 의한 SWAT 매개변수의 불확실성 평가)

  • Seong, Yeon Jeong;Lee, Sang Hyup;Jung, Younghun
    • Journal of Korea Water Resources Association
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    • v.52 no.11
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    • pp.931-940
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    • 2019
  • In hydrologic models, parameters are mainly used to reflect hydrologic elements or to supplement the simplified models. In this process, the proper selection of the parameters in the model can reduce the uncertainty. Accordingly, this study attempted to quantify the uncertainty of SWAT parameters using the General Likelihood Uncertainty Estimation (GLUE). Uncertainty analysis on SWAT parameters was conducted by using the formal and informal likelihood measures. The Lognormal function and Nash-Sutcliffe Efficiency (NSE) were used for formal and informal likelihood, respectively. Subjective factors are included in the selection of the likelihood function and the threshold, but the behavioral models were created by selecting top 30% lognormal for formal likelihood and NSE above 0.5 for informal likelihood. Despite the subjectivity in the selection of the likelihood and the threshold, there was a small difference between the formal and informal likelihoods. In addition, among the SWAT parameters, ALPHA_BF which reflects baseflow characteristics is the most sensitive. Based on this study, if the range of SWAT model parameters satisfying a certain threshold for each watershed is classified, it is expected that users will have more practical or academic access to the SWAT model.