Bluetooth Ad hoc 망에서 멀티 슬롯 SAR-QT 알고리즘을 고려한 WAP 패킷의 성능 분석

문일영,노재성,조성준 한국항행학회 2002 韓國航行學會論文誌 Vol.6 No.2

본 논문은 Bluetooth환경에서 SAR-QT(Segment And Re-assembly Quick Transfer)알고리즘을 사용하여 WAP (Wireless Application Protocol)성능을 향상시키기 위한 ,WAP패킷의 전송 시간을 분석하였다. 이러한 WAP의 전송 능력을 향상시키기 위한 한 방법으로 SAR-QT의 과정은 WTP (Wireless Transation Protocol)상위 계층에서 내려온 전체 메시지를 분할한 다음, 베이스밴드에서 패킷을 전송하게 된다. 그리고 Bluetooth 패킷 타입중의(Data-Medium rale) 1, DM3, DM5, 에 따른 WAP over Bluetooth의 패킷 전송 시간을 분석하였다. 이 SAR-QT 알고리즘은 멀티 슬롯으로 전송할 경우 L2CAP (Logical Link Control And Adaptation Protocol)베이스밴드 패킷 전송 시간을 감소 시킨다. 결과로부터, WAP over Bluetooth 환경에서 WAP 패킷의 전송 시간을 줄이기 위해서 WP패킷 크기가 증가해야 한다는 점을 알 수 있었다. 또한, 이러한 무선 채널을 고려한, Rician 페이딩 환경에서 WAP over Bluetooth의 적당한 패킷 크기를 구할 수 있었다. In this paper, it is analyzed that WAP pachket transmission time to improve performance of WAP using SAR-QT algorithm in Bluetooth channel. The order for SAR-QT algorithm to improve the transfer capability, it is fragmented in WTP total messages that are coming down from upper layer and then the packets are sent one at time in baseband. And it is studied that transmission time for WAP over Bluetooth according to DMI, DM3 or DM5 packet type using SAR-QT algorithm in Bluetooth piconet environment. This SAR-QT algorithm decreases WAP packet transmission time of L2CAP baseband packets by sending packet that are spanning multiple slots. From the results, in WAP over Bluetooth channels, it is found out that WTP packet size ougth to be increased to decrease transmission time of WAP packet. In addition, considering BER in wireless channel. optimal WTP packet size is achieved for WAP over Bluetooth in a Rician fading environment.

X선 촬영인자의 변화에 따른 영상의 주관적인 화질 평가

권덕문,박명환,김성환,박종삼,이준일,남효덕 대구보건대학 2001 대구보건대학 論文集 Vol.21 No.-

In this study, visual recognition of X-ray images were estimated using hawlet charts. The resolution has achieved excellent result when densities of film were 1.0~1.5. The more thickness of object was increase, the more the resolution was decrease, because scattered X-ray were increased. The more distance of object to film was increase, the more the resolution was decrease, because groedel effect. The more focal spot size was increase, the more resolution was decrease, because unsharpness was increase. The more field size was increase and grid ratio was decrease, the more resolution was decrease, because scattered X-ray were increase. As a result, we could to improve image quality by determination of resolution according to Radiography parameters. And, we proved that hawlet charts were useful for estimate of image quality and set up x-ray radiography.

복부 X선촬영에서의 결석의 확대율 검토

권덕문,박종삼,박명환,이준일 대구보건대학 1995 대구보건대학 論文集 Vol.15 No.-

This experiment was done in order to give some help for stone doigonosis. After calculating theoretical value and interposition stone at the phantom which set at the same position with human and radiography, we compared both magnification degree and the conclusion is like this. 1. The average distance from dorsal to kidney pelvis is 7.7㎝, to middle ureter is 11. 1㎝ and to ureter bladder jucntion is 9.5㎝. 2. In the case of the same abdomen thickness, the distance error at each part and in personal was ± 5%. 3. Magnification degree at each part of abdomen was shown that it was 1.17 times at kidney plvis, 1.12 times at middle urter and 1.2 times ureter bladder junction.

Star Test Pattern을 이용한 X-선관 등가초점의 측정

권덕문,박종삼,이준일,남효덕 대구보건대학 1999 대구보건대학 論文集 Vol.19 No.-

In this study, equivalent focal spot sizes of X-ray tube were measured by star test pattern. As a result, the focal size was proportional to tube current and inversely proportional to tube voltage. Although tube current was increased the focal size was almost constant, when tube voltage is large than 80kVp. And, focal size was more increased at high tube current or low tube voltage. Resolution was more excellent if focal size was small. We confirmed what the radiation energy was distributed as edge band distribution in focus, because the intensity of energy at side was larger than in center.

前腕部 經穴 取穴에서 骨度分寸法과 一夫法의 比較 硏究

박히준,채윤병,차웅석,박종배,이혜정,이향숙,인창식,고형균,김수영,최일환,김강식,문정배,배기태,유경환,육근영,정병주,손인철,임사비나 WHO COLLABORATING CENTRE FOR TRADITIONAL MEDICINE 2004 東西醫學硏究所 論文集 Vol.2004 No.-

Background : The cun measurement System, an essential and convenient method in locating acupoints, has been widely used in the practice of acupuncture. However, traditional cun measurement has been criticized for its lack of reliability. Objectives : The purposes of this study are to determine if one cun measured by the directional methods have a consistency with that of proportional methods and to investigate which factors are related with these differences, especially in forearm. Methods : The distance between the elbow crease and the wrist crease of forearm was compared to a reference value of one cun obtained by the directional method. In this method, one cun is one third of the distance between index finger and Small finger of a subject, measured at proximal interphalangeal joint. In addition, to investigate the factors influencing the differences between these two methods, we measured the height and body weight and calculated body mass index (BMI). Finally we analyzed the factors correlated with these lengths by linear regression test. Results : The results showed that one cun obtained by the directional methods were significantly different from one cun by the proportional methods in forearm. It was demonstrated that the length acquired with the directional method was more correlated with body weight and body mass index, while the length obtained by the proportional method was more correlated with the height.

高靭性 纖維補强 시멘트 複合體를 使用한 耐震要素의 履歷特性

양일승,윤현도,김선우,박완신,한병찬,문연준 대한건축학회 2005 大韓建築學會論文集 : 構造系 Vol.21 No.1

Concrete is one of the principal materials for the structures and It is widely used all over the world While advanced technologies of concrete have been recently focused especially on developing high performance concrete In which possess high compressive strength and durability, such concrete shows extremely brittle failure under shear and tension To Improve such a poor properties, high performance fiber reinforced cement composites(HPFRCC) has been developed For forming multicrack, a large number of fiber and/or the high specific area with thinner fibers are required However, It causes difficulties for the extrusion because of the poor workability So, this theses was suggested adequate mixing method and mix proportion for cach fibers and experimentally observed Structural performance of the seismic devices made by steel bar and HPFRCC These dampers will be applied for reducing damage as weil as seismic response The advantages of the HPFRCC damper is selective structural performance, strength, stiffness, and ductility by changing configuration, bar arrangements and type of materials used The experimental results indicate that elemental ductility is much increased with decreasing damage when the HPFRCC are applied to the damper It means cementitious seismic damper for structure control is available, which has much merit in performance and cost

Sn-Ag-Bi-In계에서의 Bi, In 첨가영향

김문일,문준권,정재필 서울시립대학교정보기술연구소 2001 정보기술연구소 논문집 Vol.3 No.-

Sn-3Ag-8Bi-5In and Sn-X solders of intermediate melting point were investigated for the application of Pb-free solder. Even though In-contained solder is expensive, the melting temperature of this solder is lower than that of the Sn-Ag-Cu alloy. The melting temperature of the Sn-3Ag-8Bi-5In solder on this study is between 188 and 204℃. The results of the wetting test showed that the wetting force and the zero-cross-time of the Sn-3Ag-8Bi-5In solder to Cu-coupon were comparable to Sn-Pb eutectic. The solder ball, which has 0.5mm diameter, was set on the Au/Ni/Cu-pad of FR4-PCB (Printed Circuit Board) and reflowed with Rosin Mildly Activated (RMA)-flux in the air. The reflow temperature was set between 220 and 260℃, and the conveyor speed was between 0.6 and 0.9m/min. Then the shear strength and microstructure of the solder ball were evaluated with or without aging. The solder balls were aged at 110℃ for 860 hours. The shear strength of the Sn-3Ag-8Bi-5In solder ball reflowed at 220∼260℃ was about 410∼540gf as soldered state and it showed same level as Sn-37Pb. The shear strength increased rapidly after aging, about 25% for the first 96 hours of aging. After that, the shear strength became almost constant, with the value of 600gf. Shear strength of Sn-X alloys showed similar values as Sn-37Pb.

溫度振動法을 利用한 化合物半導體單結晶의 生長硏究

金顯昌,權秀逸,鄭汶奎,張浚成 成均館大學校 1981 論文集 Vol.29 No.-

This paper describes the merit of the HgI_2 single crystals obtained by solution growth, 2-& 3-region temperature growth, and temperature oscillation growth for soft γ-ray detectors which can be operated at room temperature. Special efforts are put on the design, construction, and operation of the TOM single crystal growing furnace. Experimental results show that HgI_2 detectors fabricated by vapour phase growth method usually exibit sufficient enough detector characteristics for soft γ-ray spectrometry. However further investigation should be carried out to eliminate detector deterioration due to polarization effect.

복합섬유 보강 고인성 시멘트 복합체의 특성

윤현도,양일승,한병찬,福山洋,전에스더,문연준 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

In this paper, workability, fiber dispersion. compressive strength and splitting strength of hybrid fiber reinforced cement composites(HFHCC) have been investigated by means of Korean Standard (KS). Two type of HFRCC were constructed using fiber combinations of Polyethylene(PE) and steel fibers. Polyvinyl alcohol(PVA) and steel fibers. Test results showed that the fibers, when used in a hybrid form. could result in superior composite performance compared to their individual fiber reinforced cement Composites. Synthetic micro fibers. such as PE and PVA. are effective at imparting fiber dispersion and ductility to the steel fiber (five twisted steel fiber) reinforced cement Composite.

복합섬유 보강 고인성 시멘트 복합체의 인장거동

윤현도,양일승,한병찬,福山洋,전에스더,문연준 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

An overview of the response highly ductile hybrid fiber reinforced cementitious composites to bending loading, direct tensile loading, and cyclic loading in both tension and compression is presented. Hybrid fiber reinforced cement composites(HFHCC) contains both of specially processed steel fiber( steel cord) and synthetic fiber. such as. Polyethylene(PE) and Polyvinyl alcohol(PVA). As the result of the bending tests. HFHCC specimen shows multiple cracking in the area subjected to the greatest bending tensile stress. Uniaxial tensile test confirms the range of tensile strain capacity from 0.5 to 1.5% when hybrid fiber is used. The cyclic loading test results identified a unique unloading and reloading response for this ductile composite. Cyclic loading in tension appears not to affect the tensile response of the material if the uniaxial compressive strength during loading is not exceeded.