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Commercialised laparoscopic surgical robotic systems require a large operating room and can only be used in large hospitals. If the robotic system is to be used in a small- or medium-sized hospital, the occupied volume must be reduced further.In this paper, we propose a bed-mounted system that can be installed in a general operating room. Furthermore, we proposed a novel positioning arm suitable for a bed-mounted surgical robot system.The surgical possibility of the proposed bed-mounted system has been verified. Furthermore, the surgical possibility of the proposed system was confirmed using in vivo animal experiments.A bed-mounted laparoscopic robotic system and a novel positioning arm was proposed. The study's ultimate goal is to enable robotic surgery in small and medium-sized hospitals by introducing the proposed bed-mounted laparoscopic robot system, allowing many people to receive high-quality medical services.

Background Intraocular surgery and reconstructive surgery are challenging microsurgery procedures that require two types of motion: precise motion and larger motion. To effectively perform the requisite motion using a robot, it is necessary to develop a manipulator that can adjust the scale of motion between precise motion and less precise, yet larger motion. Aims In this paper, we propose a novel microsurgery robot using the dual delta structure (DDS) to mechanically scale the motion to seamlessly adjust between precise and larger motion. MATERIALS & METHODS: The DDS forms a lever mechanism that enables the motion scaling at the end-effector using two delta platforms. Seamless scale adjustment enables the robot to effectively perform various surgical moves. Results A prototype robot system was developed to validate the effectiveness of the DDS. The experiment results in various scale settings validated the scaling mechanism of the DDS. Conclusion Through a graphical simulation and measurement experiment, the robot's precision level and attainable workspace has been confirmed adequate for intraocular and reconstructive surgery.

Piston bowl geometries are critical to the combustion and emission characteristics of diesel engines. The present study investigated chamfered-bowl designs and biodiesel blending under a low-temperature combustion regime in order to achieve ultra-low particulate combustion (ULPC). The target soot level for ULPC was set at a filter smoke number value of 0.1 and engine experiments were conducted at the medium load condition. The injection visualization experiment provided the start of injection difference between the diesel and biodiesel fuels, while a three-dimensional computational simulation was conducted to examine the spray and combustion phenomena inside the engine cylinder. The experimental engine was a 1 l single-cylinder diesel engine equipped with a common-rail direct-injection system. The engine was operated at a speed of 1400 rev/min and the intake pressure was set at 200 kPa for a 50 per cent load condition. Two chamfered-bowl pistons were prepared for comparison with the conventional re-entrant bowl piston, and the experimental results showed that the chamfered-bowl pistons achieved significant soot reduction. In addition, computational analysis using a KIVA model showed that the chamfered bowls achieved wider fuel distribution and enhanced combustion. Biodiesel blending further reduced soot emission, and an increase in nitric oxides with biodiesel blends was also observed.

According to the regulation on the environment and fuel efficiency is becoming strict, many experiments are conducted to improve efficiency and emission in internal combustion engines. LTC (Low temperature combustion) technology is a promised solution for low emissions but there are a few barriers for the commercial engine. This paper includes optimization that applies LTC method to heavy duty diesel engine. Adequate LTC was applied to low and middle load as adaptability in heavy duty diesel engine, and optimization focused on reduction of fuel consumption was proceeded at high load. Through this research, strategy for practical use of LTC was selected, and fuel consumption has improved on the condition that satisfies the emission regulation at systematic viewpoint. Key words : Heavy duty diesel engine( 대형디젤엔진), HP-EGR(High Pressure loop EGR, 고압 배기재순환), LP-EGR (Low Pressure loop EGR, 저압 배기재순환), VGT Turbocharger (Variable Geometry Turbine Turbocharger, 가변 터빈 터보차져), LTC(Low Temperature Combustion, 저온연소)

LTC(Low Temperature Combustion) technology has been studied to see feasibility of the combustion technology applied to heavy-duty engines on the laboratory scale. This study succeeded to develop a demo engine including realized low temperature combustion under partial load conditions. To find the best feasible LTC strategy, various LTC combustion methods such as PPCI, MK and highly diluted mixing controlled LTC were conducted on 6.0L heavy duty diesel engine. Air management system was re-designed to make these combustion scheme stable and the re-designed air system helped expand LTC operating range. This study finally revealed plausible LTC concept to maximize benefit of the alternative combustion technology while overcoming handicaps of the LTC strategy. Key words : Low temperature diesel combustion(저온디젤연소), Partially pre-mixed combustion ignition(예혼합연소), EGR(배기가스 재순환), Low pressure EGR(저압-배기가스재순환), NOx(질소산화물), PM(입자상물질), HD diesel engine(대형디젤엔진) Nomenclature 1) LTC : low temperature diesel combustionPPCI : partially pre-mixed combustion ignitionMK : modulated kineticsCDC : conventional diesel combustionEGR : exhaust gas recirculationHP-EGR : high pressure EGRLP-EGR : low pressure EGRNOx : nitrogen oxidesPM : particulate matterHC : hydro carbon

This study researched on the effect of HP/LP-EGR system to improve fuel consumption of Low Temperature Combustion Engine. Firstly, low temperature combustion engine with HP/LP-EGR system was established using 6.0L wastegate turbocharger HDDI engine. And suppliable EGR rate of the engine was proven to be enough to realize stable low temperature combustion. Then, optimum operating strategy was founded to develop fuel consumption of the engine. Control parameters were HP/LP-EGR valve and IPCV(Intake Pressure Control Valve) duty. Experiments method was that characteristics of the engine were measured and analyzed according to HP/LP-EGR strategies while EGR rate was fixed. Operating range for the strategy were divided into three parts, low load for low temperature combustion, high load for conventional diesel combustion, and transient condition.Finally, with the above strategy of this study, BSFC of the engine was improved about 2% compared to the base engine, and emission level, NOx and PM, met Tier4Final emission regulation.Key words : DI engine( w®uþkqn™ sAw± ), HP-EGR( ZIsB j \ u™p „E ), LP-EGR( uisB j \ u™p „E ), Low temperature combustion( uit sÝoy ), Turbocharger(  jaz ui ), Exhaust pressure( j \ sBf ), Intake pressure( N\ sBf ), BSFC( v aAEsÝf¹oyl1u ), PMEP( yƒ>o}pN )

One of the effective ways to reduce both NOx and PM at the same time in a diesel CI engine is to operate the engine in low temperature combustion (LTC) regimes. In general, two strategies are used to realize the LTC operation-dilution controlled LTC and late injection LTC - and in this study, the former approach was used. In the dilution controlled regime, LTC is achieved by supplying a large amount of EGR to the cylinder. The significant EGR gas increases the heat capacity of in-cylinder charge mixture while decreasing oxygen concentration of the charge, activating low temperature oxidation reaction and lowering PM and NO x emissions. However, use of high EGR levels also deteriorates combustion efficiency and engine power output. Therefore, it is widely considered to use increased intake pressure as a way to resolve this issue. In this study, the effects of intake pressure variations on performance and emission characteristics of a single cylinder diesel engine operated in LTC regimes were examined. LTC operation was achieved in less than 8% O 2 concentration and thus a simultaneous reduction of both PM and NOx emission was confirmed. As intake pressure increased, combustion efficiency was improved so that THC and CO emissions were decreased. A shift of the peak Soot location was also observed to lower O2 concentration while NOx levels were kept nearly zero. In addition, an elevation of intake pressure enhanced engine power output as well as indicated thermal efficiency in LTC regimes. All these results suggested that LTC operation range can be extended and emissions can be further reduced by adjusting intake pressure.

In this paper, we present a robotic actuation system using an artificial muscle actuator based on a dielectric elastomer. A novel linear actuator called a 'multi-stacked actuator' is proposed that can be embedded in the phalanges of a multi-jointed robot finger. This actuator ensures a compact design of the overall system. As an example, a 2-d.o.f. robot finger is developed and its performance under the proposed actuator system is experimentally demonstrated. The application of the proposed system can be extended easily to a multifingered robot hand and even to articulated mechanisms such as legged robots, etc.

A new biomimetic actuation system by artificial muscle actuator based on dielectric elastomer is presented in this paper. A novel linear actuator called “multi-stacked actuator” is introduced, which can be embedded in the phalanges of the finger and ensures a compact design of the overall system. The performance of the proposed actuation system is demonstrated using two degree–of–freedom robot finger. A pulse-width-modulation proportional-integral-derivative (PWM-PID) feedback controller based on the discharging circuit is implemented and tested. The proposed system can be extended to the multi–fingered robot hand easily, and applied even for articulated mechanisms such as legged robots etc.

The present study investigated the effects of biodiesel blending under a wide range of intake oxygen concentration levels in a diesel engine. This study attempted to identify the lowest biodiesel blending rate that achieves acceptable levels of nitric oxides (NOx), soot, and coefficient of variation in the indicated mean effective pressure (COVIMEP). Biodiesel blending was to be minimized in order to reduce the fuel penalty associated with the biodiesels lower caloric value. Engine experiments were performed in a 1-liter single-cylinder diesel engine at an engine speed of 1400 rev/min under a medium load condition. The blend rate and intake oxygen concentration were varied independently of each other at a constant intake pressure of 200 kPa. The biodiesel blend rate varied from 0% (B000) to 100% biodiesel (B100) at a 20% increment. The intake oxygen level was adjusted from 8 to 19% by volume (vol %) in order to embrace both conventional and low-temperature combustion (LTC) operations. A fixed injection duration of 788 μs at a fuel rail pressure of 160 MPa exhibited a gross indicated mean effective pressure (IMEP) between 750 kPa and 910 kPa, depending on the intake oxygen concentration. The experimental results indicated that the intake oxygen level had to be below 10 vol% to achieve the indicated specific NOx (ISNOx) below 0.2g/kWhr with the B000 fuel. However, a substantial soot increase was exhibited at such a low intake oxygen level. Biodiesel blending reduced NOx until the blending rate reached 60% with reduced in-cylinder temperature due to lower total energy release. As a result, 60%-biodiesel blended diesel (B060) achieved NOx, soot, and COVIMEP of 0.2 g/kWhr, 0.37 filter smoke number (FSN), and 0.5, respectively, at an intake oxygen concentration of 14 vol%. The corresponding indicated thermal efficiency was 43.2%.

In this paper, we present a new haptic interface, called "active skin", which is configured with a tactile sensor and a tactile stimulator in single haptic cell, and multiple haptic cells are embedded in a dielectric elastomer. The active skin generates a wide variety of haptic feel in response to the touch by synchronizing the sensor and the stimulator. In this paper, the design of the haptic cell is derived via iterative analysis and design procedures. A fabrication method dedicated to the proposed device is investigated and a controller to drive multiple haptic cells is developed. In addition, several experiments are performed to evaluate the performance of the active skin.

In this paper we present a robotic actuation system by artificial muscle actuator based on dielectric elastomer. A novel linear actuator called “multi-stacked actuator” is presented, which can be embedded in the phalanges of the finger and ensures a compact design of the overall system. As an exemplary work, a two degree-of-freedom robot finger is developed and its performance is experimentally demonstrated. The proposed system can be extended to the multi-fingered robot hand easily, and applied even for articulated mechanisms such as legged robots etc.

In this paper we present a dielectric elastomer actuator, which has the ability to sense the force acting on itwithout any additional sensing device. Basic physical b ehaviors of the dielectric elastomer are experimentallyinvestigated and it is noted that the impedance of the die lectric elastomer varies de pending on external forcesacting on it. Based on that concept, we propose the principle of a self-sensing actuator according to experimentalresult. In addition, a multi stacked actuator with self sensing capability is realized to validate its feasibility.Keywords: dielectric elastomer, self-sensing, actuator 1. INTRODUCTION During last decades, a great deal of researches on electroactive polymer actuators (EAPs) has been conductedwith remarkable progresses. Among them, dielectric elastomer actuator is one of the most prospectives because ofits large deformation and force, and cost eect iveness. 1 There are numerous dielectri c elastomers commerciallyavailable such as silicone, polyurethane, acrylic elastomer etc.