• Journal of Advanced Marine Engineering and Technology
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• v.26 no.5
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• pp.544-553
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• 2002

The recent amount of container freight continuously has been increased, but the low efficiency of container crane causes jamming frequently in transportation and cargo handling at port. It is required that the working velocity and safety are improved by control of moving the trolley as quick as possible without large overshoot and any residual swing motion of container at the destination. In this paper, a LQ controller for a container crane is proposed to accomplish an optimal design of improved control system for minimizing the swing motion at destination. In this scheme a mathematical model for the system is obtained in state space form. Finally, the effectiveness of the proposed controller is verified through computer simulation.

• Journal of Chest Surgery
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• v.19 no.4
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• pp.715-721
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• 1986

14 cases of pulmonary aspergillosis were managed surgically over a 6 year period in the Dept. of Thoracic Surgery Inje Medical College, Paik Hospital were reviewed. 1. Male, female ratio was 9:5 male predominant and 2,3,4 decade were prevalent. 2. The most prevalent chief complaint was hemoptysis, 9 cases [63%] and other symptoms were chronic productive cough 4 cases. 3. Preoperative diagnostic accuracy ratio was 0.21 [3 cases only]. 4. Right upper lobe was most common involving site, 7 cases [5[%], 13 lobectomy and 2 segmentectomy were performed. 5. Pathological underlying diseases were pulmonary tuberculosis 8 cases [57%], bronchiectasis and lung abscess was 1 case, no underlying disease were 4 cases. 6. One major postoperative complication was symptomatic residual dead space which was managed by thoracoplasty.

• Geotechnical Engineering
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• v.8 no.4
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• pp.51-66
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• 1992

As the scale of public works get recently larger and diversified. the construction of retain- ing walls is required for the effective use of land. In the design of the retaining wall, the reliability and fitness of the retaining wall itself are regarded prudently although there is a tendency to ignore the importance of backfill. In this study, the experiments under various conditions such as repetition-continuity-load, roller-press load, and working space of backfill, are carried out using a model retaining wall similar to the real system. The experimental roes tilts are interpreted theoretically, Using a computer program, the experimental results are analyzed and compared with other theoretical wonts.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.5
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• pp.240-246
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• 2014

A fault detector was developed for heat exchangers of a hybrid heat pump (HP) for household. The proposed detector can be applied directly to raw operating data. It is to monitor a tracking error between a measured saturation temperature and its state observer. The observer was estimated from a state-space model simulating dynamics of a heat exchanger. The real hybrid HP was substituted with a dynamic simulator that implemented two-phased heat transfer and was validated by experimental data. And artificial fault data were generated using the simulator. Diagnosing the data showed the following. The residual calculated from the state observer error shows a relatively robust consistency with respect fouling level. The fault detector is practically useful because it detects a threshold fouling beyond which the performance starts to deteriorate significantly.

• Geotechnical Engineering
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• v.2 no.1
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• pp.7-14
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• 1986

The structure of the collapsible soils, such as decomposed granite soil and loess, were examined by the odeometer test, SEM & XES analysis and static & cyclic triaxial test, and hove this structure have influences upon the collapsible behaviour under static and cyclic load was investigated. The study results obtained are as follows; 1. The macropores space of decomposed granite soil (rd=1.50g/cm3) and loess (rd=1.43g/cm3) used in this test were well developed, and showed the behaviour of collapsible soil. 2. Collapsible soil has high resistance on the strain under natural moisture content, however, the resistance on the strain was sharply decreased by the absorption and increasing load since its special structure was destructed. 3. Under the static load, the strain of collapsible soil was high by the viscous flow of the cyclic bonds with time lapse, but Infer the cyclic load, the strain of collapsible soil was low since the tinge needed to destruct the bonding force of clay was not enough. 4. The understanding about the cyclic behaviour of collapsible soil may be helpful to predict the elastic & residual strain of the foundations by the earthquake together with the damage by the additional failure.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.11a
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• pp.22-28
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• 2000

The fiber reinforced composite materials is widely used in aircraft, space structures and robot arms because of high specific strength and high specific modulus. The on-line cure monitoring during the cure process of the composite materials has become an important research area for the better quality and productivity. In this paper, the dielectric circuit of the wheatstone bridge type for measuring the dissipation factor was designed and manufactured. Also, the dielectric sensor for the cure monitoring of the high temperature composites was developed. The residual thermal stresses of the dielectric sensor were analyzed by the finite element method and its dielectric characteristics under high temperature were evaluated. The on-line cure monitoring of the BMI resin was performed using the wheatstone bridge type circuit and developed high-temperature dielectric sensor.

• Journal of Auto-vehicle Safety Association
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• v.12 no.1
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• pp.39-45
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• 2020

The express/intercity bus models have been developing for wheelchair users to provide the preferable long-distance travels by the Korean government research. In the previous studies, evaluation method was set up for the wheelchair users' safety and the study for wheelchair occupants' safety was performed under various crash loadings mimic to real accidents, frontal crash, side impact and rollover, etc. This study was focused on the evaluation of occupant behaviors and injuries (head and chest) during vehicle impact loading cases in order to ensure the safety of wheelchair passengers in the bus. The occupant response and belt loading data during the sled FE simulation were compared with those of the sled test. The simulation results showed overall safety tolerances of wheelchair occupants under the severe frontal deceleration, side impact loading based on the FMVSS 214 configuration and bus rollover loading.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.3
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• pp.156-165
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• 2005

A new heuristic algorithm for the heterogeneous single container loading problem is proposed in this paper, This algorithm fills empty spaces with the homogeneous load-blocks of identically oriented boxes and splits residual space into three sub spaces starting with an empty container. An initial loading pattern is built by applying this approach recursively until all boxes are exhausted or no empty spaces are left. In order to generate alternative loading patterns, the load-blocks of pattern determining spaces are replaced with the alternatives that were generated on determining the load-blocks. An improvement algorithm compares these alternatives with the initial pattern to find improved one. Numerical experiments with 715 test cases show the good performance of this new algorithm, above all for problems with strongly heterogeneous boxes.

• Journal of Hydrospace Technology
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• v.1 no.1
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• pp.75-88
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• 1995

Auto-Pilot System uses heading angle information via the position sensor and the rudder device to control the ship's direction. Most of the control logics are composed of the state estimation and control algorithms assuming that the measurement device and the actuator have no fault except the measurement noise. But such asumptions could bring the danger in real situation. For example, if the heading angle measuring device is out of order the control action based on those false position information could bring serious safety problem. In this study, the control system including improved method for processing the position information is applied to the Auto-Pilot System. To show the difference between general state estimator and F.D.F., BJDFs for the sensor and the actuator failure detection are designed and the performance are tested. And it is shown that bias error in sensor could be detected by state-augmented estimator. So the residual confined in the 2-dimension in the presence of the sensor failure could be unidirectional in output space and bias sensor error is much easier to be detected.

• Communications for Statistical Applications and Methods
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• v.26 no.4
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• pp.337-346
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• 2019

This paper discusses a method for obtaining nonnegative estimates for variance components in a random effects model. A variance component should be positive by definition. Nevertheless, estimates of variance components are sometimes given as negative values, which is not desirable. The proposed method is based on two basic ideas. One is the identification of the orthogonal vector subspaces according to factors and the other is to ascertain the projection in each orthogonal vector subspace. Hence, an observation vector can be denoted by the sum of projections. The method suggested here always produces nonnegative estimates using projections. Hartley's synthesis is used for the calculation of expected values of quadratic forms. It also discusses how to set up a residual model for each projection.