• Journal of Institute of Control, Robotics and Systems
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• v.17 no.10
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• pp.1021-1028
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• 2011

The objective of this paper is to optimize the design parameters of a novel mechanism for a robotic knee orthosis. The feature of the proposed knee othosis is to drive a knee joint with independent actuation during swing and stance phases, which can allow an actuator with fast rotation to control swing motions and an actuator with high torque to control stance motions, respectively. The quadriceps device operates in five-bar links with 2-DOF motions during swing phase and is changed to six-bar links during stance phase by the contact motion to the patella device. The hamstring device operates in a slider-crank mechanism for entire gait cycle. The suggested kinematic model will allow a robotic knee orthosis to use compact and light actuators with full support during walking. However, the proposed orthosis must use additional linkages than a simple four-bar mechanism. To maximize the benefit of reducing the actuators power by using the developed kinematic design, it is necessary to minimize total weight of the device, while keeping necessary actuator performances of torques and angular velocities for support. In this paper, we use a SGA (Simple Genetic Algorithm) to minimize sum of total link lengths and motor power by reducing the weight of the novel knee orthosis. To find feasible parameters, kinematic constraints of the hamstring and quadriceps mechanisms have been applied to the algorithm. The proposed optimization scheme could reduce sum of total link lengths to half of the initial value. The proposed optimization scheme can be applied to reduce total weight of general multi-linkages while keeping necessary actuator specifications.

• Journal of the Semiconductor & Display Technology
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• v.12 no.2
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• pp.73-78
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• 2013

This paper proposes a portable electrocardiograph and smart device-based heart health monitoring and risk notification system. The proposed system consists of a portable electrocardiograph and a smart device for a system user, and a web-based monitoring system for observers. This system can improve the convenience and efficiency of measurement by using a light-weight portable electrocardiograph and a smart device. In addition, any authorized person such as caregiver or family member who is not related to medical institution can monitor users'heart health in real-time using the web-based monitoring system. Therefore, a user and authorized remote observers can efficiently monitor and manage user's heart health in daily-life even without any medical institution's help, and can preemptively deal with any possible dangerous situations, such as degeneration of a cardiac disorder and sudden cardiac death.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.5963-5967
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• 2014

Reducing the impact of collisions of cars is a major issue for reducing the injury and death of passengers. According to the statistical data of the Road Traffic Authority, the deaths from side collision accidents caused by the collision of passenger cars is greater than the deaths from head-on collision accidents. To accommodate this, vehicle designers have added a reinforcing material called the impact frame and impact beam on the inside of the door. Many experiments are needed to develop the door impact beam. These reinforcements to develop a collision experiment is essential. Collision experiments are costly and time consuming. This study used a drop Impactor to obtain the impulse and a strain experimental device was developed for this purpose. The economic costs were reduced and the ideal experiment device configuration was determined. A comparison of the experimental results with numerical value analysis revealed $3.5{\tiimes}10-3sec$ strain ranging from $3.49{\tiimes}10-3$ to $3.99{\tiimes}10-3$.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.9
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• pp.964-970
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• 2014

In this study we have developed an anthropomorphic robot hand and arm by using tendon-tubes which can be used for people's everyday life as a robot's dynamic power transmission device. Most previous robot hands or arms had critical problem on dynamic optimization due to heavy weight of power transmission parts which placed on robot's finger area or arm area. In order to resolve this problem we designed light-weighted robot hand and arm by using tendon-tubes which were consisted of many articulations and links just like human's hand and arm. The most prominent property of this robot hand and arm is reduction of the weight of robot's power transmission part. Reduction of weight of robot's power transmission parts will allow us to develop energy saving and past moving robot hands and arms which can be used for artificial arms. As a first step for real development in this study we showed structural design and demonstration of simulation of possibility of a robot hand and arm by tendon-tube. In the future research we are planning to verify practicality of the robot hand and arm by applying sensing and controlling method to a specimen.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.407-410
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• 2009

A piezoelectric device which converts mechanical vibration energy into electrical energy is able to harvest energy and the usable energy is mW ${\sim}$ W, hence a converter is necessary to acquire the energy efficiently. Various limited conditions should be considered for the design of AC/DC converter for energy harvesting of a piezoelectric device supplying small amount of energy. In addition to simple structure, compact size, light weight and high efficiency, the energy harvesting AC!DC converter should adopt the technique of self operating, in which only the harvested energy from the piezoelectric device is available. This paper proposes new AC/DC resonant boost converter to harvest efficiently electrical energy from mechanical vibration energy, analyzes the operating characteristics of the converter and proves its feasibility for energy harvester with PSPICE simulation and experiment.

• Rubber Technology
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• v.13 no.1
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• pp.1-9
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• 2012

Click chemistry had enjoyed a wealthy decade after it was introduced by K.B.Sharpless and his co-worker on 2001. Since there is no optimized method for synthesis of click polymer, therefore, this paper introduced three click reaction methods such as catalyst, non-catalyst and azide-end capping for fluorene-based functional click polymers. The obtained polymers have reasonable molecular weight with narrow PDI. The polymers are thermally stable and almost emitted blue light emission. The synthesized fluorene-based functional click polymers were characterized to compare the effect of click reaction methods on polymer electro-optical properties as well as device performance on quasi-solid-state dye sensitized solar cells (DSSCs) applications. The DSSCs with configuration of $SnO_2:F/TiO_2/N719$ dye/quasi-solid-state electrolyte/Pt devices were fabricated using these click polymers as a solid-state electrolyte components. Among the devices, the catalyzed click polymer composed device exhibited a high power conversion efficiency of 4.62% under AM 1.5G illumination ($100mW/cm^2$).These click polymers are promising materials in device application and $Cu^I$-catalyst 1, 3-dipolar cycloaddition click reaction is an efficient synthetic methodology.

• Journal of the Korea Safety Management & Science
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• v.20 no.2
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• pp.1-8
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• 2018

This study aims to provide a real-time information to the driver by effectively operating the advanced safety device attached to the freight vehicle, thereby minimizing insecure behavior of the driver such as speeding, rapid acceleration, sudden braking, And improve driving habits to prevent accidents and save energy. Advanced safety equipment is a device that warns the driver that the vehicle leaves the driving lane regardless of the intention of the driver and reduces the risk of traffic accidents by mitigating or avoiding collision by detecting a frontal collision during driving.The main contents of this report are as follows: In case of installing a warning device on a lane departing vehicle (excluding a light vehicle) and a lorry or special vehicle with a total weight exceeding 3.5 tonnes, the driver must continue to operate unless the driver releases the function.In addition, when the automatic emergency braking system is installed, the structure should be such that the braking device is operated automatically after warning the driver when the risk of collision with the running or stopped vehicle in the same direction is detected in front of the driving lane.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.4
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• pp.388-393
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• 2018

In this paper, We developed a high efficiency reflector integrated type 50W AC direct connection type engine to realize miniaturization and weight reduction of product without using SMPS and to design a multistage varistor circuit Reduced costs by reducing the number of parts High reliability is achieved by using a circuit structure that does not use an electrolytic capacitor, thus increasing the lifetime of the LED. In addition, it is possible to manufacture an AC direct-coupled type driving device by using an IC semiconductor and apply an AC direct-coupled type driving device integrated with a reflector so that the lifetime of the device can be fully utilized for the lifetime of the LED, A light source having a plurality of light emitting diode channels including a plurality of light emitting diode channels arranged in series is driven with a rectified voltage.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.169-176
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• 2011

The two-step water splitting thermochemical cycle is composed of the T-R (Thermal Reduction)and W-D (Water Decomposition)steps. The mechanism of this cycle is oxidation-reduction, which produces hydrogen. The reaction temperature necessary for this thermochemical cycle can be achieved by a dish-type solar thermal collector (Inha University, Korea). The purpose of this study is to validate a water splitting device in the field. The device is studied and fabricated by Kodama et al (2010, 2011). The validation results show that the foam device, when loaded with $NiFe_2O_4/m-ZrO_2$powder, was successfully achieved hydrogen production with 9 (10 with a Xe-light solar simulator, 2009, Kodama et al.) repeated cycles under field conditions. Two foam device used in this study were tested for validation before an experiment was performed. The lab scale ferrite-conversion rate was in the range of 24~76%. Two foam devices were designed to for structural stability in this study. In the results of the experiments, the hydrogen percentage of the weight of each foam device was 7.194 and $9.954{\mu}mol\;g^{-1}$ onaverage, and the conversion rates 4.49~29.97 and 2.55~58.83%, respectively.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.505-508
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• 2004

단열완충재 제품간의 경량충원 저감성능 평가를 객관적이고 신속하게 판별하기 위하여 실험실용 시험장치를 개발하였다. EVA계열 및 EPPㆍEPS계열의 단열완충재들에 대한 경량충격원 시험에서 제품간의 성능비교가 가능하였으며, 동탄성계수 및 손실계수 측정과 병행함으로써 제품들간의 우열성을 보다 정밀하게 평가할 수 있었다.