• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.3
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• pp.79-86
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• 2001

The six-components force measurements systems for rocket motors are used to measure multi components force generated by TVC(Thrust Vector Control) motors. This paper suggested the modeling scheme which is used in preliminary design and test analysis procedure and which can be applied to the existing other test stand in operation. The model whose parameters are determined by least square method makes the design engineer build the test stand to satisfy all kinds of requirements such as accuracy, operating condition and structural stability without tradeoff among the requirements. The experimental results shows that the proposed model has better accurate performances than those of other existing model.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.5
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• pp.31-39
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• 2016

This paper is studied on the effect of the bolt joint stiffness on the Thrust Measurement Stand(TMS). TMS is a test stand for thrust performance of the propulsion system, which depends on two factors: The $1^{st}$ is the parallel degree between directions of the thrust vector and action lines of the corresponding measuring load cells for the vector, and the $2^{nd}$ is the orthogonality between action lines of the measuring load cells. Therefore, it is essential to maintain the original shape of the TMS under operating conditions. In this paper, it is examined how the geometric tolerance of the bolt joints and threads of the load cell trains affect the performance of the TMS. Also, some techniques to overcome related problems are proposed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.04a
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• pp.13-13
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• 2000

일반적으로 고체추진 로켓 모타의 개발단계 때 공통적으로 수행되는 주시험(main test)으로는 추력, 압력, 회전률 등의 성능측정을 하기 위한 정적연소시험(static firing test), 내부 정수압(hydrostatic pressure)에 의한 폭발 압력 시험, 연소중이나 연소 후 케이스에 대한 굽힘 강성 시험, 이외에 노화 시험, 환경시험 등이 요구된다. 그러나 신궁과 같은 휴대용 대공 시스템의 추진기관 개발의 경우에는 사수를 보호하기 위해 여러 가지 안전장치들이 설계되고, 이러한 장치들의 성능에 대한 요구 조건들을 확인하기 위한 특수시험(specific test)들이 필요하게 된다. 이러한 특수시험을 위한 각종 시험대들을, 위에서 언급한 주시험을 위해 사용되는 정적시험대(static test bench)들과 구분하기 위해 동적 시험대(DTB : Dynamic Test Bench)라고 한다. 본 연구에서는 신궁 추진기관의 사출모타 점화에서 비행모타 점화에 이르는 일련의 비행절차를 확인하기 위한 동적 시험대 설계 및 제작, 계측장치 구성 및 데이터 획득 방법 등에 관한 내용을 소개하며, 동적 시험대에서 수회에 걸쳐 수행된 동적 시험 결과를 분석/정리하였다.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.4
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• pp.9-15
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• 2004

The measured thrust could be distorted because of the transient response of thrust stand during combustion of rocket motor. As a result of the distorted thrust, it is not easy for us to know the values of thrust peak and thrust duration time. Therefore, it is of great importance to compute the true thrust from the measured thrust. In this study the method to eliminate the transient response from the measured thrust using only the measured thrust was Proposed, and also experimental data were used to approve the proposed method. The result showed that the proposed method would be available to compute the true thrust.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.3
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• pp.73-81
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• 2006

In order to evaluate the thrust of a propulsion system, generally the captive thrust stand is used Based on the applied propulsion system, the various captive ways between thrust stand and the propulsion system are considered. In this paper, the effect of motor deformation generated during firing in horizontal thrust stand on the measured thrust is theoretically derived from classical beam theory. New flexure performance index is defined and estimated on the basis of the thrust measurement error. Its result is good agreement with numerical result of ABAQUS. This study showed that measurement reliability and safety of test can be highly upgraded, in case of two flexure-type captive thrust stand.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.1
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• pp.9-17
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• 2006

The thrust measurement systems(TMS) with high accuracy are required in rockery, according to develop the high precise guided space vehicle. For obtaining high accuracy, the basic concepts and the necessary technology which have been acquired through many experiences of TMS are summarized, and the design methodology for practical use in ADD is presented. In this paper, the parameters against accuracy of TMS are discussed, and the improving methods are suggested. Through this application example, the design methodology of ADD is shown its superiority in TMS.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.3
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• pp.13-19
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• 2007

This paper described design method to minimize the crosstalk effect of multiaxis thrust measurement stand which can measure the thrust vector control performance of Solid Rocket Motor. This paper presents a theoretical solution for predicting the magnitude of crosstalk and calculates design sensitivity. The results indicate that the most important parameter of crosstalk is the displacement of flexure-loadcell-flexure assembly. And shape, dimension and mechanical properties of flexure and loadcell can also influence the magnitude of crosstalk.

• The Transactions of the Korea Information Processing Society
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• v.1 no.1
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• pp.1-13
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• 1994

The Temporal Database Management Testbed supports valid and transaction time. In this paper, we discuss the design and implementation of a testbed of a temporal database management system in main memory. The testbed consists of a syntactic analyzer, a semantic analyzer, a code generator, and an interpreter. The syntactic analyzer builds a parse tree from a temporal query. The semantic analyzer then checks it for correctness against the system catalog. The code generator builds an execution tree termed ann update network. We employ an incremental view materialization for the execution tree. After building the execution tree, the interpreter activates each node of the execution tree. Also, the indexing structure and the concurrency control are discussed in the testbed.

• Monthly Korean Chicken
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• v.2 no.12 s.18
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• pp.1-1
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• 1996

• Journal of the Korean Society for Railway
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• v.20 no.5
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• pp.577-587
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• 2017

In the design process of dynamic characteristics of a railway vehicle, demand for analysis, testing and estimation methods of running stability are increasing as railway vehicle speed is increasing. Critical speed tests and estimation have been carried out using computer simulation or special test facilities, like roller rigs, because real track testing at critical speed is very dangerous. This paper introduces a test and assessment method for critical speed and estimates the validity using several roller rig tests. The test results show that it is difficult to estimate the critical speed using safety and instability assessment method in UIC 518, but that there is good agreement between the reduction of the equivalent damping ratio and the critical speed.