• Title/Summary/Keyword: Observation method

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A Study on the Digital Filter Design using Software for Analysis of Observation Data in Radio Astronomy (전파천문 관측데이터 분석을 위해 소프트웨어를 이용한 디지털필터 설계에 관한 연구)

  • Yeom, Jae-Hwan;Oh, Se-Jin;Roh, Duk-Gyoo;Oh, Chung-Sik;Jung, Dong-Kyu;Shin, Jae-Sik;Kim, Hyo-Ryoung;Hwang, Ju-Yeon
    • Journal of the Institute of Convergence Signal Processing
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    • v.16 no.4
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    • pp.175-181
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    • 2015
  • In this paper, we propose a design method for a digital filter using software in order to analyze the radio astronomy observation data. Recently the analysis method for radio astronomy observing system is transferring from hardware to software by developing of state-of-the-art of computer system. The existing hardware system is not able to easily change the specification because it is implemented to meet special requirements and it takes a high cost and time. In case of software, however, it has an advantage to implement with small cost if open software is used, and flexibly changes to satisfy the desired specification. But, in order to analyze the massive data like radio astronomy with software, the good performance system is needed for computer. Therefore, this paper proposes a digital filter design method using software with the same performance as that of digital filter implemented with hardware in observation system which is operated by the KVN(Korean VLBI Network). To design a digital filter, the proposed method is performed with standard C language and the simulation is conducted with GNU(GNU's Not Unix) Octave and investigated to show its effectiveness. In addition, for the high speed operation of the designed digital filter, the SSE(Streaming SIMD Extensions) library is adopted for available parallel operation. By the proposed digital filter, the digital filtering is performed for the wide band observation data in the KVN observation mode, the filtering result of narrow band observation has no ripple inside of stop band, and confirmed the effectiveness of the proposed method.

Themal Fatigue Behavior of Alumina Ceramics (알루미나 세라믹스의 열피로 거동)

  • 정우찬;한봉석;이홍림;이형직
    • Journal of the Korean Ceramic Society
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    • v.35 no.10
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    • pp.1094-1100
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    • 1998
  • The thermal fatigue behavior of alumina ceramics was investigated by water quenching method. Single-quench thermal shock tests were performed to decide the critical thermal shock temperature difference ($\Delta$Tc) which was found to be 225$^{\circ}C$ Cyclic thermal shock fatigue tests were performed at temperature diff-erences of 175$^{\circ}C$, 187$^{\circ}C$ and 200$^{\circ}C$ respectively. After cyclic thermal shock fatigue test the distributions of retained strength and crack were observed. Retained strength was measured by four point bending method and crack observation method bydye penetration. In terms of the retained strength distribution the critical number of thermal shock cycles(Nc) were 7 for $\Delta$T=200$^{\circ}C$, 35 for $\Delta$T=187$^{\circ}C$ and 180for $\Delta$T=175$^{\circ}C$ respec-tively. In terms of the crack observation the critical number of thermal shock cycles were 5 for $\Delta$T==200$^{\circ}C$ 20 for $\Delta$T==187$^{\circ}C$ and 150 for $\Delta$T=175$^{\circ}C$ respectively. The difference of Nc investigated by two different methods is due to the formation of the longitudinal cracks which had no effect on the four point bending strength. Therefore the thermal fatigue behavior of alumina ceramics could be more accurately described by the crack observation method than the retained strength measurement method.

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Effects of Observation Network Density Change on Spatial Distribution of Meteorological Variables: Three-Dimensional Meteorological Observation Project in the Yeongdong Region in 2019 (관측망 밀도 변화가 기상변수의 공간분포에 미치는 영향: 2019 강원영동 입체적 공동관측 캠페인)

  • Kim, Hae-Min;Jeong, Jong-Hyeok;Kim, Hyunuk;Park, Chang-Geun;Kim, Baek-Jo;Kim, Seung-Bum
    • Atmosphere
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    • v.30 no.2
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    • pp.169-181
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    • 2020
  • We conducted a study on the impact of observation station density; this was done in order to enable the accurate estimation of spatial meteorological variables. The purpose of this study is to help operate an efficient observation network by examining distributions of temperature, relative humidity, and wind speed in a test area of a three-dimensional meteorological observation project in the Yeongdong region in 2019. For our analysis, we grouped the observation stations as follows: 41 stations (for Step 4), 34 stations (for Step 3), 17 stations (for Step 2), and 10 stations (for Step 1). Grid values were interpolated using the kriging method. We compared the spatial accuracy of the estimated meteorological grid by using station density. The effect of increased observation network density varied and was dependent on meteorological variables and weather conditions. The temperature is sufficient for the current weather observation network (featuring an average distance about 9.30 km between stations), and the relative humidity is sufficient when the average distance between stations is about 5.04 km. However, it is recommended that all observation networks, with an average distance of approximately 4.59 km between stations, be utilized for monitoring wind speed. In addition, this also enables the operation of an effective observation network through the classification of outliers.

Tracking moving objects using particle filter and edge observation model (에지 관측 모델과 파티클 필터를 이용한 이동 객체 추적)

  • Kim, Hyoyeon;Kim, Kisang;Choi, Hyung-Il
    • Journal of Internet Computing and Services
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    • v.17 no.3
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    • pp.25-32
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    • 2016
  • In this paper, we propose a method that is tracking an object in real time using particle filter and the observation model with edge. First of all, the proposed method defines the object to be tracked in the initial frame. Then, it generates the edge observation model for the object to be tracked and a set of particles. It calculates the weight by comparing the average of the middle distance in eight-way of particle filter edge model with that in edge observation model, and then updates the weight with the calculated value. After resampling particles using the updated weights, it estimates the current location of the tracked object. Finally, this paper demonstrates the performance of the stable tracking through comparison with the existing method by using a number of experimental data.

Monitoring Techniques for Active Volcanoes (활화산의 감시 기법에 대한 연구)

  • Yun, Sung-Hyo;Lee, Jeong-Hyun;Chang, Cheol-Woo
    • The Journal of the Petrological Society of Korea
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    • v.23 no.2
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    • pp.119-138
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    • 2014
  • There are various ways to monitor active volcanoes, such as the method of observing the activity of a volcano with the naked eye, the method of referring to the past eruptive history based on the historic records and the method of monitoring volcanoes by using observation equipment. The most basic method from the observation equipment-using methods to monitor volcanoes is seismic monitoring. In addition to this, the ways to monitor volcanoes are as follows: resonance observation which may be effective to remove artificial noises from the seismic activities that are recorded in the seismograph, ground deformation by using precision leveling, electronic distance measurement, tiltmeter, GPS, and InSAR observation method, volcanic gas monitoring, hydrologic and meteorological monitoring, and other geophysical monitoring methods. These monitoring methods can make volcanic activities effectively monitored, determine the behavior of magmas in magma chambers and help predict the future volcanic eruptions more accurately and early warning, thus, minimize and mitigate the damage of volcanic hazards.

A study On An Identification of Interactions In A Nonreplicated Two-Way Layout With $L_1$-Estimation

  • Lee, Ki-Hoon
    • Communications for Statistical Applications and Methods
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    • v.7 no.1
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    • pp.119-128
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    • 2000
  • This paper proposes a method for detecting interactions in a two-way layout with one observation per cell. The identification of interactions in the model is not clear for they are confounding with error terms. The $L_1$-Estimation is robust with respect to a y-direction outlier in linear model so we are able to estimate main effects without affection of interactions, If an observation is classified as an outlier we conclude it contains an interaction. An empirical study compared with a classical method is performed.

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Bias Correction for Aircraft Temperature Observation Part I: Analysis of Temperature Bias Characteristics by Comparison with Sonde Observation (항공기 온도 관측 자료의 편향 보정 Part I: 존데와 비교를 통한 온도 편향 특성 분석)

  • Kwon, Hui-nae;Kang, Jeon-ho;Kwon, In-Hyuk
    • Atmosphere
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    • v.28 no.4
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    • pp.357-367
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    • 2018
  • In this study, the temperature bias of aircraft observation was estimated through comparison with sonde observation prior to developing the temperature bias correction method at the Korea Institute of Atmospheric Prediction Systems (KIAPS). First, we tried to compare aircraft temperature with collocated sonde observations at 0000 UTC on June 22, 2012. However, it was difficult to estimate the temperature bias due to the lack of samples and the uncertainty of the sonde position at high altitudes. Second, we attempted a background innovation comparison for sonde and aircraft using KIAPS Package for Observation Processing (KPOP). The one month averaged background innovation shows the aircraft temperature have a warm bias against sonde for all levels. In particular, there is a globally distinct warm bias about 0.4 K between 200 hPa and 300 hPa corresponding to flight level. Spatially, most of the areas showed the warm bias except for below 300 hPa in some part of China at 0000 and 1200 UTC and below 850 hPa in Australia at 0000 UTC. In general, the temperature bias was larger at 1200 UTC than 0000 UTC. Based on the estimated temperature bias, we have applied the static bias correction method to the aircraft temperature observation. As a result, the warm bias of the aircraft temperature has decreased at most levels, but a slight cold bias has occurred in some areas.

The potential of non-movement behavior observation method for detection of sick broiler chickens

  • Hyunsoo Kim;Woo-Do Lee;Hyung-Kwan Jang;Min Kang;Hwan-Ku Kang
    • Journal of Animal Science and Technology
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    • v.65 no.2
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    • pp.441-458
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    • 2023
  • The poultry industry, which produces excellent sources of protein, suffers enormous economic damage from diseases. To solve this problem, research is being conducted on the early detection of infection according to the behavioral characteristics of poultry. The purpose of this study was to evaluate the potential of a non-movement behavior observation method to detect sick chickens. Forty 1-day-old Ross 308 males were used in the experiments, and an isolator equipped with an Internet Protocol (IP) camera was fabricated for observation. The chickens were inoculated with Salmonella enterica serovar Gallinarum A18-GCVP-014, the causative agent of fowl typhoid (FT), at 14 days of age, which is a vulnerable period for FT infection. The chickens were continuously observed with an IP camera for 2 weeks after inoculation, chickens that did not move for more than 30 minutes were detected and marked according to the algorithm. FT infection was confirmed based on clinical symptoms, analysis of cardiac, spleen and liver lesion scores, pathogen re-isolation, and serological analysis. As a result, clinical symptoms were first observed four days after inoculation, and dead chickens were observed on day six. Eleven days after inoculation, the number of clinical symptoms gradually decreased, indicating a state of recovery. For lesion scores, dead chickens scored 3.57 and live chickens scored 2.38. Pathogens were re-isolated in 37 out of 40 chickens, and hemagglutination test was positive in seven out of 26 chickens. The IP camera applied with the algorithm detected about 83% of the chickens that died in advance through non-movement behavior observation. Therefore, observation of non-movement behavior is one of the ways to detect infected chickens in advance, and it appears to have potential for the development of remote broiler management system.