• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.2 s.117
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• pp.126-135
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• 2007

This paper proposes a new miniaturization method for a parallel coupled line filter with enhanced bandwidth characteristics. A previous method incorporated several advantages, such as size reduction through the use of only a small number of capacitors, in addition to grounding, suppression of harmonic characteristics, and improved skirt characteristics for the parallel coupled line filter, which is conventional in the field of RE filters due to its design and fabrication simplicity. However, the previous method also has disadvantages related to the bandwidth shrinkage of the miniaturized filters. In this paper, the amount of bandwidth shrinkage is analyzed in terms of the relationship between the loaded Q(quality factor) and the group delay of a resonator. Moreover, the reduction in the bandwidth is solved by a design with new design equations. To show the validity of the proposed method, a hairpin filter with a center frequency of 5.2 GHz and an fractional bandwidth(FBW) of 10% was scaled down to half its original dimension by the proposed method with the enhanced bandwidth characteristics. The measured result shows a high level of agreement with theoretical results.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.10
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• pp.1540-1547
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• 2019

Objective: This study was conducted to evaluate the effects of tannins and cellulase on growth performance, nutrient digestibility, blood profiles, intestinal morphology, and carcass characteristics in Hu sheep. Methods: A total of 48 three-month-old meat Hu sheep ($25.05{\pm}0.9kg$) were blocked based on body weight, and randomly allotted to 4 treatments with 3 replicates of 4 sheep each. The experiment lasted for 80 d, and dietary treatments were as follows: i) CON, control diet; ii) TAN, CON+0.1% tannins; iii) CEL, CON+0.1% cellulase; iv) TAN+CEL, CON+0.1% tannins and 0.1% cellulase. Results: Compared with CON, CEL, and TAN+CEL had greater (p<0.05) final body weight (FBW) and average daily gain but lower (p<0.05) feed conversion ratio, while FBW of TAN+CEL was lower (p<0.05) than that of CEL. The apparent total tract digestibility (ATTD) of dry matter in TAN, CEL, and TAN+CEL groups were higher (p<0.05) than that in CON. CEL and TAN+CEL groups had greater (p<0.05) ATTD of crude fiber compared with TAN and CON, while TAN group had lower (p<0.05) ATTD of crude protein than other treatments. TAN, CEL, and TAN+CEL groups increased (p<0.05) serum globulin and alkaline phosphatase but decreased (p<0.05) albumin/globulin. Serum total protein was greatest for TAN+CEL, intermediate for TAN and CEL and least for CON (p<0.05). TAN+CEL group increased (p<0.05) dressing percentage compared with CON, while the backfat thickness of CEL was lower (p<0.05) than that of CON. The villus height of jejunum and ileum in CEL and TAN+CEL groups were greater (p<0.05) than that in CON, and the crypt depth and villus height: crypt depth of jejunum were increased (p<0.05) in TAN, CEL, and TAN+CEL groups. Conclusion: The addition of tannins and cellulase together promoted nutrient digestion, liver protein synthesis and intestinal development and thus improved growth performance and carcass characteristics.

• Current Industrial and Technological Trends in Aerospace
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• v.7 no.2
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• pp.85-94
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• 2009

The Fly-By-Wire system was first applied to the fighter and its inherent advantages lead to the advent of the Fly-By-Wire civil aircraft. Recently even the small jet aircraft shows the trend of adopting the Fly-By-Wire system. In the future, most of the aircraft are expected to be the Fly-By-Wire type. In this paper, the structure and the characteristics of the Fly-By-Wire system applied to the civil aircraft was described. The development trend of the redundant method of the flight control system, data communication system, control surface actuation system and the control laws implemented by the Fly-By-Wire system of the civil aircraft are discussed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.9
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• pp.867-873
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• 2008

Model based virtual Flight Control System construction is essential for Fly-by-Wire Flight Control System verification & validation(V&V) of concurrent engineering base. We researched the concept of dual-architecture system for virtual system construction, and analyzed Flight Control System that is applied to high altitude long endurance(HAE) UAS. Finally, we constructed the model based virtual Flight Control System with system analysis and achieved system verification about flight critical failure modes. Analysis target is RQ-4A.

• Aerospace Engineering and Technology
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• v.8 no.1
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• pp.172-178
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• 2009

Recently, autopilot is essential to reduce pilot's workload and increase flight safety. Avionics system of the small aircraft also has progressively adopted centralized multi-processor and multi-process computing architectures similar to the integrated modular avionics of B-777. It is increased more and more that importance of the flight control system. In this paper, the performance of the autopilot for the small aircraft has been verified with Hardware-In-the-Loop Simulation(HILS). Also, the autopilot algorithm that is operated in the Flight Control Computer(FCC) for the Fly by Wire(FBW) was verified with PILS and compared with the HILS results for the several commercial autopilots.

• BMB Reports
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• v.48 no.8
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• pp.431-437
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• 2015

Notch signaling plays a pivotal role in cell fate determination, cellular development, cellular self-renewal, tumor progression, and has been linked to developmental disorders and carcinogenesis. Notch1 is activated through interactions with the ligands of neighboring cells, and acts as a transcriptional activator in the nucleus. The Notch1 intracellular domain (Notch1-IC) regulates the expression of target genes related to tumor development and progression. The Notch1 protein undergoes modification after translation by posttranslational modification enzymes. Phosphorylation modification is critical for enzymatic activation, complex formation, degradation, and subcellular localization. According to the nuclear cycle, Notch1-IC is degraded by E3 ligase, FBW7 in the nucleus via phosphorylation-dependent degradation. Here, we summarize the Notch signaling pathway, and resolve to understand the role of phosphorylation in the regulation of Notch signaling as well as to understand its relation to cancer. [BMB Reports 2015; 48(8): 431-437]

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.7
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• pp.621-630
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• 2006

The T-50 advanced trainer aircraft combines advanced aerodynamic features and a fly-by-wire flight control system in order to produce a stability and highly maneuverability. The flight control system both longitudinal and lateral-directional axes to achieve performance enhancements and improve stability. The T-50 employs the RSS concept in order to improve the aerodynamic performance in longitudinal axis and the longitudinal control laws employ the dynamic inversion with proportional-plus-integral control method. And, lateral-directional control laws employ the blended roll system both beta-betadot feedback and simple roll rate feedback with proportional control method in order to guarantee aircraft stability. This paper details the design process of developing lateral-directional control laws, utilizing the requirement of MIL-F-8785C and MIL-F-9490D. And, this paper propose the analysis of aircraft characteristics such as dutch-roll mode, roll mode, spiral mode, gain and phase margin about gains for lateral-directional inner loop feedback.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.7
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• pp.713-718
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• 2006

Supersonic jet fighter aircraft have several different weapon loading configuration to support air-to-air combat and air-to-ground delivery of weapon modes. Especially, asymmetric loading configurations could result in decreased handling qualities for the pilot maneuvering of the aircraft. The design of the T-50 lateral-directional roll axis control laws change from beta-betadot feedback structure to simple roll rate feedback structure and gains such as F-16 in order to improve roll-off phenomena during pitch maneuver in asymmetric loading configuration. Consequently, it is found that the improved control law decreases the roll-off phenomenon in lateral axes during pitch maneuver, but initial roll response is very fast and wing pitching moment is increased. In this paper, we propose the lateral control law blending between beta-betadot and simple roll rate feedback system in order to decreases the roll-off phenomenon in lateral axes during pitch maneuver without degrading of roll performance.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.219-222
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• 2003

In this paper, we designed a Ku-band BPF(Band Pass Filter) by microstrip line that most usually used a microwave device design and fabrication. Here a substrate of designed BPF were silicon substrate(${\varepsilon}_r=11.8$), and metal line was copper and silver/copper structure. And a configration of BPF was used hairpin pattern. A center frequency of designed BPF was 10GHz and their FBW(Fractional Band Width) was 20%(2GHz). It presented simulated results obtained for a 10GHz filter which yields an insertion loss of 0.1dB that ripple value related chebyshev reponse. Finallt we tried to make that a 30dB attenuation frequency was 20% of center frequency.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.6
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• pp.89-102
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• 2010

In this paper, a study on the future-oriented actuator introduces the future technology and future direction in aerospace and several industry fields. In particular, the mechanical linkage or hydraulic and pneumatic actuators which have the higher output-to-weight ratio have been used a lot in the past as the aircraft's flight control device. Most recently, Fly-By-Wire system has been used in aircraft and the flight control system has been changed in more electric and all electric systems. Electrohydraulic actuators and electric actuators have been developed continually, because they have better efficiency, safety and lower cost for the flight control system of aircraft. Also, to improve the weight condition, accuracy and response of actuator, new field actuators using new materials have been developed. In this paper we clearly proposed the actuator design and detailed technology development trend for next generation actuation system in aerospace and new field.