• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권6호
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• pp.2534-2553
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• 2018

Source routing is the routing scheme that arranges the whole path from source to target at the origin node that may suit the requirements from the upper layer applications' perspective. The centralized control in SDN (Software-Defined Networking) networks enables the awareness of the global topology at the controller. Therefore, augmented source routing schemes can be designed to achieve various purposes. This paper proposes a source routing scheme that conducts the top-K QoS-aware paths discovery in SDN. First, the novel non-invasive QoS over LLDP scheme is designed to collect QoS information based on LLDP in a piggyback fashion. Then, variations of the KSP (K Shortest Paths) algorithm are derived to find the unconstrained/constrained top-K ranked paths with regard to individual/overall path costs, reflecting the Quality of Service. The experiment results show that the proposed scheme can efficiently collect the QoS information and find the top-K paths. Also, the performance of our scheme is applicable in QoS-sensitive application scenarios compared with previous works.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권12호
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• pp.5150-5169
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• 2015

Mobile Ad hoc NETworks (MANETs) are the best choice when mobility, scalability, and decentralized network infrastructure are needed. Because of critical mission applications of MANETs, network security is the vital requirement. Most routing protocols in MANETs assume that every node in the network is trustworthy. However, due to the open medium, the wide distribution, and the lack of nodes' physical protection, attackers can easily compromise MANETs by inserting misbehaving nodes into the network that make blackhole attacks. Previous research to detect the misbehaving nodes in MANETs used the overhearing methods, or additional ACKnowledgement (ACK) packets to confirm the reception of data packets. In this paper a special lightweight acknowledgement-based method is developed that, contrary to existing methods, it uses ACK packets of MAC layer instead of adding new ACK packets to the network layer for confirmations. In fact, this novel method, named PIGACK, uses ACK packets of MAC 802.11 to piggyback confirmations from a receiver to a sender in the same transmission duration that the sender sends a data packet to the receiver. Analytical and simulation results show that the proposed method considerably decreases the network overhead and increases the packet delivery ratio compared to the well-known method (2ACK).

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.313-316
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• 2004

This paper presents a new dynamically adaptable polling scheme for efficient support of real-time traffic over an IEEE 802.11 wireless LAN network. The poll scheduling plays an important role in IEEE 802.11 PCF. However, the current version of the polling list management scheme proposed in the IEEE802.11 standard is inefficient when a variable number of mobile stations have variable packets to transmit. If Point Coordinator(PC) has an exact information on the station status, it is possible to efficiently perform polling. In this thesis. we suggest an adaptable polling scheme to meet requirements of the stations. In our scheme, each station transmits packets including a piggyback information to inform that it wants to receive a poll in the next polling duration. Simulation results indicate that our scheme may reduces the packet discard ratio and real-time packet transfer delay.

• International Journal of Industrial Entomology and Biomaterials
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• 제31권2호
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• pp.85-89
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• 2015

This peptide has antibacterial activity against several Gram-positive and Gram-negative bacteria. Bombyx mori cecropinB1(BmCecB1) is antimicrobial peptides from Bombyx mori and belongs to cecropin family. Antimicrobial peptides are important components of the innate immune systems in all living organism. To produce the BmCecB1 antimicrobial peptide, we constructed transgenic silkworm that expressed BmCecB1 gene under the control BmA3 promoter using piggyBac vector. The use of the 3xP3-driven EGFP cDNA as a marker allowed us to rapidly distinguish transgenic silkworm. Mixtures of the donor vector and helper vector were micro-injected into 600 eggs of bivoltin silkworms, Baegokjam. In total, 49 larvae (G0) were hatched and allowed to develop into moths. The resulting G1 generation consisted of 22 broods, and we selected 2 broods containing at least 1 EGFP-positive embryo. The rate of successful transgenesis for the G1 broods was 9%. We identified 9 EGFP-positive G1 moths and these were backcrossed with wild-type moths. With the aim of identifying a BmCecB1 as antimicrobial peptide, we investigated the Radical diffusion Assay (RDA) and then demonstrated that BmCecB1 possesses high antibacterial activities against Gram-negative bacteria.

• 한국사회복지학
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• 제68권4호
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• pp.25-51
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• 2016

본 연구의 목적은 사회적기업에서 근무하는 결혼이주여성의 근무경험을 탐색해보는 것이다. 이를 위해 C시 사회적기업에서 근무하는 10명의 결혼이주여성들을 심층면담하고, 근거이론 연구방법에 따라 분석하여 113개의 개념, 28개의 하위범주, 13개의 범주를 도출하였다. 분석결과 중심현상은 '존재의 부활'이었고, 핵심 범주는 '사회적기업이라는 제도적 기회와의 조우를 통해 존재의 부활을 경험하고 한국인으로서 자기의 존재를 확장시키기'이었다. 또한 사회적기업에서 근무하는 결혼이주여성의 근무경험은 편승형, 자기확장형, 동반성장형으로 분류되었으며, 상황모형이 제시되었다. 이러한 결과를 바탕으로 결혼이주여성의 사회적기업 취업과 관련된 정책적, 실천적 방안을 제시하였다.

• 천문학회보
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• 제42권1호
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• pp.34.2-34.2
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• 2017

A small wide-field imaging telescope is a powerful instrument to survey the Universe: wide-field image can monitor the variability of many sources at a time, e.g. young stellar objects and active galactic nuclei, and it can be an effective way to locate transient sources without precise positional information such as gravitational wave sources or some gamma-ray bursts. In February 2017, we installed a 0.25 m f/3.6 telescope on the McDonald 0.8 m telescope as a piggyback system. With a $4k{\times}4k$ CCD camera, the telescope has a $2.35{\times}2.35deg$ field-of-view. Currently, it is equipped with Johnson UBVRI filters and 3 narrow-band filters: $H{\alpha}$, OIII and SII. We will present the installation process, and the telescope performance such as detection limit and image quality based on the data from commissioning observations. We will also discuss possible scientific projects with this system.

• 천문학회보
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• 제43권1호
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• pp.69.4-70
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• 2018

KAOS30 is an automatic observing software for the wide-field 10-inch telescope as a piggyback system on the 30-inch telescope at the McDonald Observatory in Texas, US. The software has four packages in terms of functionality and is divided into communication with Telescope Control System (TCS), controlling of CCD camera and filter wheel, controlling of focuser, and script for automation observing. Each interconnect of those are based on exe-exe communication. The advantage of this distinction is that each package can be independently maintained for further updates. KAOS30 has an integrated control library that combines function library connecting each device and package. This ensures that the software can extensible interface because all packages are access to the control devices independently. Also, the library includes the ASCOM driver platform. ASCOM is a standard general purpose library that supports Application Programming Interface (API) of astronomical devices. We present the software architecture of KAOS30, and structure of interfacing between hardware and package or package and package.

• 한국정보과학회논문지:정보통신
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• 제30권2호
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• pp.143-154
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• 2003

분산 이동 시스템은 단순한 통신 기능에서 작업 흐름 관리, 화상회의, 복제 데이터의 관리, 자원 할당 둥의 서비스를 제공하는 시스템으로 급속히 확대.발전하고 있으며, 이러한 서비스를 제공하는 어플리케이션들은 사용자의 요구를 반영하기 위해 메시지를 인과적 순서로 전달해야 한다. 인과적 메시지 전달을 제공하는 기존의 방법들은 많은 피기백(piggyback) 정보로 인한 통신 오버헤드 혹은 어플리케이션으로 전달하는 메시지의 지연, 이동 호스트의 증가에 대한 확장성, 이동 호스트가 계산의 대부분을 수행하는 둥의 문제점이 있다. 이 논문은 기지국과 이동 호스트 사이의 종속 정보 행렬을 기지국이 유지하며, 즉각 선행자 메시지(immediate predecessor message)에 대한 종속 정보만을 각 메시지에 피기백 하는 방법을 통해 기존 기법의 문제점을 해결하는 효율적인 인과적 메시지 전달 기법을 제안한다. 제안하는 알고리즘은 이전의 알고리즘들과 비교해서 낮은 메시지 오버헤드를 가지며, 메시지를 전달할 때 불필요한 지연(inhibition)을 발생시키지 않는다. 또한 기지국에서 알고리즘의 대부분을 수행하도록 함으로써 이동 호스트의 자원제약과 무선 통신의 낮은 대역폭을 고려하고, 이동 호스트 단위로 인과적 메시지 전달을 이행함으로써 발생하는 처리 지연(processing delay)을 줄여준다.

• 대한전자공학회논문지SD
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• 제37권8호
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• pp.1-8
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• 2000

0.3 g의 하드디스크 드라이브에 사용될 수 있는 마그네틱 헤드를 장착할 수 있는 트랙 추적용 마이크로 액추에이터를 제작하였다. 이 액추에이터는 정전방식을 적용하였으며 2${\mu}m$ 두께의 열산화막과 20${\mu}m$ 두께의 실리콘 막이 직접접합된 SOI 웨이퍼를 이용하여 단지 3장의 마스크만을 사용하여 제작하였다. 고유진동수는 18.5 kHz이고 15 V DC와 15 V AC 전압이 동시에 가해진 상황에서 그 변위가 1.4 ${\mu}m$이였고 이때 30 V일 때 50 N의 정전력을 나타내었다. 또한 2.21 kHz의 서보 주파수 대역에서 이득여유가 7.51 dB이고 위상여유가 50.98$^{\circ}$이였다. 따라서 이 트랙추적 마이크로 액추에이터는 10 Gb/in$^2$의 기록밀도를 요구하는 하드디스크 드라이브에 충분히 이용될 수 있을 것이다.

• 한국가금학회지
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• 제42권3호
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• pp.239-245
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• 2015

Transgenic animals have been widely used for developmental biology studies, as disease models, and even in industry such as transgenic bioreactor animals. For transgenic birds, quail has the great advantages of small body size, short generation time, and frequent egg production. To date, retroviral or lentiviral transduction has been used to generate transgenic quail for various purposes. However, the efficiency of transgenic offspring production with these methods is relatively low and viral vector usage has safety issues. Unfortunately, non-viral transgenesis has not been established in quail due to a deficiency of stem cell and germ cell culture systems. In this study, we established a direct in ovo lipofection method that could be used to create transgenic quail without germline-competent cells or viruses. To optimize the injection stage during embryo development, the liposome complex (containing piggyBacCMV-GFP and transposase plasmids) was introduced into an embryonic blood vessel at 50 hr, 55 hr or 60 hr. GFP expression was detected in various tissues (heart, kidney, liver and stomach) on day 12 of incubation under a fluorescence microscope. Additionally, GFP-positive cells were detected in the recipient embryonic gonads. In conclusion, the direct in ovo lipofection method with the piggyBac transposon could be an efficient and useful tool for generating transgenic quail.