• 동력기계공학회지
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• 제15권1호
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• pp.64-71
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• 2011

The Tension Leg Platform(TLP) is restrained from oscillating vertically by tethers(or tendons), which are vertical anchor lines tensioned by the platform buoyancy larger than the platform weight. Thus a TLP is a compliant structure which allows lateral movements of surge, sway, and yaw but restrains heave, pitch, roll. In this paper, the motions of a TLP in current and waves were investigated. Hydrodynamic forces and wave exciting forces acting on the TLP were evaluated using the three dimensional source distribution method. The motion responses and tension variations of the TLP were analyzed in the case of including current or not including one in regular waves and effects of current on the TLP were investigated.

• 한국소음진동공학회논문집
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• 제21권11호
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• pp.991-996
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• 2011

This study was carried out vibration attenuation of vibration absorber attached to the cantilever beam structure. Modern tank guns are stabilized to allow fire on the move while traversing uneven terrain. However, as the length of the barrel is extended, to meet required muzzle exit velocities, the terrain induced vibrations lead to increased muzzle pointing errors. Thus, reducing these vibrations should lead to increased accuracy. The vibration absorber includes a compliant energy storage device, such as a spring, and a mass secured to the energy storage device. In this study, it accomplished a research in about gun barrel vibration attenuation using tuned mass damper. The barrel was hung from a bungee cord for free-free condition. It accomplished a vibration experiment for verified attenuation efficiency.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.627-632
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• 2011

This study was carried out vibration attenuation of vibration absorber attached to the cantilever beam structure. Modern tank guns are stabilized to allow fire on the move while traversing uneven terrain. However, as the length of the barrel is extended, to meet required muzzle exit velocities, the terrain induced vibrations lead to increased muzzle pointing errors. Thus, reducing these vibrations should lead to increased accuracy. The vibration absorber includes a compliant energy storage device, such as a spring, and a mass secured to the energy storage device. In this study, it accomplished a research in about gun barrel vibration attenuation using tuned mass damper. The barrel was hung from a bungee cord for free - free condition. It accomplished a vibration experiment for verified attenuation efficiency.

• ETRI Journal
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• 제46권3호
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• pp.413-420
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• 2024

A dual-band bio-implantable compact antenna with a meander-line structure is presented. The proposed meander-line antenna resonates at the industrial, scientific, and medical (2.4 GHz) and wireless medical telemetry (1.4 GHz) bands. The meander-line structure is selected as a radiating patch given its versatile and effective design. With a dimension of only 10 mm × 10 mm × 0.635 mm, the designed antenna is compact. Considering a skin phantom, the proposed antenna was designed, optimized, and simulated. The Rogers RT/duroid 6010 substrate material with high dielectric constant was used to fabricate the meander-line dual-band implantable antenna, which was validated experimentally. The superstrate was made of the same material. Experiments were conducted on skin-mimicking gel. The designed meander-line antenna has a high peak gain of -21 dBi at 2.4 GHz, and its maximum specific absorption rate is compliant with IEEE safety standards.

• 한국지능시스템학회논문지
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• 제22권3호
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• pp.347-352
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• 2012

본 논문에서는 보행 로봇을위한 트러스 구조의 로봇 발 메커니즘을 제시한 후, 제시된 로봇 발 메커니즘의 특성을 분석하였다. 제시된 로봇 발 메커니즘은인간의 발의 구조적인 특징을 관찰하여 모델링 되었다. 특히, 인간의 발에 사용되고 있는 뼈대는 트러스로 나타내었고, 뼈대에 연결되어 있는 다양한 인대는 간단한 강성 요소로서 나타내었다. 따라서 이러한 로봇 발은 보행 로봇이 발걸음을 옮기는 과정에서 발에 작용되는 충격을 완화시킬 수 있는 장점을 갖는다. 결과적으로, 제안된 로봇 발 메커니즘은 보행로봇의 보행피로를 줄이는데 기여할 수 있다.

• Journal of Power Electronics
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• 제15권5호
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• pp.1409-1420
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• 2015

In this paper, an algorithm using two bi-quad filters to suppress the wide-band resonance for PMSM servo systems is proposed. This algorithm is based on the double bi-quad filters structure, so it is named, "double bi-quad filter." The conventional single bi-quad filter method cannot suppress unexpected mechanical terms, which may lead to oscillations on the load side. A double bi-quad filter structure, which can cancel the effects of compliant coupling and suppress wide-band resonance, is realized by inserting a virtual filter after the motor speed output. In practical implementation, the proposed control structure is composed of two bi-quad filters on both the forward and feedback paths of the speed control loop. Both of them collectively complete the wide-band resonance suppression, and the filter on the feedback path can solve the oscillation on the load side. Meanwhile, with this approach, in certain cases, the servo system can be more robust than with the single bi-quad filter method. A step by step design procedure is provided for the proposed algorithm. Finally, its advantages are verified by theoretical analysis and experimental results.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.410-413
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• 2012

A traditional fabrication method is very difficult to make small robots using embedded sensors, actuators and connectors. Fortunately, Shape Deposition Manufacturing can provide an alternative method, and it has many benefits. Firstly, the weight of robot can be lighter, as it can be consisted of composite materials. Secondly, SDM can make simple robot structures because this approach does not need to use connectors and fasteners. Lastly, SDM gives stiffness and flexibility at the specific parts. Therefore, in this paper, we present a design of 3 segment legs organized by SDM, what the SDM approach is, and compare SDM method with 3 segment prototype legs which uses a traditional approach and made by DGIST.

• 한국정보처리학회논문지
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• 제6권5호
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• pp.1153-1165
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• 1999

In various fields of information technology, it is growing up the needs about dynamic content management systems to store and manage SGML(Standard Generalized Markup language) documents in a database system. In this paper, we consider the issue of storing SGML documents that having complex hierarchical structure into a database system, and then propose a data model based on ODMG(Object Database Management Group) object model in order to store SGML documents without loss of information. Because the proposed data model reflects physical element structure and logical entity structure of SGML documents, it is able to store the SGML document in a database system at the system at the element- level granularity without any information loss. And also the proposed data model can be adapted among ODMG-compliant object database management systems. Finally, we will discuss on the implementation details of SGML repository system supports the functionality of automatic database schema creation for any DTD(Document Type Definition0, the functionality of storing the SGML document, the functionality of dynamic document assembly from stored database objects to SGML document, and the functionality of indexing and searching for database objects.

• 정보처리학회논문지B
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• 제12B권6호
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• pp.647-654
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• 2005

본 논문은 디지털방송 서비스의 필수 기술 요소이고 디지털방송 전환과 밀접하게 관련 있는 PSIP 응용 기술인 디지털방송 표준 인터페이스로 표준화된 PMCP(Program Metadata Control Protocol) 인터페이스 규격과, 이를 이용하여 구현된 지상파/케이블 데이터방송 재전송 서비스를 위한 PSIP 변환기의 구조 및 주요 기능에 대해서 기술한다. 본 논문의 PSIP 변환기는 지상파/케이블 데이터방송 재전송 서비스 환경하에서 디지털 지상파 데이터방송 콘텐츠를 디지털 케이블 데이터방송에 재사용하여 데이터방송 콘텐츠 활용도를 높일 뿐만 아니라 실시간 채널 정보 변경 및 방송 프로그램 이벤트 정보 변경만으로 지상파 방송프로그램 안내 정보를 쉽게 재활용/관리할 수 있다. 또한 저장/관리된 방송프로그램 안내 정보를 ATSC T3/Sl에서 표준화한 PMCP 규격을 이용하여 XML형태로 케이블 시스템(OOB SI, Out Of Band Service Information)으로 전송하거나, MPEG-2 전송스트림 형태로 전송할 수도 있다.

• Ocean Systems Engineering
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• 제11권1호
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• pp.17-42
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• 2021

Articulated loading platforms (ALPs) belongs to a class of offshore structures known as compliant. ALP motions have time periods falling in the wind excitation frequency range due to their compliant behaviour. This paper deals with the dynamic behavior of a double hinged ALP subjected to low-frequency wind forces with random waves. Nonlinear effects due to variable submergence, fluctuating buoyancy, variable added mass, and hydrodynamic forces are considered in the analysis. The random sea state is characterized by the Pierson-Moskowitz (P-M) spectrum. The wave forces on the submerged elements of the platform's shaft are calculated using Morison's Equation with Airy's linear wave theory ignoring diffraction effects. The fluctuating wind load has been estimated using Ochi and Shin wind velocity spectrum for offshore structures. The nonlinear dynamic equation of motion is solved in the time domain by the Wilson-θ method. The wind-structure interactions, along with the effect of various other parameters on the platform response, are investigated. The effect of offset of aerodynamic center (A.C.) with the center of gravity (C.G.) of platform superstructure has also been investigated. The outcome of the analyses indicates that low-frequency wind forces affect the response of ALP to a large extent, which otherwise is not enhanced in the presence of only waves. The mean wind modifies the mean position of the platform surge response to the positive side, causing an offset. Various power spectral densities (PSDs) under high and moderate sea states show that apart from the significant peak occurring at the two natural frequencies, other prominent peaks also appear at very low frequencies showing the influence of wind on the response.