• Title/Summary/Keyword: law of similarity

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Verification of Flight Control Law Similarity and HILS Environment Reliability for Fighter Aircraft (전투기급 비행제어법칙 상사성 및 HILS 환경 신뢰성 검증)

  • Ahn, Seong-Jun;Kim, Chong-Sup;Cho, In-Je;Lee, Eun-Yong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.7
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    • pp.701-708
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    • 2009
  • The flight control law of developed flight control computer(DFLCC) is developed based on operation flight program of advanced trainer aircraft full scale development final configuration. The flight control law design is used common use development tool in GUI(Graphic User Interface) environment. The flight control law transformed to C-Code is reflected in OFP. The OFP is verified by the standardized verification process. But, before standardized verification process, we need preliminary verification process such as similarity of flight control law and reliability of developed HILS. Similarity of flight control law is verified by comparing the aircraft response of advanced trainer aircraft and those of the developed control law. Also, reliability of developed HILS is verified by comparing the aircraft response of HILS and Non-real time simulation result. This paper verifies similarity of developed control law and reliability of HILS environment as comparing aircraft response.

Experimental validation of simulating natural circulation of liquid metal using water

  • Lee, Min Ho;Jerng, Dong Wook;Bang, In Cheol
    • Nuclear Engineering and Technology
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    • v.52 no.9
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    • pp.1963-1973
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    • 2020
  • Liquid metal-cooled reactors use various passive safety systems driven by natural circulation. Investigating these safety systems experimentally is more advantageous by using a simulant. Although numerous experimental approaches have been applied to natural circulation-driven passive safety systems using simulants, there has been no clear validation of the similarity law. To validate the similarity law experimentally, SINCRO-V experiment was conducted using Wood's metal and water for simulant of the Wood's metal. A pair of SINCRO-V facilities with length-scale ratio of 14.1:1 for identical Bo' was investigated, which was the main similarity parameter in temperature field simulation. In the experimental range of 0.2-1.0% of decay heat, the temperature distribution characteristics of the small water facility were very similar to that of the large Wood's metal facility. The temperature of the Wood's metal predicted by the water experiment showed good agreement with the actual Wood's metal temperature. Despite some error factors like discordance of Gr' and property change along the temperature, the water experiment predicted the Wood's metal temperature with an error of 27%. The validity of the similarity law was confirmed by the SINCRO-V experiments.

Study on Design of Air-water Two-phase Flow Centrifugal Pump Based on Similarity Law

  • Matsushita, Naoki;Furukawa, Akinori;Watanabe, Satoshi;Okuma, Kusuo
    • International Journal of Fluid Machinery and Systems
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    • v.2 no.2
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    • pp.127-135
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    • 2009
  • A conventional centrifugal pump causes a drastic deterioration of air-water two-phase flow performances even at an air-water two-phase flow condition of inlet void fraction less than 10% in the range of relatively low water flow rate. Then we have developed a two-phase flow centrifugal pump which consists of a tandem arrangement of double rotating cascades and blades of outer cascade have higher outlet angle more than $90^{\circ}$. In design of the two-phase flow pump for various sized and operating conditions, similarity relations of geometric dimensions to hydraulic performances is very useful. The similarity relations of rotational speed, impeller diameter and blade height are investigated for the developed impeller in the present paper. As the results, the similarity law of rotational speed and impeller diameter is clarified experimentally even in two-phase flow condition. In addition, influences of blade height on air-water two-phase flow performances indicate a little difference from the similarity relations.

Application of two different similarity laws for the RVACS design

  • Min Ho Lee;Ji Hwan Hwang;Ki Hyun Choi;Dong Wook Jerng;In Cheol Bang
    • Nuclear Engineering and Technology
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    • v.54 no.12
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    • pp.4759-4775
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    • 2022
  • The RVACS is a versatile and robust safety system driven by two natural circulations: in-vessel coolant and ex-vessel air. To observe interaction between the two natural circulations, SINCRO-IT facility was designed with two different similarity laws simultaneously. Bo' based similarity law was employed for the in-vessel, while Ishii's similarity law for the ex-vessel excluding the radiation. Compared to the prototype, the sodium and air system, SINCRO-IT was designed with Wood's metal and air, having 1:4 of the length reduction, and 1.68:1 of the time scale ratio. For the steady state, RV temperature limit was violated at 0.8% of the decay heat, while the sodium boiling was predicted at 1.3%. It showed good accordance with the system code, TRACE. For an arbitrary re-criticality scenario with RVACS solitary operation, sodium boiling was predicted at 25,100 s after power increase from 1.0 to 2.0%, while the system code showed 30,300. Maximum temperature discrepancy between the experiments and system code was 4.2%. The design and methodology were validated by the system code TRACE in terms of the convection, and simultaneously, the system code was validated against the simulating experiments SINCRO-IT. The validated RVACS model could be imported to further accident analysis.

A Comparative Study Arbitral A ward under the Arbitral Laws between Korea and Japan (한.일 중재법상 중재판정의 비교법적 고찰)

  • Choi, Seok-Beom;Jung, Jae-Woo;Kim, Tae-Hwan
    • Journal of Arbitration Studies
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    • v.16 no.1
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    • pp.81-119
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    • 2006
  • The parties in the trade can have full autonomy and can resolve disputes independently, impartially and without delay by selecting arbitration by agreement. Korea and Japan had revised their Arbitration Laws to incorporate as many provisions of the 1985 UNCITRAL Model Law as possible. Japan had amended its century-old arbitration law, becoming the 45th country to adopt the UNCITRAL Model Law on International commercial arbitration. New Arbitration Law was enacted as Law No.138 of 2003 and effective on March 1, 2004, is applicable to both national and international arbitration. Korea had amended its arbitration law on December 31, 1999 and its New Arbitration Law incorporates the most of the 1985 UNCITRAL Model Law as Japan. Arbitration must be popular in resolving international commercial disputes in Northeast Asian bloc in order to increase the volume of intra-trade in the Northeast Asian bloc. But in order for the parties to make use of arbitration in the bloc, the arbitration laws of nations in the bloc must have similarity and unification. As Korea and Japan playes important roles in the bloc, both nations's arbitration laws must be studied in view of similarity and difference to unify both nations' arbitration laws by way of showing an example. Therefore, this paper deals with both nations' arbitration laws in view of comparative law to unify their arbitration laws and Northeast Asian Nations' arbitration laws.

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Thrust Profile Prediction for a Vertical Launching Missile using Similarity Law (상사법칙을 이용한 수직발사 유도탄 추력곡선예측)

  • Cho, Sung-Jin;Kim, Eul-Gon;Ahn, Jo-Young
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.1
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    • pp.55-61
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    • 2009
  • In this paper, a thrust prediction method for a developing vertical launching missile is proposed through considering a verified vertical launching missile(a baseline missile) as a model. In order to predict thrust profile of a developing vertical launching missile, both Similarity law and Pi theory are applied to the model. By comparing prediction results based on the 6-DOF program of a baseline missile with simulation results of a developing vertical launching missile, the proposed method has been indirectly verified.

Analytical Study on Performance Evaluation of Large-Sized Silencer using Geometric Similarity Law (기하상사법을 이용한 대형 소음기의 성능평가에 관한 해석적 연구)

  • Yang, Jun-Hyuk;Lee, Boo-Youn;Kim, Won-Jin
    • Journal of Advanced Marine Engineering and Technology
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    • v.34 no.2
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    • pp.275-281
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    • 2010
  • In this paper, a geometric similarity law is introduced to the performance test of a large-sized silencer used in ship engine or plant system. A test of scale-down model enable to yield the cost and time saving in developing large-sized silencer considerably. Two types of silencer, resonator and expansion chamber, were analyzed by a theoretical method and an acoustical FEM(finite element method) in order to obtain geometric similarity variables. A method is proposed to estimate the transmission loss of prototype model using the test results of scale-down model. Two actual large-sized silencer, which consist of resonator and expansion chamber, were analysed by an acoustical FE analysis. Consequently, the proposed method predicts effectively the performance of prototype silencers using those of scale-down models.

Similarity rule of Seepage failure by Centrifuge model test (원심모형시험기를 이용한 사면의 침투 및 파괴에 관한 상사법칙의 검토)

  • Kim, Jae-Young;Jun, Tohda
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.313-318
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    • 2004
  • When plan breakdown by permeation of fill dam, bank by original decision scale model test of sound, original decision scale model test of sound that destroy having used water was carried out. And original decision scale model test of sound that use viscous fluid is carried out, but doubt remains in experiment result in state that verification of law of similarity is not achieved. In this study, verified according to Modeling of Models' method effecting law of similarity to use n ship horoscope solution of water.

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Evaluation of Similarity Analysis of Newspaper Article Using Natural Language Processing

  • Ayako Ohshiro;Takeo Okazaki;Takashi Kano;Shinichiro Ueda
    • International Journal of Computer Science & Network Security
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    • v.24 no.6
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    • pp.1-7
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    • 2024
  • Comparing text features involves evaluating the "similarity" between texts. It is crucial to use appropriate similarity measures when comparing similarities. This study utilized various techniques to assess the similarities between newspaper articles, including deep learning and a previously proposed method: a combination of Pointwise Mutual Information (PMI) and Word Pair Matching (WPM), denoted as PMI+WPM. For performance comparison, law data from medical research in Japan were utilized as validation data in evaluating the PMI+WPM method. The distribution of similarities in text data varies depending on the evaluation technique and genre, as revealed by the comparative analysis. For newspaper data, non-deep learning methods demonstrated better similarity evaluation accuracy than deep learning methods. Additionally, evaluating similarities in law data is more challenging than in newspaper articles. Despite deep learning being the prevalent method for evaluating textual similarities, this study demonstrates that non-deep learning methods can be effective regarding Japanese-based texts.

Hack's Law and the Geometric Properties of Catchment Plan-form (Hack의 법칙과 집수평면의 기하학적 특성)

  • Kim, Joo-Cheol;Lee, Sang-Jin
    • Journal of Korea Water Resources Association
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    • v.42 no.9
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    • pp.691-702
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    • 2009
  • This study makes a systematic approach to Hack's law considering self-affinity and self-similarity of natural basins as well as the elongation of corresponding catchment-plan forms. Catchment-plan forms extracted from DEM appear to be the population come from the interactions of 2 hypotheses on Hack's law. It is judged that the elongation measures based on inertia moments are more intuitive than the ones based on main channel lengths. The exponent of Hack's law, h, seems to be similar to the result of Gray's study (1961). However Hurst exponent, H, being 0.96 imply that catchment-plan forms considered in this study have isotropic increasing properties with scale. From this point of view it is inferred that the shapes of the basins in this study would be more affected from self-similarity of main channel lengths than self-affinity of catchment-plan forms.