• Title/Summary/Keyword: low probability detection

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Experimental results on Shape Reconstruction of Underwater Object Using Imaging Sonar (영상 소나를 이용한 수중 물체 외형 복원에 관한 기초 실험)

  • Lee, Yeongjun;Kim, Taejin;Choi, Jinwoo;Choi, Hyun-Taek
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.10
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    • pp.116-122
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    • 2016
  • This paper proposes a practical object shape reconstruction method using an underwater imaging sonar. In order to reconstruct the object shape, three methods are utilized. Firstly, the vertical field of view of imaging sonar is modified to narrow angle to reduce an uncertainty of estimated 3D position. The wide vertical field of view makes the incorrect estimation result about the 3D position of the underwater object. Secondly, simple noise filtering and range detection methods are designed to extract a distance from the sonar image. Lastly, a low pass filter is adopted to estimate a probability of voxel occupancy. To demonstrate the proposed methods, object shape reconstruction for three sample objects was performed in a basin and results are explained.

Complex Segregation Analysis of Categorical Traits in Farm Animals: Comparison of Linear and Threshold Models

  • Kadarmideen, Haja N.;Ilahi, H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.8
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    • pp.1088-1097
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    • 2005
  • Main objectives of this study were to investigate accuracy, bias and power of linear and threshold model segregation analysis methods for detection of major genes in categorical traits in farm animals. Maximum Likelihood Linear Model (MLLM), Bayesian Linear Model (BALM) and Bayesian Threshold Model (BATM) were applied to simulated data on normal, categorical and binary scales as well as to disease data in pigs. Simulated data on the underlying normally distributed liability (NDL) were used to create categorical and binary data. MLLM method was applied to data on all scales (Normal, categorical and binary) and BATM method was developed and applied only to binary data. The MLLM analyses underestimated parameters for binary as well as categorical traits compared to normal traits; with the bias being very severe for binary traits. The accuracy of major gene and polygene parameter estimates was also very low for binary data compared with those for categorical data; the later gave results similar to normal data. When disease incidence (on binary scale) is close to 50%, segregation analysis has more accuracy and lesser bias, compared to diseases with rare incidences. NDL data were always better than categorical data. Under the MLLM method, the test statistics for categorical and binary data were consistently unusually very high (while the opposite is expected due to loss of information in categorical data), indicating high false discovery rates of major genes if linear models are applied to categorical traits. With Bayesian segregation analysis, 95% highest probability density regions of major gene variances were checked if they included the value of zero (boundary parameter); by nature of this difference between likelihood and Bayesian approaches, the Bayesian methods are likely to be more reliable for categorical data. The BATM segregation analysis of binary data also showed a significant advantage over MLLM in terms of higher accuracy. Based on the results, threshold models are recommended when the trait distributions are discontinuous. Further, segregation analysis could be used in an initial scan of the data for evidence of major genes before embarking on molecular genome mapping.

The Use of Electrostatic Repulsion-Hydrophilic Interaction Chromatography (ERLIC) for Proteomics Research

  • Ng, Justin Tze-Yang;Hao, Piliang;Sze, Siu Kwan
    • Mass Spectrometry Letters
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    • v.5 no.4
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    • pp.95-103
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    • 2014
  • Characterization and studies of proteome are challenging because biological samples are complex, with a wide dynamic range of abundance. At present the proteins are identified by digestion into peptides, with subsequent identification of the peptides by mass spectrometry (MS). MS is a powerful technique for the purpose, but it cannot identify every peptide in such complex mixtures simultaneously. For accurate analysis and quantification it is important to separate the peptides first by chromatography into fractions of a size that MS can handle. With these less complex fractions, the probability is increased of identifying peptides of low abundance that would otherwise experience ion suppression effects due to the presence of peptides of high abundance. Enrichment for peptides with certain post-translational modifications helps to increase their detection rates as well. Electrostatic repulsion-hydrophilic interaction chromatography (ERLIC) is a mixed-mode chromatographic technique which combines the use of electrostatic repulsion and hydrophilic interaction. This review provides an overview of ERLIC and its various proteomics applications. ERLIC has been demonstrated to have good orthogonality to reverse phase liquid chromatography (RPLC), making it useful as a first dimension in multidimensional liquid chromatography (MDLC) and fractionation of digests in general. Peptides elute in order of their isoelectric points and polarity. ERLIC has also been successfully utilized for the enrichment for phosphopeptides and glycopeptides, facilitating their identification. In addition, it is promising for the study of peptide deamidation. ERLIC performs comparably well or better than established methods for these various applications, and serves as a viable and efficient workflow alternative.

Statistical Verification of Precipitation Forecasts from MM5 for Heavy Snowfall Events in Yeongdong Region (영동대설 사례에 대한 MM5 강수량 모의의 통계적 검증)

  • Lee, Jeong-Soon;Kwon, Tae-Yong;Kim, Deok-Rae
    • Atmosphere
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    • v.16 no.2
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    • pp.125-139
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    • 2006
  • Precipitation forecasts from MM5 have been verified for the period 1989-2001 over Yeongdong region to show a tendency of model forecast. We select 57 events which are related with the heavy snowfall in Yeongdong region. They are classified into three precipitation types; mountain type, cold-coastal type, and warm type. The threat score (TS), the probability of detection (POD), and the false-alarm rate (FAR) are computed for categorical verification and the mean squared error (MSE) is also computed for scalar accuracy measures. In the case of POD, warm, mountain, and cold-coastal precipitation type are 0.71, 0.69, and 0.55 in turn, respectively. In aspect of quantitative verification, mountain and cold-coastal type are relatively well matched between forecasts and observations, while for warm type MM5 tends to overestimate precipitation. There are 12 events for the POD below 0.2, mountain, cold-coastal, warm type are 2, 7, 3 events, respectively. Most of their precipitation are distributed over the East Sea nearby Yeongdong region. These events are also shown when there are no or very weak easterlies in the lower troposphere. Even in the case that we use high resolution sea surface temperature (about 18 km) for the boundary condition, there are not much changes in the wind direction to compare that with low resolution sea surface temperature (about 100 km).

Simplified PAR Reduction Technique for MIMO-OFDM System (MIMO-OFDM 시스템에서 간략화된 PAR 감쇄 기법)

  • Song Hyoung-Kyu;Kook Hyung-Joon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.12C
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    • pp.1181-1185
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    • 2005
  • A combining of MIMO signal processing with OFDM is regarded as a promising solution of enhancing the performance of next generation wireless system. Therefore, in this paper, an OFDM-based wireless system employing layered space-time architecture is considered for a high-rate transmission. In the MIMO-OFDM system, we evaluate the PAR performance using the SLM approaches. The investigated SLM scheme for MIMO-OFDM signals selects the transmitted sequence with lowest average PAR over all transmitting antennas and retrieves the side information very accurately at the expense of a slight degradation of the PAR performance. The low probability of false side information can improve the overall detection performance of the MIMO-OFDM system with erroneous side information compared to the ordinary SLM approache, respectively. Also, we provide closed form of the average BER performance in MIMO-OFDM system using analytic approach.

An Uniform Routing Mechanism with Low Energy Consumption over Wireless Sensor Network (유비쿼터스 센서네트워크에서 균일한 에너지 소모를 유도하는 경로설정기법)

  • Yoon Mi-Youn;Lee Kwang-Kyun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.2B
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    • pp.80-90
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    • 2006
  • WSN(Wireless Sensor Network) performs to detect and collect environmental information for one purpose. As examples, WSN is applicable for home network, patient management of a hospital, logistics management, status detection during the war and so on. The WSN is composed of a sink node and several sensor nodes and has a constraint in an aspect of energy consumption caused by limited battery resource. So many required mechanisms in WSN should consider the remained energy condition. A routing mechanism is requested to deliver the collected information to a sink considering energy efficiency in WSN. There have been many researches to establish (a) route(s) for data delivery to the sink. In this paper, we propose establishment of efficient routes. We proposed a uniform routing mechanism together with considering energy efficiency. For the routing, we define energy probability as routing metrics information and Performs suppression of exchange of control messages. In addition, we derive to uniformly consume the energy of the sensor node when establishing the routes. Also, we evaluate and analyze the energy efficiency for proposed mechanisms through NS-2 simulator.

Feasibility Study on the Utilization of EMAT Technology for In-line Inspection of Gas Pipeline

  • Cho, Sung-Ho;Yoo, Hui-Ryong;Rho, Yong-Woo;Kim, Hak-Joon;Kim, Dae-Kwang;Song, Sung-Jin;Park, Gwan-Soo
    • Journal of Magnetics
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    • v.16 no.1
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    • pp.36-41
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    • 2011
  • If gas is leaking out of gas pipelines, it could cause a huge explosion. Accordingly, it is important to ensure the integrity of gas pipelines. Traditionally, over the years, gas-operating companies have used the ILI system, which is based on axial magnetic flux leakage (MFL), to inspect the gas pipelines. Relatively, there is a low probability of detection (POD) for the axial defects with the axial MFL-based ILI. To prevent the buried pipeline from corrosion, it requires a protective coating. In addition to the potential damage to the coating by environmental factors and external forces, there could be defects on the damaged coating area. Thus, it is essential that nondestructive evaluation methods for detecting axial defects (axial cracks, axial groove) and damaged coating be developed. In this study, an electromagnetic acoustic transducer (EMAT) sensor was designed and fabricated for detecting axial defects and coating disbondment. In order to validate the performances of the developed EMAT sensor, experiments were performed with specimens from axial cracks, axial grooves, and coating disbondment. The experimental results showed that the developed EMAT sensor could detect not only the axial cracks (minimum 5% depth of wall thickness) and axial grooves (minimum 10% depth of wall thickness), but also the coating disbondment.

Comparison of diagnostic and treatment guidelines for undescended testis

  • Shin, Jaeho;Jeon, Ga Won
    • Clinical and Experimental Pediatrics
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    • v.63 no.11
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    • pp.415-421
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    • 2020
  • Cryptorchidism or undescended testis is the single most common genitourinary disease in male neonates. In most cases, the testes will descend spontaneously by 3 months of age. If the testes do not descend by 6 months of age, the probability of spontaneous descent thereafter is low. About 1%-2% of boys older than 6 months have undescended testes after their early postnatal descent. In some cases, a testis vanishes in the abdomen or reascends after birth which was present in the scrotum at birth. An inguinal undescended testis is sometimes mistaken for an inguinal hernia. A surgical specialist referral is recommended if descent does not occur by 6 months, undescended testis is newly diagnosed after 6 months of age, or testicular torsion is suspected. International guidelines do not recommend ultrasonography or other diagnostic imaging because they cannot add diagnostic accuracy or change treatment. Routine hormonal therapy is not recommended for undescended testis due to a lack of evidence. Orchiopexy is recommended between 6 and 18 months at the latest to protect the fertility potential and decrease the risk of malignant changes. Patients with unilateral undescended testis have an infertility rate of up to 10%. This rate is even higher in patients with bilateral undescended testes, with intra-abdominal undescended testis, or who underwent delayed orchiopexy. Patients with undescended testis have a threefold increased risk of testicular cancer later in life compared to the general population. Self-examination after puberty is recommended to facilitate early cancer detection. A timely referral to a surgical specialist and timely surgical correction are the most important factors for decreasing infertility and testicular cancer rates.

A Study on Drug trading countermeasures via internet and sns (인터넷과 sns를 이용한 마약거래 대응방안에 관한 연구)

  • Park, Ho Jeong
    • Convergence Security Journal
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    • v.18 no.1
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    • pp.93-102
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    • 2018
  • The drug trade among the general public via the Internet and sns have been increasing, which is becoming a social problem. The general public believe that even if they do the drug trade via the Internet and sns the probability of detection is low. so they will conduct drug trade via the Internet and sns. Therefore, if the general public recognize that there is a high likelihood of disclosure, drug trade via the Internet and sns are likely to decline. If the possibility of punishment increases through specification of controlled delivery techniques and Introduction of entrapment investigator, it seems that the general public can not easily deal with drug trade via the Internet and sns. Also by further subdividing the penalties for drug offenses, for simple drug buyers through cure-oriented treatment rather than punishment drug demand be suppressed and penalties for drug suppliers should be strengthened.

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Evil-Twin Detection Scheme Using SVM with Multi-Factors (다중 요소를 가지는 SVM을 이용한 이블 트윈 탐지 방법)

  • Kang, SungBae;Nyang, DaeHun;Lee, KyungHee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.2
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    • pp.334-348
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    • 2015
  • Widespread use of smart devices accompanies increase of use of access point (AP), which enables the connection to the wireless network. If the appropriate security is not served when a user tries to connect the wireless network through an AP, various security problems can arise due to the rogue APs. In this paper, we are going to examine the threat by evil-twin, which is a kind of rogue APs. Most of recent researches for detecting rogue APs utilize the measured time difference, such as round trip time (RTT), between the evil-twin and authorized APs. These methods, however, suffer from the low detection rate in the network congestion. Due to these reasons, in this paper, we suggest a new factor, packet inter-arrival time (PIAT), in order to detect evil-twins. By using both RTT and PIAT as the learning factors for the support vector machine (SVM), we determine the non-linear metric to classify evil-twins and authorized APs. As a result, we can detect evil-twins with the probability of up to 96.5% and at least 89.75% even when the network is congested.