Search

Absence seizures are caused by abnormal synchronized oscillations in the thalamocortical (TC) circuit, which result in widespread spike-and-wave discharges (SWDs) on electroencephalography (EEG) as well as impairment of consciousness. Thalamic reticular nucleus (TRN) and TC neurons are known to interact dynamically to generate TC circuitry oscillations during SWDs. Clinical studies have suggested the association of

The analgesic effect of alpha-2 adrenergic receptor (α2AR) agonists, which relieve chronic neuropathic pain, is highly variable among individuals. Here, we used a mouse model of spared nerve injury (SNI) to show that treatment time after the establishment of neuropathic pain was important for the variability in the analgesic efficacy of α2AR agonists, which was related to the activity of regulator of G-protein signaling protein 4 (RGS4). Intrathecal treatment with α2AR agonists, clonidine (0.1–1 nmol) or dexmedetomidine (0.3–1 nmol), relieved mechanical allodynia and thermal hyperalgesia on postoperative day (POD) 14, but their efficacy was weaker on POD28 and absent on POD56. The RGS4 level of plasma membrane was increased on POD56 compared to that on POD14. Moreover, in RGS4-deficient or RGS4 inhibitor (CCG50014)-treated mice, the analgesic effect of the α2AR agonists was conserved even on POD56. The increased plasma membrane RGS4 expression and the reduced level of active Gαi after clonidine injection on POD56 were completely restored by CCG50014. Higher doses of clonidine (10 nmol) and dexmedetomidine (3 nmol) relieved neuropathic pain on POD56 but were accompanied with serious side effects. Whereas, the coadministration of CCG50014 with clonidine (1 nmol) or dexmedetomidine (1 nmol) did not cause side effects. These findings demonstrated that SNI-induced increase in plasma membrane RGS4 expression was associated with low efficacy of α2AR agonists in a model of persistent, chronic neuropathic pain. Furthermore, α2AR agonist administration together with RGS4-targeted intervention represents a novel strategy for the treatment of neuropathic pain to overcome dose-limiting side effects.

This study suggests a relationship between two different types of magnetorheological dampers and the driving performance of the passenger vehicles such as ride quality and stability. One of the magnetorheological dampers has the two different bypass holes in the piston bobbin to achieve a relatively low damping force slope in the low piston velocity region. Without bypass holes, two cylindrical-type magnetorheological dampers have same dimensions (pole lengths, piston radius, and coil size). To enhance the ride quality of the passenger vehicle, the damping force slope of the magnetorheological damper with bypass holes is more gradual than that of the magnetorheological damper without bypass holes. On the basis of the damping force model, three vehicle types with two working modes (soft and hard) are formulated. Driving performance indexes, such as vertical acceleration of the sprung mass and tire deflection, are evaluated in frequency domains under two random road conditions. A comparative study is conducted to prove the effectiveness of the magnetorheological damper with bypass holes through simulation.

The existing heat pipe applied to a LED headlamp has a large size although it has only small area of contact. Therefore, it is difficult to achieve a harmonious radiation of heat along with the difficulty in attaching the LED due to its large volume. This study proposed a plate heat pipe to solve the aforementioned problems. Through the study, the effects of the thickness and acetone filling rate on the heat radiation effects of a plate heat pipe at room temperature and vehicle driving environment were confirmed along with comparison with the heat radiation effects of the existing copper heat pipe. The heat radiation effects were checked by attaching a thermocouple to the evaporator, adiabatic section and condenser of the LED. As the results of the experiment, it was found that a temperature below 120oC, which is the allowable temperature to guarantee the performance of the LED, is maintained. In addition, as the results of comparison of radiation of heat, it was confirmed that the plate heat pipe with a thickness of 2 mm and 20% filled with acetone has a better performance than the existing copper heat pipe.

Fibrillar aggregates of amyloid-β (Aβ) are the main component of plaques lining the cerebrovasculature in cerebral amyloid angiopathy. As the predominant Aβ isoform in vascular deposits, Aβ40 is a valuable target in cerebral amyloid angiopathy research. However, the slow process of Aβ40 aggregation in vitro is a bottleneck in the search for Aβ-targeting molecules. In this study, we sought a method to accelerate the aggregation of Aβ40 in vitro, to improve experimental screening procedures. We evaluated the aggregating ability of bicine, a biological buffer, using various in vitro methods. Our data suggest that bicine promotes the aggregation of Aβ40 with high speed and reproducibility, yielding a mixture of aggregates with significant β-sheet-rich fibril formation and toxicity.

The analgesic effect of alpha-2 adrenergic receptor (α

Mitochondrial dysfunction is associated with neuronal damage in Huntington's disease (HD), but the precise mechanism of mitochondria-dependent pathogenesis is not understood yet. Herein, we found that colocalization of XIAP and p53 was prominent in the cytosolic compartments of normal subjects but reduced in HD patients and HD transgenic animal models. Overexpression of mutant Huntingtin (mHTT) reduced XIAP levels and elevated mitochondrial localization of p53 in striatal cells in vitro and in vivo. Interestingly, XIAP interacted directly with the C-terminal domain of p53 and decreased its stability via autophagy. Overexpression of XIAP prevented mitochondrially targeted-p53 (Mito-p53)-induced mitochondrial oxidative stress and striatal cell death, whereas, knockdown of XIAP exacerbated Mito-p53-induced neuronal damage in vitro. In vivo transduction of AAV-shRNA XIAP in the dorsal striatum induced rapid onset of disease and reduced the lifespan of HD transgenic (N171-82Q) mice compared to WT littermate mice. XIAP dysfunction led to ultrastructural changes of the mitochondrial cristae and nucleus morphology in striatal cells. Knockdown of XIAP exacerbated neuropathology and motor dysfunctions in N171-82Q mice. In contrast, XIAP overexpression improved neuropathology and motor behaviors in both AAV-mHTT-transduced mice and N171-82Q mice. Our data provides a molecular and pathological mechanism that deregulation of XIAP triggers mitochondria dysfunction and other neuropathological processes via the neurotoxic effect of p53 in HD. Together, the XIAP-p53 pathway is a novel pathological marker and can be a therapeutic target for improving the symptoms in HD.

Human ribosomal protein S3 (hRpS3) is a component of the 40S ribosomal subunit that associated in protein synthesis. hRpS3 has additional ribosomal functions such as DNA repair, transcription, metastasis, and apoptosis via interaction with numerous signaling molecules and has different modifications. Cyclin-dependent kinases (CDKs) are heterodimeric serine/threonine protein kinases that regulate cell cycle progression. Among its members, the Cdk1-cyclin B complex is known to control cell progression in the G2/M phase, while Cdk2-cyclin E/A complexes function in G1/S and S/G2 transition. In our previous study, we observed interaction between hRpS3 and Cdk1. The present study investigated the interaction between hRpS3 and Cdk2. Cdk2 phosphorylated hRps3 at amino acid residues S6 and T221 during the S-phase. Furthermore, hRpS3 knockdown delayed cell cycle progression by modulating the expression of cell cycle-related proteins, including cyclin B1 and cyclin E1. These findings suggest that hRpS3 is involved in Cdk2-mediated cell cycle regulation.

Human prostaglandin E2 receptor 4 (EP4) is one of the four subtypes of prostaglandin E2 (PGE2) receptors and belongs to the rhodopsin-type G protein-coupled receptor (GPCR) family. Particularly, EP4 is expressed in various cancer cells and is involved in cancer-cell proliferation by a G protein signaling cascade. To prepare an active form of EP4 for biochemical characterization and pharmaceutical application, this study designed a recombinant protein comprising human EP4 fused to the P9 protein (a major envelope protein of phi6 phage) and overexpressed the P9-EP4 fusion protein in the membrane fraction of E. coli. The solubilized P9-EP4 with sarkosyl (a strong anionic detergent) was purified by affinity chromatography. The purified protein was stabilized with amphiphilic polymers derived from poly-γ-glutamate. The polymer-stabilized P9-EP4 showed specific interaction with the alpha subunits of Gs or Gi proteins, and a high content of α-helical structure by a circular dichroism spectroscopy. Furthermore, the polymer-stabilized P9-EP4 showed strong heat resistance compared with P9-EP4 in detergents. The functional preparation of EP4 and its stabilization with amphiphilic polymers could facilitate both the biochemical characterization and pharmacological applications targeting EP4., Highlights • Prostaglandin E2 receptor 4 (EP4) was overexpressed as P9-fusion protein in E. coli. • The APG-stabilized P9-EP4 showed specific interaction with the alpha subunits and its ligands. • The APG-stabilized P9-EP4 showed strong heat resistance compared with P9-EP4 in detergents. • The binding kinetics of P9-EP4 with both antagonists and agonists were analyzed.

DNA nanostructures have become an important and powerful tool for studying protein function over the last 5 years. One of the challenges, though, has been the development of universal methods for patterning protein complexes on DNA nanostructures. Herein, we present a new approach for labeling DNA nanostructures by functionalizing them with a GFP nanobody. We demonstrate the ability to precisely control protein attachment via our nanobody linker using two enzymatic model systems, namely adenylyl cyclase activity and myosin motility. Finally, we test the power of this attachment method by patterning unpurified, endogenously expressed Arp2/3 protein complex from cell lysate. By bridging DNA nanostructures with a fluorescent protein ubiquitous throughout cell and developmental biology and protein biochemistry, this approach significantly streamlines the application of DNA nanostructures as a programmable scaffold in biological studies.

In the present study, Lumbar Support, according to 2 types of methods was mounted on the driver’s seat of a passenger car for a comparative analysis of performance. For experiments, the amounts of swelling upon operation and of the deflection as a function of changes in the load were obtained with emphasis on a static load compression test, an elasticity restoration test, and the H/point. Also, actual pressure distributions produced between the human body and the seat were measured and analyzed. Following this, the performance difference for the two types of lumbar support was analyzed and the ergonomic effects of the characteristics were discussed.

In this study was conducted with focus on the change in vibration characteristics in the rail to analyze the noise produced in the rail upon operation of slide mechanism in power seat for vehicles. Preferentially, the motor rpm was simultaneously measured about operating noise, vibration as operating into direction of forward and backward with the slide mechanism. And, modal test was conducted according to operation position of the seat rail, through which overall analysis was conducted for the effects of vibration characteristics of the rail on operating to noise. According to the results, it could be seen that resonance occurred between the 2nd natural frequency generated on the left upper rail and the 3rd order of motor rotation to affect the operating noise.

This study experimentally investigated the friction noise in the lead screw system. The mechanism involved in the friction noise was analyzed on basis of the mode-coupling characteristics. Therefore, the frequency separation between two modes near the squeak frequency was traced with the location of nut. It was found that the friction noise of the lead screw was generated only at the nut location where the frequencies of the axial and torsion modes were met. It indicated that the friction noise in the lead screw system was caused by the mode coupling between the torsion and axial modes.

Established fear memory becomes vulnerable to disruption after memory retrieval and extinction; this labile state is critical for inhibiting the return of fear memory. However, the labile state has a very narrow time window after retrieval, and underlying molecular mechanisms are not well known. To that end, we isolated the hippocampus immediately after fear memory retrieval and performed proteomics. We identified Neurobeachin (NBEA), an autism-related regulator of synaptic protein trafficking, to be upregulated after contextual fear memory retrieval. NBEA protein expression was rapid and transient after fear memory retrieval at the synapse. Nbea mRNA was enriched at the synapses, and the rapid induction of NBEA expression was blocked by inhibition of the mammalian target of rapamycin (mTOR)-dependent signaling pathway. Mice with cornu ammonis 1 (CA1)-specific Nbea shRNA knockdown showed normal fear acquisition and contextual fear memory but impaired extinction, suggesting an important role of Nbea in fear memory extinction processes. Consistently, Nbea heterozygotes showed normal fear acquisition and fear memory recall but showed impairment in extinction. Our data suggest that NBEA is necessary either for induction of memory lability or for the physiological process of memory extinction.

This study investigates the effects of the dynamic characteristics of the lead screw on the operating noise of the seat adjuster through experiments and numerical analysis. The dynamic characteristics of the lead screw were determined through a modal test in three boundary conditions, namely free-free, clamped-pinned, and the change in position of the gearbox on the lead screw. The operating noise was measured using an experimental device that minimized elements other than the lead screw. Lastly, the modal test results of the leadscrew were applied to the mathematical model, and numerical analysis was carried out. It was found that the cause of resonance noise and vibration instability of the lead screw was the incomplete restraint of the front bracket.

LK-3, an amphipathic dimeric peptide linked by two disulfide bonds, and related isomeric bundles were synthesized, and their cell penetrating abilities were investigated. The measurements using size exclusion chromatography and dynamic light scattering show that LK-3 and its isomers form cell penetrating oligomers. Calculations, performed for various types of peptide isomers, elucidate a strong correlation between the amphipathic character of dimers and cell penetration ability. The results suggest that the amphipathicities of LK-3 and related bundle dimers are responsible for their oligomerization propensities which in turn determine their cell penetrating abilities. The observations made in this study provide detailed information about the mechanism of cell uptake of LK-3 and suggest a plausible insight of the early stage of nanoparticle formation of the cell penetrating amphipathic peptides., LK-3, an amphipathic dimeric peptide, shows good cell penetrating ability. Calculations show that the amphipathicity of LK-3 is responsible for its oligomerization and the cell penetrating abilities.

Centers for Neuro-Medicine, Neuroscience and Theragnosis, Korea Institute of Science and Technology (KIST), Seoul 136-791, Republic of Korea. *E-mail: yskim@bio.kist.re.kr Biological Chemistry Program, Korea University of Science and Technology (UST), Daejeon 305-350, Republic of Korea Department of Biochemistry and Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea Department of Life Sciences, Korea University, Seoul 136-701, Republic of Korea kYonsei University Wonju College of Medicine, Gangwon-do 220-701, Republic of Korea Molecular Imaging Research Center, Korea Institute of Radiological &Medical Sciences (KIRAMS), Seoul 139-706, Republic of Korea Received October 30, 2014, Accepted January 14, 2015, Published online April 27, 2015

The regulator of G-protein signaling protein type 4 (RGS4) accelerates the guanosine triphosphatase activity of G(αi) and G(αo), resulting in the inactivation of G-protein-coupled receptor signaling. An opioid receptor (OR), a G(αi)-coupled receptor, plays an important role in pain modulation in the central nervous system. In this study, we examined whether (1) spinal RGS4 affected nociceptive responses in the formalin pain test, (2) this RGS4-mediated effect was involved in OR activation, and (3) the µ-OR agonist-induced antinociceptive effect was modified by RGS4 modulation.Formalin (1%, 20 µL) was injected subcutaneously into the right hindpaws of male 129S4/SvJae×C57BL/6J (RGS4(+/+) or RGS4(-/-)) mice, and the licking responses were counted for 40 minutes. The time periods (seconds) spent licking the injected paw during 0 to 10 minutes (early phase) and 10 to 40 minutes (late phase) were measured as indicators of acute nociception and inflammatory pain response, respectively. An RGS4 inhibitor, CCG50014, and/or a µ-OR agonist, [D-Ala², N-MePhe⁴, Gly-ol]-enkephalin (DAMGO), were intrathecally injected 5 minutes before the formalin injection. A nonselective OR antagonist, naloxone, was intraperitoneally injected 30 minutes before the CCG50014 injection.Mice that received the formalin injection exhibited typical biphasic nociceptive behaviors. The nociceptive responses in RGS4-knockout mice were significantly decreased during the late phase but not during the early phase. Similarly, intrathecally administered CCG50014 (10, 30, or 100 nmol) attenuated the nociceptive responses during the late phase in a dose-dependent manner. The antinociceptive effect of the RGS4 inhibitor was totally blocked by naloxone (5 mg/kg). In contrast, intrathecal injection of DAMGO achieved a dose-dependent reduction of the nociceptive responses at the early and late phases. This analgesic effect of DAMGO was significantly enhanced by the genetic depletion of RGS4 or by coadministration of CCG50014 (10 nmol).These findings demonstrated that spinal RGS4 inhibited the endogenous or exogenous OR-mediated antinociceptive effect in the formalin pain test. Thus, the inhibition of RGS4 activity can enhance OR agonist-induced analgesia. The enhancement of OR agonist-induced analgesia by coadministration of the RGS4 inhibitor suggests a new therapeutic strategy for the management of inflammatory pain.

An analytical model was developed by Sim to calculate the two-phase damping ratio for upward two-phase flow perpendicular to horizontal tube bundles. To verify the model, the present experiment is performed with a typical normal square array of cylinders subjected to the two-phase flow of air-water in the tube bundles. The diameter of cylinder is 18mm and the pitch ratio to diameter is 1.35. Using a pressure transducer and data acquisition system, pressure loss along the flow direction in the tube bundles is measured to evaluate the two-phase Euler number and the two-phase friction multiplier. The drag force along the flow direction on a tube is measured to calculate the drag coefficient and the two-phase damping ratio. The experimental results of the two-phase damping ratios are compared with the analytical results given by Sim’s model for homogeneous two-phase flow. It was found that, as increasing the mass flux, the drag force and the drag coefficients given by experimental test are close to the results calculated by the homogeneous model. As a result, the damping ratio can be evaluated by the homogeneous model for bubbly flow of sufficiently large mass flux.

The changes in vibration, sound, and sound quality with changes in the driving voltage of a power seat motor from 12.5 to 14.5 V were measured and analyzed, which was used in real vehicles. BSR (buzz, squeak, rattle), which occurs for the power seat mechanism during sliding operation, was also evaluated. In addition, the results were expressed in terms of sound quality metrics, which measure the RPM change and sound level versus voltage to analyze their statistical correlation. Furthermore, vibration measurement and analysis were conducted simultaneously to determine the noisiest conditions and the source of the noise. The changes in RPM and voltage of a motor, in addition to vibration and noise, were measured at the same time to determine how noise, RPM, and voltage are interrelated.

This paper is a study on cutting analysis of three-layer laminated plates after machining. The outer layers of the milled object were stainless steel and Cr-Mo steel plates, sandwiching a middle layer of aluminum plate. As for the tool, the cylindrical cutter used for groove making was chosen as the model. Analysis was performed in two-dimensional plane mode. As for analysis results, the change in chip shape according to cutting tool travel distance was shown in a series of diagrams, and the cutting temperature, strain rate and required cutting force, etc., were found. It is expected that these results can be utilized in machining processes and work conditions for the machining of multi-layer structures made of layers of different materials.

시트 프레임의 연구 개발이 활발하게 진행됨에 따라 본 연구에서는 고장력강판으로 제작된 시트 프레임의 전변형량을 실험과 해석을 통하여 고찰하였다. SPFC 980 t=2mm 고장력강판으로 된 시트 프레임을 반복피로 내구 시험기를 이용하여 전변형량 실험을 한 후, 동일한 조건으로 시뮬레이션하여 전변형량을 해석하였다. 실험과 해석 결과 값을 비교 분석한 후 그 값을 토대로 SPFC 780 t=2mm와 SPFC 780 t=1.5mm으로 된 시트 프레임 모델들의 구조적 안전성을 유한 요소 해석으로서 조사하였고 본 연구 결과를 통하여 어떤 모델이 상용화하는데 더 적합한지를 알 수 있었다. 【As research development of seat frame is being studied actively, the total deformation of seat frame made of high tension steel plate(HTSP) is examined in this study. The seat frame made of SPFC 980 t=2mm with HTSP is tested to obtain total deformation through repeated fatigue durability tester and total deformation is analyzed by simulation under the same condition as experiment. After analyzing by comparing the results of experiment and analysis, structural stabilities of seat frame models with SPFC 780 t=2mm and SPFC 780 t=1.5mm are investigated by FEM analysis on the basis of these results. And it is considered that which model is more suitable at commercial use can be found through this study result.】

Objectives: Since the riding comfort upon seating is determined according to the driving environment or the driver’s preference, objective evaluations are accompanied by many constraints. Methods/Statistical Analysis: Variations in stiffness distribution of the seat cushion were analyzed by using body pressure distribution. First, to identify loaddeflection characteristics of the seat cushion, static load tests were conducted and stiffness characteristics as a function of load were affirmed by application of quadratic spline interpolation method. And, body pressure distribution of the male subject produced upon seating in the cushion was measured under actual vehicle conditions. Findings: Variations in stiffness distribution of the seat cushion produced when a driver comes aboard a vehicle, and the following conclusions could be obtained. First, by conducting static load tests for the seat cushion to obtain load-deflection curves, deflection characteristics per load point were identified. Second, through quadratic function for the load-deflection curves derived from static load tests, stiffness distributions were derived. Stiffness characteristics were continuously varied as a function of load distribution applied to the seat cushion, which was analyzed to have an effect on stiffness distribution as a function of body pressure distribution for the driver. Third, based on body pressure distribution data for the male subject and load-deflection curves for the seat cushion, variations in stiffness of the seat cushion were analyzed as a function of body pressure distribution. As a result, the extent of hardness felt by the human body was greater for the right side even if body pressure of the male subject was shown to be larger in the left-side region. Application/Improvements: Characteristics of seat stiffness distribution as a function of body pressure distribution which were derived in the present study are considered to be utilized for pad development of car seat.

In this study, the vibration and noise for the cushion frame that directly contacts the driver of the car are investigated. The friction noise from the seat track generating the largest noise is measured and analyzed. Also, vibration measurement and analysis are performed in parallel to locate the position from where the noise is generated. In the next stage, the RPM of motor and the current changes during motor driving are measured. The vibration and noise generated during motor running are also measured and analyzed to examine the interaction between noise from the track and load on the motor. The vibration and noise analysis results are expressed using FFT analysis, octave analysis, spectrum contour map analysis, and sound visualization.

A solenoid pump is a reciprocating piston pump that moves linearly by the aid of a piston cylinder attached at the linear motor axis which carries out a reciprocating motion. Generally, a solenoid pump is a pump utilizing a magnetic plunger of magnetic substance and an electric induction coil. A solenoid pump model for the hydraulic pressure that can control bi-directionally and can generate a high pressure is proposed in this study. The design parameters for the parts of the solenoid pump used for hydraulic pressure are studied using a numerical analysis method. After selecting an adequate solenoid model, the magnetic force and magnetic density on the model are estimated by electromagnetic force analysis. Based on the obtained magnetic force and magnetic density, a structural analysis of the model is performed. Also, design parameters are obtained for the robust design by vibration mode analysis to avoid resonance effect on the key parts of the system. The results of the vibration mode analysis and FFT analysis are proposed in the design of new products.

The purpose of this study is to investigate cooling performance of high power LEDs from 100 to 200 W class by using a jet impingement cooling module. The numerical analysis of forced convection cooling inside cooling module is carried out using a multi-purpose CFD software, FLUENT 6.3. In the experiments, the LED cooling system consists of jet impingement module, heat exchanger, water reservoir, and pump. In the present study, the cooling performance of jet impingement cooling module is investigated to determine the effect of the heat sink types on the impinging surface, the space and length of fins. Numerical and experimental studies show the reasonable agreement of LED metal PCB temperature between those results and give the optimized design parameters such as the space of fin and the length of fin. Also, the pin fin type of heat sink is found to be more efficient than the plate type heat sink in jet impingement cooling.

Automotive seat recliner has the function to control the angle at the back of chair and has the relation close to the safety of seat. Therefore each of parts constituting the recliner is important and the recliner housing to protect these parts from various dynamic loads is also important. In this study, the recliner housing with t=3mm which is made of high tension steel plate(SPFC 980) is applied to actual automotive seat. The deformation is investigated through the durability tester. Deformation and equivalent stress are also analyzed by simulation analysis under the same condition with experiment. After recliners with thicknesses of 1mm and 2mm are modeled by bases of experimental and analysis values, deformation and equivalent stress are investigated through structural analysis.

This study proposes an structure that fixes the shielding device to two parts of the board by its two arranged clips. Said structure evenly distributes its loading/unloading load of the board and maintains the flatness of soldering area of the board. The structure of this study comprises a base part fixed to a printed circuit board and a clip part fixing a side wall of a shield can to the board, wherein the clip part is constituted with two clips fixable to two part of the shield can. Also, the structure of this study comprises a dented groove in order to easily solder the base part of clips and the printed circuit board. A mechanism is established and a design parameter was determined by a structure analysis and a vibration mode analysis. A single purpose machine for the production of the product was developed, the final workpiece was produced and the measuring-data and the computered-data was compared and reviewed. Key Words : Electromagnetic wave, Shield can, Clip, EMI: Electro Magnetic Interference, Cell phone

Objectives: Recent trends show an increase in driving by the elderly and most of them drive with a poor posture. In this study, not only the tests for body pressure but also the tests to identify characteristics of the seat itself were conducted. Methods/Statistical Analysis: Static load tests were conducted first to derive the seat-inherent characteristics such as deflection and hardness, etc. of the seat cushion as a function of loads for the automotive seat, and measurement tests for body pressure were conducted to secure body pressure data of the elderly. Combining the above two test results, final hardness values were obtained through which seat cushion pattern models having 8-hardness distributions could be derived. Findings: As a result, curves and functional equation for the two variables were derived through deflection as a function of measured loads. Also, hardness values at each point of the cushion could be found from the slopes of the curves mentioned, with the appearance of the phenomenon where the slope showed a steep increase in a particular region. This was affirmed to have occurred due to a difference in thicknesses of the cushion. Secondly, concentrated regions of body pressure per subject were affirmed and analyzed in the body pressure tests. By combining two test results, a total of 11 seat cushion pattern models could be derived, of which pattern analyses were conducted for 3 types observed with many personnel. Improvements/Applications: When the cushions are produced on the basis of the above pattern, it is considered possible to more ideally distribute the weight and to improve comfort upon seating compared with the commercial cushions.

Background/Objectives: Recently, problems of noise produced in the vehicle body are emerging. The apparatus for discharging exhaust gas produced after combustion should suitably absorb vibration and noise from the engine. Methods/ Statistical Analysis: The workpiece was used AISI 316. Characteristics shown under an internal pressure of 8~12MPa and a die speed of 9~235mm/sec were observed. With an assumption that all external conditions were the same, internal pressure due to forming-oil and speeds of die and punch were controlled. Meshes were generated in a total element number of 9,282. For plastic finite elements analysis, DEFORM 2D as the specialized plasticity code of US was employed. Findings: It was shown to be affected by internal pressures rather than by the speeds of the punch and die. Crease was affirmed to be produced in a stable manner from the minimum internal pressure of 10MPa. The gap between die and crease was shown to be smaller, the higher the pressure. And it was shown to be smaller as the speed was increased. Although formability is improved with an increase in the speeds of the punch and die, produced equivalent stresses were determined to be increased. The equivalent stress produced in the crease did not exhibit a large amount of variation as a function of internal pressure and die speed. However, as the center part of the bellows was approached, smaller equivalent stresses were observed, and while larger stresses were produced, the closer it was to the punch. Similar tendency was also shown for the load acting upon die. Therefore, it appears that speed of punch and acting load should be carefully considered in production of bellows. Application/Improvements: Characteristics of plasticity according to each case were identified, and parameters were secured allowing a comparative analysis with experimental data through future experiments.

Background/Objectives: A representative tool end mill, and predictive studies on tool wear and tool life are in urgent need since the number of products requiring high-precision processing has being increasing recently. Method/Statistical Analysis: The workpiece had a size of 20mm in length, 20mm in width, and 5mm in thickness. For the tool with the outside diameter of 8mm, the radial rake angle of 5°, and the helix angle of 20°. Processing involved oblique processing at an angle of 5° so that the depth was increased as the transfer progressed. Revolution of the tool was 600RPM with the feed-rate being set at 100mm/min. Findings: Upon initial processing, plastic deformation can be seen to occur in a center part of the end mill also, as the depth was increased while almost no initial plasticity occurred in the center part. The maximum temperature occurs at the blade tip of tool edge part that was cut the deepest, and a high temperature of about 1334.5° C was produced. Therefore, work hardening is expected to occur upon processing due to such high temperature. After the formation of chips by processing flow, rapid cooling may be observed. While similar cutting forces for all of x, y, and z axes are acting initially, those for the x-axis and y-axis can be seen to be drastically increased in a vertical direction up to about 18kN after rotation by about 900°, despite the fact that almost no cutting force is applied. The reason is considered to be application of severe vertical loads so as to act as a compressive stress for the tool as the depth of the end mill is increased in oblique plane processing. Application/Improvements: Severe concentrated loads occurred at the blade tip of tool edge so that a shivering phenomenon was considered to occur. This result will be used as the basic data upon product processing.