• Journal of Periodontal and Implant Science
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• v.53 no.6
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• pp.467-477
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• 2023

Purpose: The purpose of this study was to evaluate the regenerative capacity of stem cells combined with bone graft material and a collagen matrix in rabbit calvarial defect models according to the type and form of the scaffolds, which included type I collagen matrix and synthetic bone. Methods: Mesenchymal stem cells (MSCs) were obtained from the periosteum of participants. Four symmetrical 6-mm-diameter circular defects were made in New Zealand white rabbits using a trephine drill. The defects were grafted with (1) group 1: synthetic bone (β-tricalcium phosphate/hydroxyapatite [β-TCP/HA]) and 1×10⁵ MSCs; (2) group 2: collagen matrix and 1×10⁵ MSCs; (3) group 3: β-TCP/HA, collagen matrix covering β-TCP/HA, and 1×10⁵ MSCs; or (4) group 4: β-TCP/HA, chipped collagen matrix mixed with β-TCP/HA, and 1×10⁵ MSCs. Cellular viability and cell migration rates were analyzed. Results: Uneventful healing was achieved in all areas where the defects were made at 4 weeks, and no signs of infection were identified during the healing period or at the time of retrieval. New bone formation was more evident in groups 3 and 4 than in the other groups. A densitometric analysis of the calvarium at 8 weeks post-surgery showed the highest values in group 3. Conclusions: This study showed that the highest regeneration was found when the stem cells were applied to synthetic bone along with a collagen matrix.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2904-2906
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• 2000

본 논문에서는 반도체 제조 공정에서 장비와 호스트간에 통신을 할 수 있는 SECS(SEMI Equipment Communications Standard) 프로토를의 개발을 제안한다. SECS 프로토콜은 메시지 전송을 위한 헤더 부분을 정의하는 SECS-I 프로토콜과 메시지 내용을 정의하는 SECS-II 프로토콜로 나뉘어지는데, RS232 시리얼 통신을 하는 SECS-I 프로토콜 대신에 이더넷(ethernet)을 통해 TCP/IP 통신을 할 수 있는 HSMS 프로토콜을 구현하고자 한다. HSMS(High-speed SECS Message Services)프로토콜은 SECS-I과 마찬가지로 SECS-II 메시지 내용을 전송 할 수 있도록 10바이트 크기의 헤더로 정의된다. HSMS 프로토콜 통신은 TCP/IP를 기반으로 하기 때문에 SECS 메시지 전송을 위한 통신 선로를 설정하기 위해 소켓 API를 응용하고 항상 통신 대기상태를 유지하기 위해 데몬(daemon) 형태로 구성한다. 실제 메시지 내용을 정의하고 있는 SECS-II 프로토콜은 데이터 인덱스 테이블과 표준에 정의된 형식에 맞게 파일형태나 DLL(Dynamic Link Library)형태로 구성하고 프로세스 프로그램(process program)을 수행하기 위해 SECS 프로토콜 표준에서 정의하는 SML(SECS Message Language)형식으로 변환 할 수 있는 스크립트 변환기(script translator)를 구현한다. 또한 HSMS 프로토콜이 전송할 SECS-II 메시지를 저장하기 위한 파라미터를 정의하고 실제 통신을 위한 테스트 베드를 위한 응용 프로그램을 제작한다

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.569-572
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• 2008

I proposed wireless ordering system using Qt embedded. This system will make the good use of real life applications and make fit for practical use. I embodied data input, transfer, gathering and back-transfer on wireless network using TCP/IP protocol on QSocket provided by Qt. Server environment is Linux 9.0 and gcc-2.95.3 on PC, and three target-boards consist PXA255 processor with wireless-LAN card which communicate through wireless access pointer. Software tools on target-board are gcc, tmake, qt-X11, qt-embedded and etc. I designed touch-screen interface for user convenience.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.1
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• pp.36-48
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• 2008

To repair bone defects in the oral and maxillofacial field, bone grafts including autografts, allografts, and artificial bone are used in clinical dentistry despite several disadvantages. The purpose of this study was to evaluate new bone formation and healing in rat calvarial bone defects using hydroxyapatite (HA, $Ca_{10}[PO_4]_6[OH]_2,\;Bongros^{(R)}$, Bio@ Co., KOREA) and tricalcium phosphate (${\beta}-TCP,\;Ca_3[PO_4]_2$, Sigma-Aldrich Co., USA) mixed at various ratios. Additionally, this study evaluated the effects of type I collagen (Rat tail, BD Biosciences Co., Sweden) as a basement membrane organic matrix. A total of twenty, 8-week-old, male Sprague-Dawley rats, weighing 250-300g, were divided equally into a control group (n=2) and nine experimental groups (n=2, each). Bilateral, standardized transosseous circular calvarial defects, 5.0 mm in diameter, were created. In each experimental group, the defect was filled with HA and TCP at a ratio of 100:0, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80, and 0:100 with or without type I collagen. Rats were sacrificed 4 and 8 weeks post-operation for radiographic (standardized plain film, Kodak Co., USA), histomorphologic (H&E [Hematoxylin and Eosin], MT [Masson Trichrome]), immunohistochemical staining (for BMP-2, -4, VEGF, and vWF), and elementary analysis (Atomic absorption spectrophotometer, Perkin Elmer AAnalyst $100^{(R)}$). As the HA proportion increased, denser radiopacity was seen in most groups at 4 and 8 weeks. In general radiopacity in type I collagen groups was greater than the non-collagen groups, especially in the 100% HA group at 8 weeks. No new bone formation was seen in calvarial defects in any group at 4 weeks. Bridging bone formation from the defect margin was marked at 8 weeks in most type I collagen groups. Although immunohistochemical findings with BMP-2, -4, and VEGF were not significantly different, marked vWF immunoreactivity was present. vWF staining was especially strong in endothelial cells in newly formed bone margins in the 100:0, 80:20, and 70:30 ratio type I collagen groups at 8 weeks. The calcium compositions from the elementary analysis were not statistically significant. Many types of artificial bone have been used as bone graft materials, but most of them can only be applied as an inorganic material. This study confirmed improved bony regeneration by adding organic type I collagen to inorganic HA and TCP mixtures. Therefore, these new artificial bone graft materials, which are under strict storage and distribution systems, will be suggested to be available to clinical dentistry demands.

• Journal of Korea Multimedia Society
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• v.10 no.1
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• pp.74-82
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• 2007

IPv6 is the internet protocol for next generation which can solve the problem of IPv4 protocol. Mobile IPv6 efficiently provides the mobility for mobile devices holding the properties of IPv6. iSCSI(Internet Small Computer System Interface) is a block-oriented storage access protocol that enables a user to recognize a remote storage as their own local block device through general TCP/IP networks. Since iSCSI uses a standard Ethernet switch and router for this kind of access, it can not only be applized to Ethernet technologies, but can also be used to create a storage networking system without any distance restrictions that can equally be applied to a wireless network environment. Accordingly, this paper presents an alternative approach to overcome the limited storage space of mobile devices based on the IPv6 iSCSI initiator driver which was originally designed for wired networks. Also, this paper describes about the implementation and performance analysis of mobile education service system using virtual storage devices in IPv6 wireless networks.

• The Journal of the Korea Contents Association
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• v.10 no.8
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• pp.73-83
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• 2010

This paper investigates protocol architecture of a Web-ZigBee gateway for interconnecting TCP/IP-based networks and ZigBee/IEEE802.15.4-based wireless sensor networks. The Web-ZigBee gateway delivers data between the TCP/IP network and the ZigBee network. Since those two networks have different communication protocols, a protocol translation mechanism is needed. Herein, we propose a method to deliver query messages from the Internet to the sensor network and receive data from sensors. The protocol translation is performed in the translation layer that is placed above the two application layers, i.e., the Internet application layer and ZigBee application layer. Among various interfaces, we use CGI programming to take care of translation functions efficiently. The CGI manages query information from a client on the Internet and data from the ZigBee sensor network. Whereas the TCP/IP enabled sensor network overlays two heterogeneous communication protocols, overlaying layers increase the complexity and cost of implementing the sensor network. On the contrary, the sensors in our gateway-based system are not only light (because each communication protocol works independently without overlaying), but also efficient because the translation layer mostly alleviates header overloading.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.2
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• pp.102-110
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• 2006

This paper explains the design and development of the stand-alone high sound quality Internet Radio system, which is aimed for a small embedded type audio device rather than a general PC type. This device is designed to work with an Internet connection. This kind of system is not standardized so far, and also the related algorithm is not open to the public. So it is necessary to analyze several receiving algorithms of current radio receivers, and develop our own hardware in order to overcome these obstacles, finally to get the high quality of sound radio. The main electronic components of this Internet Radio are TCP/IP interfaces, an audio MP3 decoder, an I/O interface, and a Flash Memory Card with advanced audio multicasting for the next-generation Internet Radio. Basic structures and implementation issues of the next-generation most-versatile digital music player, and Internet Radio receivers, are discussed.

• 한국정보통신설비학회:학술대회논문집
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• 2004.08a
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• pp.137-141
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• 2004

네트워크 사용자의 급속한 증가로 네트워크 내의 부하를 감당하기에는 많은 어려움을 가져왔다. 이와 같은 이유로 기존의 TCP/IP에서 세션을 통하여 노드들 간의 통신을 연결하는 방식에서 현재는 하나의 채널을 통해 고속의 I/O가 가능하도록 하는 기술이 많이 연구되고 있다. 그 대표적인 것으로 인피니밴드가 있다. 인피니밴드는 프로세싱 노드와 입출력 장치 사이의 통신, 프로세스간 통신에 대한 산업 표준이 되고 있고 프로세싱 노드와 입출력 장치를 연결하기 위해 스위치 기반의 상호 연결은 전통적인 버스 입출력을 대체하는 새로운 입출력 방식이 사용된다. 또한 인피니밴드에서는 현재 많은 이슈가 되고 있는 RDMA 방식을 이용해 원격지 서버들 간에 직접 메모리 접근 방식을 통해 CPU와 OS의 로드를 최소화하고 있다. 본 논문에서는 RDMA를 적용한 새로운 채널 기반 네트웍의 프로토콜인 SDP(Socket Direct Protocol)를 구현하여 SDP_STREAM의 패킷 처리량에 대한 성능을 평가한다. 그리고 이에 대한 성능 평가를 위해서 Netperf 툴을 이용했다. 특히 Zero-Copy방식을 사용하지 않는 일반적인 소켓 API을 이용한 TCP_STREAM과 Zero-Copy방식을 이용한 SDP_STREAM의 패킷 처리량을 비교했으며 성능 평가 결과는 기존의 TCP_STREAM 패킷 처리량에 비해 약 3배 이상 향상된 결과를 나타냈다.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.7
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• pp.694-702
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• 2007

The SSWM(Software Switching Mechanism) of I-processor concept using non-real time in-house software simulation program is an effective method in order to develop the flight control law in desktop or HQS environment. And, this system has some advantages compare to HSWM(Hardware Switching Mechanism) such as remove the time delay effectiveness and reduce the costs of development. But, if this system loading to the OFP(Operational Flight Program), the OFP guarantee the enough throughput in order to calculate the two control law at once. Therefore, the HSWM(Hardware Switching Mechanism) of 2-processor concept is necessary. This paper addresses the concept of HSWM of the HQS-PC interface using TCP/IP(Transmission Control Protocol/Internet Protocol) communication based on flight control law of advanced supersonic trainer. And, the fader logic of TFS(Transient Free Switch) and stand-by mode of reset '0' type are designed in order to reduce the abrupt transient response and minimize the integrator effect in pitch axis. The result of the analysis based on HQS pilot simulation using HSWM reveals that the flight control systems are switching between two computers without any problem.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.5
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• pp.1111-1116
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• 2005

The necessity of the home network have been enlarged gradually according to the distribution of ultra-high speed internet, the expansion of a digital information equipment and the change of a life pattern. In this paper, we proposed the embedded ethernet module that could be operate on eight bit system, but it could control home appliance with full ethernet speed. The embedded ethernet module consists of 8051 MCU and Hardware TCP/IP. In this module, we construct simple web server and port remote control program for I/O device control. We verified through internet that the developed embedded ethernet module could control and check home appliances anywhere and anytime. We expect the developed ethernet module can build up niche market at home network. And it will be helpful to activate home network market.