• Title/Summary/Keyword: Ground Speed Prediction

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Assessment of Rock Mass Properties Ahead of Tunnel Face Using Drill Performance Parameters (천공데이터를 활용한 터널 막장 전방 암반특성 평가)

  • Kim, Kwang-Yeom;Kim, Chang-Yong;Chang, Soo-Ho;Seo, Kyeong-Won;Lee, Seung-Do
    • Explosives and Blasting
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    • v.25 no.1
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    • pp.67-77
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    • 2007
  • The drill monitoring data are useful for the detection of abrupt and unexpected changes in ground renditions. This paper introduces a new approach to how drill performance parameters can be used for the prediction of quantitative rock mass properties ahead of tunnel face and the blasting design. The drill monitoring parameters available for the predictions include the instantaneous advance speed, thrust force, torque, tool pressure and penetration rate. The assessment of the drill monitoring parameters will be able to build a database provided that in-situ drill monitoring informations are accumulated and enable us to make a reasonable blast design based on quantitative assessment of rock mass.

A Study on the Prediction of Sailing Performance for a LNGC based on the AIS Data (AIS 데이터에 기반한 LNGC의 운항 성능 추정 시뮬레이션 연구)

  • You, Youngjun;Kim, Jaehan;Seo, Min-Guk
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.4
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    • pp.275-285
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    • 2017
  • In order to predict the sailing performance of a LNGC during actual operation, it is necessary to consider not only the information about resistance, maneuverability etc. but also the information such as sea route and sailing scenario etc., comprehensively. In this paper, we propose a new approach to conduct the sailing simulation of a LNGC without full scale measurement data. Latitude, longitude, sea route, speed over ground, time in UTC obtained from AIS data are substituted for the measured data. By combining the model test results, design information, and AIS data, prediction of sailing performance is conducted from the coast of southern Taiwan to the coast of Madagascar. The simulation is verified by comparing the calculated time histories of RPM and power with those of measured RPM and power.

Environmental Noise Prediction using Scale Model: A Measurement Methodology

  • Kim, Tae-Min;Han, Jae-Hyun;Kim, Jeung-Tae
    • International Journal of Railway
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    • v.4 no.2
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    • pp.42-49
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    • 2011
  • Today, rolling stock has become a fast and convenient mode of transportation and has witnessed increased demand. But the speed improvement has resulted in increased aerodynamic noise and therefore residential districts near the railroad tracks are exposed to ever increasing noise level. A study on methodologies for measuring and appraising rolling stock's environmental noise has therefore become an important area of endeavor. In the case of the environmental noise, there are no changes in tone so prediction can be made by reducing areas around the railway. The present study explores estimation of the noise around the railway using scale model, and the source of the noise has been investigated as well. The scale model of rolling stock will have to be able to measure high frequency noise and it is required to be generated in a short amount of time. Since popping a balloon or firing a gun fits this requirement the present study analyzed the characteristics of these two different noise sources. Measurement was made in a large vacant lot and the reflection due to the ground was also examined. The method proposed here can be used in the future for predicting the environmental noise of railway vehicles.

A Study of Sound Source to predict Environment Noise in High Speed Train : Scaled model (고속철도 축소모형의 환경소음 예측을 위한 소음원 연구)

  • Kim, Tae-Min;Han, Jea-Hyun;Kim, Jeung-Tae
    • Proceedings of the KSR Conference
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    • 2011.05a
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    • pp.1342-1351
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    • 2011
  • Nowadays rolling stock has become a fast and convenient transportation and increased in its demands. But the improvement of speed has result in increase of aerodynamic noise and therefore residential districts near by the railroad are now constantly suffering from the racket. Thus the study regarding rolling stock's environmental noise measurement and appraisal has become important. The case of environmental noise, there are no changes of tone so prediction can be made by reducing areas around the railway. This is part of the study which estimates the noise around the railway using scaled model, and the source of the noise has been researched on. The scaled model of rolling stock will have to be able to make high frequency and it needs to be spread out in a short amount of time. When popping a balloon or firing a gun fits its condition and this study analyzed the characteristics of these two different noises. Measurement was held on a wide vacant lot and the reflection effect of the ground is additionally examined. It is judged to be used in the future when predicting the environmental noise of railway vehicles.

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A statistical procedure of analyzing container ship operation data for finding fuel consumption patterns (연료 소비 패턴 발견을 위한 컨테이너선 운항데이터 분석의 통계적 절차)

  • Kim, Kyung-Jun;Lee, Su-Dong;Jun, Chi-Hyuck;Park, Kae-Myoung;Byeon, Sang-Su
    • The Korean Journal of Applied Statistics
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    • v.30 no.5
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    • pp.633-645
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    • 2017
  • This study proposes a statistical procedure for analyzing container ship operation data that can help determine fuel consumption patterns. We first investigate the features that affect fuel consumption and develop the prediction model to find current fuel consumption. The ship data can be divided into two-type data. One set of operation data includes sea route, voyage information, longitudinal water speed, longitudinal ground speed, and wind, the other includes machinery data such as engine power, rpm, fuel consumption, temperature, and pressure. In this study, we separate the effects of external force on ships according to Beaufort Scale and apply a partial least squares regression to develop a prediction model.

Study for Prediction of Ride Comfort on the Curve Track by Predictive Curve Detection (사전틸팅제어의 곡선부 주행 승차감 평가 연구)

  • Ko, Tae-Hwan;Lee, Duk-Sang
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.69-74
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    • 2011
  • In the curving detection method by using an accelerometer, the ride comfort in the first car is worse than one in the others due to spend the time to calculate the tilting command and drive the tilting mechanism after entering in the curve. In order to enhance the ride comfort in the first car, the preditive curve detection method which predicts the distance from a train to the starting point of curve by using the GPS, Tachometer, Ground balise and position DB for track. In this study, we predicted and evaluated the ride comfort for predictive curve detection method in transient curves according to the shape and dimension of transient curve and the various driving speed. Also, we predicted the improvement of the ride comfort for predictive curve detection method by comparing with the result of the ride comfort for predictive curve detection method and for curve detection method using an accelerometer in the short transient curve.

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Random Forest Classifier-based Ship Type Prediction with Limited Ship Information of AIS and V-Pass

  • Jeon, Ho-Kun;Han, Jae Rim
    • Korean Journal of Remote Sensing
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    • v.38 no.4
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    • pp.435-446
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    • 2022
  • Identifying ship types is an important process to prevent illegal activities on territorial waters and assess marine traffic of Vessel Traffic Services Officer (VTSO). However, the Terrestrial Automatic Identification System (T-AIS) collected at the ground station has over 50% of vessels that do not contain the ship type information. Therefore, this study proposes a method of identifying ship types through the Random Forest Classifier (RFC) from dynamic and static data of AIS and V-Pass for one year and the Ulsan waters. With the hypothesis that six features, the speed, course, length, breadth, time, and location, enable to estimate of the ship type, four classification models were generated depending on length or breadth information since 81.9% of ships fully contain the two information. The accuracy were average 96.4% and 77.4% in the presence and absence of size information. The result shows that the proposed method is adaptable to identifying ship types.

Development and Wind Speed Evaluation of Ultra High Resolution KMAPP Using Urban Building Information Data (도시건물정보를 반영한 초고해상도 규모상세화 수치자료 산출체계(KMAPP) 구축 및 풍속 평가)

  • Kim, Do-Hyoung;Lee, Seung-Wook;Jeong, Hyeong-Se;Park, Sung-Hwa;Kim, Yeon-Hee
    • Atmosphere
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    • v.32 no.3
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    • pp.179-189
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    • 2022
  • The purpose of this study is to build and evaluate a high-resolution (50 m) KMAPP (Korea Meteorological Administration Post Processing) reflecting building data. KMAPP uses LDAPS (Local Data Assimilation and Prediction System) data to detail ground wind speed through surface roughness and elevation corrections. During the detailing process, we improved the vegetation roughness data to reflect the impact of city buildings. AWS (Automatic Weather Station) data from a total of 48 locations in the metropolitan area including Seoul in 2019 were used as the observation data used for verification. Sensitivity analysis was conducted by dividing the experiment according to the method of improving the vegetation roughness length. KMAPP has been shown to improve the tendency of LDAPS to over simulate surface wind speeds. Compared to LDAPS, Root Mean Square Error (RMSE) is improved by approximately 23% and Mean Bias Error (MBE) by about 47%. However, there is an error in the roughness length around the Han River or the coastline. Accordingly, the surface roughness length was improved in KMAPP and the building information was reflected. In the sensitivity experiment of improved KMAPP, RMSE was further improved to 6% and MBE to 3%. This study shows that high-resolution KMAPP reflecting building information can improve wind speed accuracy in urban areas.

Theoretical Performance Prediction Program of Pulse Detonation Engines (펄스 데토네이션 엔진 이론 성능 예측 프로그램)

  • Kim, Tae-Young;Kim, Ji-Hoon;Choi, Jeong-Yeol
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.42 no.7
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    • pp.552-560
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    • 2014
  • Pulse Detonation Engine(PDE) has been investigated as a next generation propulsion system with the advantages of the higher thermal efficiency by the compression effect and the wide operation ranges from zero speed at ground. In the present study, an efficient theoretical PDE performance prediction program was developed for realistic propellants based on the Endo's theory combining the Chapman-Jouguet detonation theory and expansion process of burnt gas in a constant area tube. The program was validated through the comparison with the experimental data obtained by a ballistic pendulum measurement. PDE performance analyses were carried out for various hydrocarbon fuels and oxidizer compositions by changing the mixture equivalence ratio and initial conditions. Theoretical PDE performance database could be established as a result of the analyses.

Study on the Local Weather Characteristics using Observation Data at the Boseong Tall Tower (보성 종합기상탑 자료를 활용한 국지기상 특성 연구)

  • Hwang, Sung Eun;Lee, Young Tae;Shin, Seung Sook;Kim, Ki Hoon
    • Journal of the Korean earth science society
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    • v.41 no.5
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    • pp.459-468
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    • 2020
  • In this study, the selection criteria for the occurrence of sea breezes in the Boseong area during the spring season (March-May) of 2016-2017 were prepared for the analysis of vertical weather characteristics. For this purpose, wind speed values were determined using the measured precipitation, cloud volume, wind direction, the difference between the ground and sea temperature, a wind Profiler at an altitude of 1 km, and numerical model data. The dates of the sea breezes in Boseong were classified according to the selection criteria, and the spatial and temporal characteristics of the sea breezes were identified by analyzing the time and altitude of the sea breeze and the size of the wind speed. Sea breezes occurred 23 out of 183 days (12%), and in Boseong, at least 1.2 out of 10 spring days exhibited sea breezes. Sea winds ranged from 1200 to 1800 LST, mainly from ground to 700 m altitude during the day. In addition, the maximum wind speed averaged 4.9 m s-1, at an altitude of 40 m at 1600 LST, showing relatively lower values than those in a preceding study. This seems to be owing to the reduction in wind speed due to the complexity of the coastal terrain.