• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.108-117
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• 2003

Development of advanced restraint system challenges both restraint and automobile manufacturers to come up with proper airbag design to reduce occupant out-of-position related injury. The important component of the advanced restraint system is the multi stage inflator. The multi stage inflator can independently control two or more airbag inflation stages to maximize occupant protection. The objective of this research is to develop relationship between airbag inflation characteristics, the occupant positions and the airbag design variables. The tests are conducted using five kinds of inflators, two kinds of airbag cushion folding methods and two kinds of tear lines. In the case of inflator, the out-of-position tests are performed with a traditional inflator, a depowered inflator and a dual stage inflator. And the efficiency and injury mechanism are evaluated by analyzing the injury pulses and values. Using this relationship, airbag design guideline is established for airbag aggressivity thresholds and the risk of injury is identified according to occupant positions.

• International Journal of Quality Innovation
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• v.5 no.1
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• pp.68-84
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• 2004

The measured values of a same object should remain constant regardless of the object's position in the image. In other words, its measured values should not vary as its position in the image changes. However, lens' image distortion, heterogeneous light source, varied angle between the measuring apparatus and the object, and different surroundings where the testing is set up will all cause variation in the measurement of the object when the object's position in the image changes. This research attempts to compensate the machine vision image distortion caused by the object's position in the image by developing the compensation table. The compensation is accomplished by facilitating users to obtain the correcting object and serves the objective of improving the precision of measurement.

• Journal of Power Electronics
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• v.1 no.1
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• pp.1-8
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• 2001

The elimination of a pole sensor is desirable due to the low-cost requirement, the compactness, and the applied drives. This paper proposes the algorithm for the initial pole-position estimation of a surface permanent magnet linear synchronous motor (PM-LSM), which is carried out under the closed loop control without a pole sensor and is insensitive to the motor parameters. This algorithm is based on the principle that the initial pole position (IPP) is estimated by the trigonometric function of the two reference currents. The effectiveness of the proposed algorithm is confirmed by testing a surface PM-LSM with large disturbance, which result shows that IPP is well estimated within a satisfied moving-distance and a shorter estimation taken-time even if large disturbance such as cogging and friction is existed.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.249-253
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• 2004

This paper presents an implementation of position control system of Switched Reluctance Motor (SRM) using digital hysteresis controller. Although SRM possess several advantages including simple structure and high efficiency, the control drive system using power semiconductor device is required to drive this motor. The control drive system increases overall system cost. To overcome this problem and increase the application of SRM, it is needed to develope the servo drive system of SRM. So, the position control system of 1 Hp SRM is developed and evaluated by adaptive switching angle control. The position/speed response characteristics and voltage/current waveforms are presented to prove the capability of SRM for a servo drive application. Moreover, digital hysteresis current controller is developed and evaluated by experimental testing for the purpose of system developmental cost reduction.

• Journal of Power Electronics
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• v.10 no.4
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• pp.396-404
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• 2010

This paper presents simple schemes used to estimate the initial rotor position and the d- and q-axis inductances for effective Maximum Torque per Ampere (MTPA) operation in a wind-power system using an IPMSM (Interior Permanent Magnet Synchronous Machine). An IPMSM essentially requires an exact coordinate transformation and accurate inductance values to use a reluctance torque caused by the saliency characteristic. In the proposed high-frequency voltage testing method, there is no voltage drop caused by the resistance and the electromotive force. The initial rotor position and the inductance can be measured through an analysis of the stator current without turning the rotor. The experimental results are presented in order to illustrate the feasibility of the proposed method.

• Korean Journal of Digital Imaging in Medicine
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• v.11 no.1
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• pp.27-33
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• 2009

In this study, we compared the alteration of test positions according to various test equipments when testing shoulder joint superoinferior axial to estimate the clinical usefulness of tiltable standing detector. Our objectives were patients who visited our hospital. Among them we chose patients who were prescribed to get a shoulder axial test, again we selected 30 patients whose abduction is more than 90 degree.(2008. Nov.$\sim$2009 Jan.) With the patients cooperation, we used CR(Agfa, Belgium), fixed-detector(Canon, japan), Tiltable-detector(Philips, Netherlands). Tested with only one equipment(tiltable detector), and posed with the other two. We surveyed 5 inspectors and 30 patients, asking them to rate the convenience of test position. Also, we checked how long it takes to have the image appear on screen after testing with the equipment We provided a standard for an assessment of the image to an expert in bone radiology, an orthopedist and a radiologist with 5 years experience. When the patients were asked about the convenience of the equipments, 15 people(50%) answered CR is convenient and 14 people(46.7%) answered the Tilting detector is convenient, showing not much difference. However, when the inspectors were asked the same question, 4people(80%) out of 5 answered that the Tilting detector is more convenient The time test showed that CR takes 2 minutes and 50 seconds, the Fixed detector 1minute and 48 seconds andor had no distortion showing the shoulder joint space. However, even though the Fixed detector showed ac the Tilting detector takes 1 minute and 43 seconds to bring the image to the screen after the position. The results of the value of image taken by each equipment, CR and the Tilting detectromion, coracoid process, due to the unstable pose, they were quite distorted and scored poor in observing glenoid fossa. By this study, we can see that testing the shoulder joint superoinferior axial projection with a detector that has a tilting device would be more convenient than testing it with a CR.

• Advances in Automotive Engineering
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• v.1 no.1
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• pp.61-77
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• 2018

In this study, the effects of sitting position of the driver on the whiplash neck injury have been analyzed experimentally by using hybrid III series 50 percentile male crash test dummy. A testing platform consisting of vehicle ground, driver foot rest, driver seat and a 3-point seatbelt has been prepared. This testing platform and the instrumented crash test dummy are prepared for tests according to the Euro NCAP whiplash testing protocol. The prepared test set-up has been exposed to 3 different acceleration-time loading curves defined in the Euro NCAP whiplash testing protocol by performing sled tests. 9 different sled tests have been performed with the combinations of 3 different seating positions of the crash test dummy and 3 different acceleration-time loading curves. The sensor data obtained from the crash test dummy and high-speed videos taken are analyzed according to the injury assessments criteria defined in the Euro NCAP whiplash testing protocol and the criticality of the whiplash injury is defined. It is seen that the backset distance of the driver head with the headrest and the height difference of the top of the head of the driver with the headrest have a great importance on whiplash injuries.

• Physical Therapy Korea
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• v.3 no.1
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• pp.40-47
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• 1996

Body position is known to have an effect on vital capacity(VC). The purpose of this study was to examine effect on VC of posture, sex and smoking, and the difference between predicted and measured values of VC. VC was measured in the standing and the $30^{\circ}$ head-down position in 40 healthy subjects (20 men and 20 women) in a random order of testing. When subjects changed from standing to head-down position, this VC decreased by 19.9%. In both positions, VC changes in men were significantly larger than in women. No statistically significant difference was found in men who smoked. There was no difference between the predicted and measured values in men. But measured values were larger than predicted values in women. Because VC can decrease by 19.9% in the head-down position due to the effect of gravity, attention should be paid especially to patients who are placed in the head-down position for postural drainage since they already have a decreased VC.

• Journal of Auto-vehicle Safety Association
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• v.10 no.3
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• pp.32-37
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• 2018

Recently, the driver can be assisted by the advanced active safety devices such as ADAS from road traffic risks. With this system, driver and passenger may freed from can driving tasks or kept eyes on forward direction while on the road. Help from adoptive cruise control, auto parking and newly develped automated driving vehicles technologies, the driver positions will vary significantly from the current standard driver position during the travel time. On this hypothesis, the objective of this study is analyze the behavior and injuries of drivers in the event of frontal impact under these abnormal driver position. Based on the KNCAP frontal impact testing method, this simulation matrix was set-up with dummies of 5 th tile female Hybrid III dummy and 50 th tile male Hybrid III dummy. The small sedan type passenger car was modeled in this simulation. The series of simulation was performed to compare the injuries and behaviour of each dummy, varying the seating status and seat position of each dummy.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.7
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• pp.1156-1165
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• 1997

Complex modal testing is employed for the in-situ parameter identification of a four-axis active magnetic bearing system while the system is in operation. In the test, magnetic bearings are used as exciters as well as actuators for feedback control. The experimental results show that the directional frequency response function, which is properly defined in the complex domain, is a powerful tool for identification of bearing as well as modal parameters. It is also shown that the position and current stiffnesses can be accurately estimated using the relations between the measured forces, displacements, and currents.