• Title/Summary/Keyword: method of research

Search Result 66,515, Processing Time 0.082 seconds

New X-Y Channel Driving Method for LED Backlight System in LCD TVs

  • Cho, Dae-Youn;Oh, Won-Sik;Cho, Kyu-Min;Moon, Gun-Woo
    • Proceedings of the KIPE Conference
    • /
    • 2007.07a
    • /
    • pp.334-336
    • /
    • 2007
  • This paper proposes a novel RGB-LED (light emitting diode) backlight system, for 32" LCD TVs, accompanied by a new X-Y Channel drive method in which its row and column switches control the individual division screen. This proposed driving method is able to produce division drive effects such as image improvement and reduced power consumption. Not only that, the number of converter needed in this method, that is 1 with $4^*$(m+n) switches, is much fewer than that of cluster drive method, that is $4^*(m^*n)$.

  • PDF

Anomaly Detection Method for Drone Navigation System Based on Deep Neural Network

  • Seo, Seong-Hun;Jung, Hoon
    • Journal of Positioning, Navigation, and Timing
    • /
    • v.11 no.2
    • /
    • pp.109-117
    • /
    • 2022
  • This paper proposes a method for detecting flight anomalies of drones through the difference between the command of flight controller (FC) and the navigation solution. If the drones make a flight normally, control errors generated by the difference between the desired control command of FC and the navigation solution should converge to zero. However, there is a risk of sudden change or divergence of control errors when the FC control feedback loop preset for the normal flight encounters interferences such as strong winds or navigation sensor abnormalities. In this paper, we propose the method with a deep neural network model that predicts the control error in the normal flight so that the abnormal flight state can be detected. The performance of proposed method was evaluated using the real-world flight data. The results showed that the method effectively detects anomalies in various situation.

Validation of LC-MS/MS Method for Analysis of Paralytic Shellfish Toxins in Shellfish and Tunicates (LC-MS/MS를 이용한 패류 및 피낭류 중 마비성 패류독소 분석법의 유효성 검증)

  • Cho, Sung Rae;Kim, Dong Wook;Yu, Hean Jae;Cho, Seong Hae;Ryu, Ara;Lee, Ka Jeong;Mok, Jong Soo
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.53 no.2
    • /
    • pp.174-180
    • /
    • 2020
  • The mouse bioassay has been used widely for the monitoring of paralytic shellfish toxins (PSTs) in many countries. However, this method shows low sensitivity and high limit of detection (LOD), as well as it cannot confirm toxic profiles. Recently, LC-MS/MS method was studied for the quantitative of PSTs, however, the method has any problems with unstable retention times by ionization suppression caused by high salt concentration in shellfish extracts. To establish an alternative method for PSTs analysis, we tried to original LC-MS/MS methods adding desalting operation using amorphous graphitized polymer carbon solid-phase extraction cartridges. The method validation was conducted to determine linearity, limit of detection, limit of quantification (LOQ), accuracy, and precision in quantifying PSTs. The correlation coefficients for all tested PSTs maintained over 0.999. The LODs and LOQs for all PSTs were about 0.19-1.05 ㎍/kg and 0.58-3.18 ㎍/kg, respectively. The accuracies for PSTs were 95.4-107.7% for saxitoxin group, 97.1-100.9% for gonyautoxin group, 99.0-100.8% for N-sulfocarbamoyl toxin group, and 96.8-104.6% for decarbamoyl toxin group. These results indicate that the modified LC-MS/MS method was appropriate for analyzing the PSTs in shellfish and tunicates.

Comparison of Analytical Methods for the Detection of Paralytic Shellfish Toxins (PSTs) (마비성패류독소 검출을 위한 분석법 비교)

  • Lee, Ka Jeong;Kwon, Soon Jae;Jung, Yeoun Joong;Son, Kwang Tae;Ha, Kwang Soo;Mok, Jong Soo;Kim, Ji Hoe
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.50 no.6
    • /
    • pp.669-674
    • /
    • 2017
  • Paralytic shellfish toxins (PSTs) are produced by marine dinoflagellate phytoplankton Alexandrium spp. and Gymnodinium spp. These toxins accumulate in filter feeding organisms such as bivalves and the ingestion of contaminated shellfish can cause illness in humans. The mouse bioassay (MBA) has been the preferred PST testing method worldwide for more than 50 years. However, this assay has several disadvantages, such as detection limits, non-toxic-profiles, and the ethical issues of using animals. The aim of this study was to establish an alternative to the MBA method for testing for PSTs. We optimized the analysis conditions of a post-column oxidation-high performance liquid chromatography (PCOX-HPLC) method and the Scotia Rapid Test Kit, and then compared the accuracy of these methods to the MBA method. The results demonstrated a strong correlation between the PCOX-HPLC method and the MBA, although the PCOX-HPLC method required expensive equipment and standard material, and was time consuming. The Scotia Rapid Test Kit promises to be a useful tool, as it provided rapid and qualitative results, although the method sometimes gave a false positive result that could not be explained by toxin profiles.

A threshold decision of the object image by using the smart tag

  • Im, Chang-Jun;Kim, Jin-Young;Joung, Kwan-Young;Lee, Ho-Gil
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2005.06a
    • /
    • pp.2368-2372
    • /
    • 2005
  • We proposed a novel method for object recognition using the Smart tag system in the previous research. We identified the object easily, but could not assure the object pose, because the threshold problem was not solved. So we propose a new method to solve this threshold problem. This method uses a smart tag to decide the threshold by recording color information of the image when the object feature is extracted. This method records the original of the object color information at the smart tag first. And then it records the object image information, the circumstance image information and the sensors information continuously when the object feature is extracted through the experiments. Finally, it estimates the current threshold by recorded information. This method can be applied the threshold to each objects. And it can solve the difficult threshold decision problem easily. To approve the possibility of our method, we implemented our approach by using easy and simple techniques as possible.

  • PDF

An Efficient Monitoring Method of a Network Protocol for Downloadable CAS

  • Jeong, Young-Ho;Kwon, Oh-Yung;Ahn, Chung-Hyun;Hong, Jin-Woo
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • 2010.07a
    • /
    • pp.32-35
    • /
    • 2010
  • This paper presents an efficient monitoring method of a network protocol for a downloadable conditional access system (DCAS) that can securely transmit conditional access software via a bi-directional communication channel. In order to guarantee a secure channel based on mutual authentication between a DCAS head end server and set-top boxes, DCAS messages are encrypted and digitally signed. Owing to applied cryptographic algorithms, it is impossible to get information from messages directly without additional processing. Through categorizing DCAS messages into several groups, the proposed monitoring method can efficiently parse and trace DCAS messages in real-time. In order to verify the stability and effectiveness of the proposed monitoring method, we implement a DCAS monitoring system capable of capturing and parsing all DCAS messages. The experimental results show that the proposed monitoring method is well designed.

  • PDF

Review for verification of capacitive current performance by using synthetic testing method (합성시험법을 이용한 진상소전류 성능검증에 관한 고찰)

  • Park, Seung-Jae;Kim, Yong-Sik;Park, Yong-Hwan;Kim, Maeng-Hyun;Koh, Heui-Seog
    • Proceedings of the KIEE Conference
    • /
    • 2006.07a
    • /
    • pp.466-467
    • /
    • 2006
  • Several synthetic testing methods have widely been used for the performance evaluation of ultra high-voltage circuit breaker. Among these synthetic method, in the paper, capacitance switching testing method which can meet the test requirements and increase the testing capacity has been proposed. This method is made up of two separated sources of short-circuit generator for current source and L-C resonance circuit for voltage source. By using this method, KERI will perform the performance evaluation of capacitive current switching performance for the 800kV GCB(Gas Circuit Breaker).

  • PDF

A Solid-Phase Extraction Method for Analyzing Trace Amounts of Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans in Waste Water

  • Park, Deok-Hie;Youn, Yeu-Young;Choi, Jae-Won;Lim, Young-Hee;Cho, Hye-Sung
    • Mass Spectrometry Letters
    • /
    • v.2 no.1
    • /
    • pp.12-15
    • /
    • 2011
  • The Korean government has regulated emission of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in waste water of manufacturing facilities producing chlorinated compounds since 2009. As this regulation is expected to be reinforced in 2013 to 50 pg I-TEQ/L, a large sample volume is required for the analysis of trace amounts of PCDD/Fs in waste water. Liquid-liquid extraction (LLE) is used to extract PCDD/Fs from aqueous samples; however, its low efficiency makes it inadequate for analyzing large sample volumes. Herein, we present a disk-type solid-phase extraction (SPE) method for the analysis of dioxin at a part per quadrillion level in waste water. This SPE system contains airtight glass covers with a decompression pump, which enables continuous semi-automated extraction. Small (0.5 L) and large (7 L) samples were extracted using LLE and SPE methods, respectively. The method detection limits (MDLs) were 0.001.0.25 and 0.015.4.1 pg I-TEQ/L for the SPE and LLE methods, respectively. The concentrations of detected congeners with both methods were similar. However, the concentrations of several congeners that were not detected with the LLE method were quantified using the SPE method.

Qualitative interviewing as a research method: Its philosophical frameworks and practical guidelines (연구 방법으로써의 질적 인터뷰: 철학적 의미와 방법적 측면)

  • Cheon Hyejung
    • Journal of Family Resource Management and Policy Review
    • /
    • v.8 no.3
    • /
    • pp.113-125
    • /
    • 2004
  • This study aims to provide philosophical frameworks and approaches, and practical guidelines to interview research. While there are some studies which focus on the practical guidelines, there is a lack of studies which address the philosophical and conceptual issues integral to qualitative interview research. By discussing three different but related philosophical aspects of qualitative interviewing--phenomenology, hermeneutics, and dialectics--consistency among research purpose, research method, research methodology is pursued. Based on this discussion, four stages of interviewing--designing, conducting, analyzing, and writing of qualitative interview research--are presented.

  • PDF

Research on the Analysis of Maritime Traffic Pattern using Centroid Method (중심점 기법을 이용한 통항패턴 분석에 관한 연구)

  • Kim, Hye-Jin;Oh, Jae-Yong
    • Journal of Navigation and Port Research
    • /
    • v.42 no.6
    • /
    • pp.453-458
    • /
    • 2018
  • The analysis of maritime traffic refers to the processes that are used to analyze the environmental characteristics of the target area and, based on this analysis, predict the traffic pattern of the vessels. In recent years, maritime traffic analysis has become significant with increase maritime traffic volume and expansion of VTS coverage area. In addition, maritime traffic analysis is also applicable in the safety assessment of port facilities and the VTS (Vessel Traffic Service). In this paper, we propose a method to analyze the vessels' traffic pattern by using the heat map and the centroid method. This method is efficient for the analysis of the vessel trajectory data where spatial characteristics change with time. In the experiments, the traffic density and centroid by time have were analyzed. Trajectory data collected at Mokpo harbor was adopted. Finally, we reviewed the experimental results to verify the feasibility of the proposed method as a maritime traffic analysis method.