• Title/Summary/Keyword: NTP

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A Study on System for Synchronization of Multiple UAVs and Ground Control System (무인이동체 및 지상국 컴퓨터 간의 시간 정보 동기화를 위한 시스템 연구)

  • Lee, Won-Seok;Lee, Woon-Sang;Song, Hyoung-Kyu
    • Journal of the Semiconductor & Display Technology
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    • v.19 no.1
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    • pp.11-16
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    • 2020
  • In this paper, system that includes multiple unmanned aerial vehicles (UAVs) are considered. The vehicles are equipped with a mission computer for a specific mission and equipment. The mission equipment operates based on the time of mission computer. Also, data collected by flight computer and mission computer is saved with the time of each operating system. Generally, time offset between multiple computers always exists, though the computers are connected to the Internet. When the data collected by multiple computers is combined, the time offset causes damage on reliability of the combined data. Computers that connected to the Internet are synchronized by network time protocol (NTP). This paper proposes a system that the time of multiple mission computers are synchronized by the same NTP server to minimize the time offset. In the results of the measurement, the system time offset of multiple mission computer is maintained within 10ms from the system time of the server computer.

Anti-inflammatory effect of non-thermal atmospheric pressure plasma for periodontitis treatment: in vitro pilot study (치주염 치료를 위한 저온상압 플라즈마의 항염효과: 예비 실험)

  • Park, You li;Kim, Hyun-Joo;Lee, Ju-Youn;Jeong, Sung-Hee;Kwon, Eun-Young;Joo, Ji-Young
    • Journal of Dental Rehabilitation and Applied Science
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    • v.37 no.2
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    • pp.88-94
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    • 2021
  • Purpose: The purpose of this study was to evaluate the anti-inflammatory effects of non-thermal atmospheric pressure plasma (NTP) on human gingival fibroblasts (HGFs) for clinical application of periodontal treatment. Materials and Methods: HGFs were treated with Porphyromonas gingivalis (Pg) lipopolysaccharide (LPS). Customized NTP device was developed for periodontal in vitro study. Cell viability was evaluated with cell counting kit-8. The levels of inflammatory cytokines, including interleukin (IL)-8 and 6, were determined by enzyme-linked immunosorbent assay. Results: When NTP was applied, the cell viability did not change significantly, and there was no difference for 6 h and 24h. When Pg LPS was treated to HGFs, the secretion of IL-8 and IL-6 was increased compared to the control group. But when the NTP was applied, the secretion of them was significantly decreased. Conclusion: NTP did not affect cell viability of HGFs. And it inhibited the LPS-induced production of IL-8 and IL-6.

The Development of Protocol for Construction of Smart Factory (스마트 팩토리 구축을 위한 프로토콜 개발)

  • Lee, Yong-Min;Lee, Won-Bog;Lee, Seung-Ho
    • Journal of IKEEE
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    • v.23 no.3
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    • pp.1096-1099
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    • 2019
  • In this paper, we propose the protocol for construction of smart factory. The proposed protocol for construction of smart factory consists of an OPC UA Server/Client, a technology of TSN realtime communication, a NTP & PTP time synchronization protocol, a FieldBus protocol and conversion module, a technology of saving data for data transmit latency and synchronization protocol. OPC UA server/client is a system integration protocol which makes interface industrial hardware device and supports standardization which allows in all around area and also in not independent from any platform. A technology of TSN realtime communication provides an high sensitive time management and control technology in a way of sharing specific time between devices in the field of high speed network. NTP & PTP time synchronization protocol supports IEEE1588 standardization. A fieldbus protocol and conversion module provide an extendable connectivity by converting industrial protocol to OPC. A technology of saving data for data transmit latency and synchronization protocol provide a resolution function for a loss and latency of data. Results from testing agencies to assess the performance of proposed protocol for construction of smart factory, response time was 0.1367ms, synchronization time was 0.404ms, quantity of concurrent access was 100ea, quantity of interacting protocol was 5ea, data saving and synchronization was 1,000 nodes. It produced the same result as the world's highest level.

Quality Properties and Carotenoid Pigments of Yellow Sweet Potato Puree (황색고구마 퓨레의 품질과 Carotenoid색소)

  • 정순택;임종환;강성국
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.4
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    • pp.596-602
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    • 1998
  • Two kinds of sweet potato puree were prepared with Benihayato cultivar of yellow sweet potato with or without $\alpha$-amylase enzyme treatment. Chemical and rheological properties of enzyme-treated puree were different from those of control puree. Reducing sugar content and iodine value increased by $\alpha$-amylase enzyme treatment, while alcohol insoluble solids and viscosity decreased by enzyme treatment. However, the changes of carotenoid content were not significantly different. Hunter-b-values(yellowness) were 27.19 and 23.54 for no enzyme-treated puree(NTP) and enzyme-treated puree(ETP), respectively. Hunter-a values(redness) were 2.24 and 6.05 for NTP abd ETP, respectively. Content of total carotenoid of canned puree heated at 13$0^{\circ}C$ for 30 min decreased by 59 percents.

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A Study on the Characteristic of Ozone and $NO_x$ Generation in the Electerostatic Precipitators (정전식 집진기에서 오존, $NO_x$ 발생특성에 관한 연구)

  • Noh, Kwang-Chul;Lee, Young-Ho;Oh, Myung-Do
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1423-1428
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    • 2003
  • We investigated the amount of the toxic gases emitted from the Electrostatic Precipitators(ESPs), which were currently used by indoor air cleaners. We used the wire-to-plate(WTP) type and the needle-to-plate(NTP) type corona discharger in our study. Using the voltage, the polarity of wire, the number of needles of NTP as the input variables, we studied the characteristic of Ozone and $NO_x$ generation in the ESPs. As the results, we found out that the concentration of Ozone, $NO_2$ and $NO_x$ is increased, but the amount of NO is decreased with increasing the voltage and the number of needles. And we knew that the generation rate of ozone and $NO_x$ is very related with the corona region.

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Implementation of Node Transition Probability based Routing Algorithm for MANET and Performance Analysis using Different Mobility Models

  • Radha, Sankararajan;Shanmugavel, Sethu
    • Journal of Communications and Networks
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    • v.5 no.3
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    • pp.202-214
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    • 2003
  • The central challenge in the design of ad-hoc networks is the development of dynamic routing protocol that efficiently finds route between mobile nodes. Several routing protocols such as DSR, AODV and DSDV have been proposed in the literature to facilitate communication in such dynamically changing network topology. In this paper, a Node Transition Probability (NTP) based routing algorithm, which determines stable routes using the received power from all other neighboring nodes is proposed. NTP based routing algorithm is designed and implemented using Global Mobile Simulator (GloMoSim), a scalable network simulator. The performance of this routing algorithm is studied for various mobility models and throughput, control overhead, average end-to-end delay, and percentage of packet dropped are compared with the existing routing protocols. This algorithm shows acceptable performance under all mobility conditions. The results show that this algorithm maximizes the bandwidth utilization during heavy traffic with lesser overhead.

Time Management System for Applications of UAV Network

  • Lee, Won-Seok;Jang, Jun-Yong;Song, Hyoung-Kyu
    • Journal of Positioning, Navigation, and Timing
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    • v.9 no.4
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    • pp.405-409
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    • 2020
  • This paper proposes time management system for unmanned aerial vehicle (UAV) network. The computers of the UAVs need time synchronization that time offset does not exceed the minimum interval of data samples for errorless data blending between the computers. The proposed time management system is composed of time synchronization and general management systems for UAV control. The systems communicate each other for time information and control signals. The synchronization system uses improved version of existing time offset estimation that network time protocol (NTP) uses. The time synchronization is operated when the time offset of any UAV exceeds threshold that preconfigured by the general management system. The demonstration of prototype shows stable time synchronization satisfying preconfigured threshold.

NMR Studies on the N-terminal Acetylation Domain of Histone H4

  • Bang, Eun Jeong;Lee, Chang Hun;Yun, Jong Bok;Cheong, Ju Hui;Lee, Dae Yun;Lee, Won Tae
    • Bulletin of the Korean Chemical Society
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    • v.22 no.5
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    • pp.507-513
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    • 2001
  • Histones, nuclear proteins that interact with DNA to form nucleosomes, are essential for both the regulation of transcription and the packaging of DNA within chromosomes. The N-terminal domain of histone H4 which contains four acetylation sites at lysines, may play a separate role in chromatin structure from the remainder of the H4 chain. NMR data suggest that H4NTP peptide does have relating disordered structure at physiological pH, however, it has a defined structure at lower pH conditions. The solution structure calculated from NMR data shows a well structured region comprising residues of Val21-Asp24. In addition, our results suggest that the H4NTP prefers an extended backbone conformation at acetylation sites, however, it (especially Lys 12 ) became more defined structures after acetylation for its optimum function.

Clinical Considerations of the Surgical Treatments of the Pressure Sore (욕창의 수술적 치료에 대한 임상적 고찰)

  • Lee, Keun Cheol;Moon, Joo Bong;Kwon, Yong Seok;Cha, Byung Hoon;Kim, Seok Kwun
    • Archives of Plastic Surgery
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    • v.34 no.5
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    • pp.574-579
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    • 2007
  • Purpose: The number of sore patients are increasing steadily, especially in old ages, chronic disease and paralytic patients. Most of patients need to surgical treatment. The aim of this paper is to assess clinical analysis of surgical treatment and to consider operative methods, complications, and recurrences.Methods: We reviewed the data from 82 consecutive patients with 101 pressure sores from March 2003 to May 2006 to discuss the occurrence rate and recurrence rate according to the site on the basis of the presence or absence of paraplegic and its etiology-the patients were categorized into three diagnostic groups: traumatic paraplegics(TP), nontraumatic paraplegics (NTP), and nontraumatic nonparaplegics(NTNP). We examined the sites and sizes of each lesions, patient's state, primary causes of pressure sore, operative methods as each sites and groups, occurrence of complications and recurrences on each groups. Results: In 82 patients, 52 patients were male, 30 patients were female. The male to female ratio was 1.7 :1. Mean age was 55.8 years. 27 patients were in TP group, 35 in NTP group, and 20 in NTNP group, respectively. The common site of sore were sacral area (50.5%), greater trochanteric area(15.8%) and ischial area(13.9%). In each group, incidence rate of recurrence and complication were 11.1%, 40.7% in TP, 5.7%, 5.7% in NTP and 15%, 45% in NTNP. Conclusion: Surgeons must consider the general condition of the patient and possibility of recurrence and returning of daily life. We propose that cutaneous flap, fasciocutaneous flap or skin graft as well as musculocutaneous flap be useful to repair of sore site as each patient's state.