• Land and Housing Review
• /
• v.2 no.4
• /
• pp.553-558
• /
• 2011

Existing method protruding strands that are embedded in PHC pile to connect pile head and foundation slab shows poor constructibility. As this causes crack and damage in pile head and casualties often occurs in construction site during the work, alternative method called one-cutting method, in which pile above the ground surface and strands embedded in pile are completely cut and pile head is reinforced with rebar for connection with foundation slab, is currently adopted. However, the capacity of details for these methods are not mechanically proved. In this study, in order to suggest proper details of reinforcement for one-cutting method, failures due to lack of shear resistance between infilled concrete and PHC pile are analyzed through experiments and embedded depth with infilled concrete inside PHC pile is suggested. Assuming that slip failure strength is 0.4MPa, which is obtained from experiment conservatively, to have rebar yielded before slip failure, minimum depth of infilled concrete for PHC 450 and PHC 500, need to be 600mm above, and for PHC 600, 1,000mm above.

• Journal of Software Assessment and Valuation
• /
• v.16 no.2
• /
• pp.127-133
• /
• 2020

As the usages of artificial intelligence is increased, the demand to algorithms for small portable devices increases. Also as the embedded system becomes high-performance, it is possible to implement algorithms for high-speed computation and machine learning as well as operating systems. As the machine learning algorithms process repetitive calculations, it depend on the cloud environment by network connection. For an stand alone system, low power consumption and fast execution by optimized algorithm are required. In this study, for the purpose of smart control, an energy measurement sensor is connected to an embedded system, and a real-time monitoring system is implemented to store measurement information as a database. Continuously measured and stored data is applied to a learning algorithm, which can be utilized for optimal power control, and a system interfacing various sensors required for energy measurement was constructed.

• Journal of KIISE:Computing Practices and Letters
• /
• v.14 no.4
• /
• pp.389-400
• /
• 2008

As the wireless network technologies and the capability of the mobile terminals are evolving, advanced peer to peer applications for mobile users are attracting interests. In this paper, we propose the mobile P2P communication platform(MPCP) which provides transparency to the wireless network technologies and solutions to the limited resources of the mobile terminals. MPCP classifies the connection into two levels: a virtual channel and a session. A virtual channel is the network layer connection between the terminals whereas a session is the application layer connection. MPCP classifies the sessions into four types and applies different scheduling priority and data processing policies such as segmentation and reassembly. It selects proper wireless network technologies depending on the distance between the communication endpoints. To acquire dynamically changed access address, we harness the Session Initiation Protocol. We implemented MPCP on embedded Linux simulator and utilized the implementation in mobile P2P service development. For the quantitative analysis, we compared the performance of MPCP with that of ftp. Regardless of the number of simultaneous sessions, MPCP maintains the relative performance.

• The Journal of Korean Academy of Prosthodontics
• /
• v.35 no.4
• /
• pp.793-800
• /
• 1997

Periotest(Siemens, Germany) has been used to test mobility of the implants clinically, however the effects of target materials and connection methods on the PTVs(Periotest Values) have not been evaluated. Periotest has been regarded as a reliable and objective tool to test implant and natural teeth mobility clinically, however this instrument showed different PTVs under various test conditions. This in vitro study was designed to compare PTVs of different veneering materials and prosthodontic designs (single and bridge restorations). To compare the effects of veneering materials on PTVs, 1 mm thickness of five different testing materials (porcelain, type III gold alloy, pure titanium, composite resin, acrylic resin) were placed on the resin block. Three full length of 13 mm Mark II implant fixtures were embedded into autopolymerizing resin block to fabricate single and bridge restorations. To evaluate effects of the connection method in single restorations, PTVs of screw retained(UCLA type) and cementation type(Cera-One system) were compared. Finally, to test reliability of PTVs of the final restorations, screw retained three unit short span PFM bridges were fabricated on the standard and Estheti-Cone abutments. All testing components were tightened with torque controller and PTVs of all specimens were measured 15 times for statistical analysis with SAS program. Following conclusions were made within the limit of this in vitro study. 1. PTVs of type III gold alloy, grade II titanium, composite resin veneering materials showed no significant differences, however acrylic resin and porcelain showed significant differences (P<0.05). 2. Single tooth restorations showed consistent PTVs as long as proper torque force was applied. 3. PTVs of bridge type prostheses was inconsistent regardless of abutment types. 4. PTVs of the prostheses showed higher scores and standard deviations than those of abutments regardless types of connection (P<0.05).

• Journal of KIISE:Software and Applications
• /
• v.28 no.2
• /
• pp.113-123
• /
• 2001

본 논문에서는 CAN 기반 분산 제어 시스템을 위한 환경 명세 CORBA인 CAN-CORBA를 설계한다. CAN-CORBA의 ORB core는 다음과 같은 특성을 지닌다. (1) 기존의 접속 지향 점대점 통신뿐만 아니라 가입 기반(subscription-based)의 그룹 통신을 지워난다. 이를 통해, 결과적으로 전형적인 제어 시스템의 데이터 멀티캐스팅(multicasting) 요구를 한층 충족시킨다. (2) CORBA 메소드(method) 호출에 필요한 메시지 전송량을 크게 감소시킨다. CAN 같은 저속 브로드케스트(broadcast) 버스에서도 CORBA 메소트 호출의 오버헤드를 감당 할 수 있게 한다. 자연스럽게 두 종류의 통신 방법을 본 논문에서 제안한 매우 작은 크기의 ORB에 통합하기 위하여, 최대 4가지의 상위 통신규약을 지원할 수 있는 CAN의 전송층(Transport layer) 통신규약을 설계한다. 또한 서울대학교에서 이미 개발된 mArx라는 실시간 운영체제 환경에서 CAN-CORBA를 구현하였다. 성능 평가를 통하여 매우 제한적인 자원을 지니는 분산 내장형 제어 시스템 개발에 CORBA를 사용하는 것이 매우 적합하다는 결과를 보인다.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.912-916
• /
• 2004

The home network is the technique to guarantee a safe, economical, socially integrated, and healthy life to the family and it provides domestic safety, instrument control, controllable energy and health monitoring by the connection of the home appliances using wired and wireless networks. A home control system has been developed for managing and controlling home appliances. This paper designs the broadband PLC home controller using broadband PLC technology which can save much cost at a network infrastructure using the existing power line at a home and design the USB home controller using USB technology which is low cost and has many goods with it. And the embedded home server manages those. The CDMA module provides mobile functions to the home control system in this paper. And we choose the OSGi specification which is compatible with other home middleware and can accept various communication techniques of home network

• KCI Concrete Journal
• /
• v.13 no.2
• /
• pp.67-74
• /
• 2001

In this study, a numerical model for the simulation of reinforced concrete columns subject to cyclic loading is presented. The model consists of three separate models representing concrete, reinforcing steel bars and bond-slip between a reinforcing bar and ambient concrete. The concrete model is represented by the plane stress plastic-damage model and quadrilateral finite elements. The nonlinear steel bar model embedded in truss elements is used for longitudinal and transverse reinforcing bars. Bond-slip mechanism between a reinforcing bar and ambient concrete is discretized using connection elements in which the hysteretic bond-slip link model defines the bond stress and slip displacement relation. The three models are connected in finite element mesh to represent a reinforced concrete structure. From the numerical simulation, it is shown that the proposed model effectively and realistically represents the overall cyclic behavior of a reinforced concrete column. The present plastic-damage concrete model is observed to work appropriately with the steel bar and bond-slip link models in representing the complicated localization behavior.

• Journal of Chest Surgery
• /
• v.19 no.2
• /
• pp.335-340
• /
• 1986

Pulmonary arteriovenous fistula is unusually congenital malformation consisting of an abnormal connection between a pulmonary artery and vein. It may appear as an isolated anomaly or with hereditary hemorrhagic telangiectasis. In the classic form, symptoms and signs are caused by the abnormal right to left shunt. since severe clinical symptoms such as paradoxical embolism, infection, and spontaneous rupture with massive bleeding may occur, surgical treatment is often indicated. Recently we have experienced a surgical treatment of pulmonary arteriovenous fistula in 54 years old housewife. She was admitted in May 1986 with recurrent hemoptysis for 1 month. On admission, the PaO2 was 65.2 mmHg without specific findings. Pulmonary arteriovenous fistula was confirmed by preoperative pulmonary arteriography. A well circumscribed cystic mass was noted in visceral subpleural and inferior lingular segment of left upper lobe. Left upper lobectomy was performed with good results. Histologically angiomatous dilatation of abnormal vessels embedded in lung parenchyma was noted. Postoperative PaO2 was 90 mmHg. Postoperative results were good.

• Structural Engineering and Mechanics
• /
• v.3 no.4
• /
• pp.299-312
• /
• 1995

A new reinforcing steel model which is embedded inside a concrete element and also accounts for the effect of bond-slip is developed. Unlike the classical bond-link or bond-zone element using double nodes, the proposed model is considering the bond-slip effect without taking double nodes by incorporation of the equivalent steel stiffness. After calculation of nodal displacements, the deformation of steel at each node can be found through the back-substitution technique from the first to the final steel element using a governing equation constructed based on the equilibrium at each node of steel and the compatibility condition between steel and concrete. This model results in significant savings in the number of nodes needed to account for the effect of bond-slip, in particular, when the model is used for three dimensional finite element problems. Moreover a new nonlinear solution scheme is developed in connection with this model. Finally, correlation studies between analytical and experimental results and several parameter studies are conducted with the objective to establish the validity of the proposed model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.05a
• /
• pp.303-310
• /
• 2002

The bending vibration and thermal flutter instability of spacecraft booms modeled as circular thin-walled beams of closed cross-section and subjected to thermal radiation loading is investigated in this paper. Thermally induced vibration response characteristics of a composite thin walled beam exhibiting the circumferantially uniform system(CUS) configuration are exploited in connection with the structural flapwise bending-lagwise bending coupling resulting from directional properties of fiber reinforced composite materials and from ply stacking sequence. The numerical simulations display deflection time-history as a function of the ply-angle of fibers of the composite materials, damping factor, incident angle of solar heat flux, as well as the boundary of the thermal flutter instability domain. The adaptive control are provided by a system of piezoelectric devices whose sensing and actuating functions are combined and that an bonded or embedded into the host structure.