• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.635-638
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• 2000

It is necessary to work on a vertical plane of workpiece in order to produce a large structure like a ship. These works can be automated by using the robot with permanent magnet wheels. We developed the permanent magnet wheel which can be used by a mobile robot and easily detached. We enhanced an adhesive power by restricting the occurrence direction of magnetic flow. And we also developed a method which weakens adhesive magnetic force by changing magnetic flow with metal pins. We used the load cell and the gaussmeter to measure the characteristics of the adhesive force and magnetic force. We obtained the result that the adhesive power is reduced to 1/3 of normal state by using 4 inducing pins.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.6
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• pp.1141-1149
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• 2007

This paper describes two major techniques; image processing and gas vent insert and rejection control, for efficient gas vent exchange and holes detecting on the shoes mold. The key idea is to detect holes on the mold to select which holes to insert and to reject automatically guide center of hole's position. This allows us to save labor time while minimizing defective rate of PU shoes mold forming and production costs for gas vent exchange such as insertion and rejection.. Our experimental results have demonstrated that the hole's detection and gasvent exchange mechanism are more efficient and provide accurate mechanism to mitigate risks of vent injection/rejection failures.

• Journal of Animal Environmental Science
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• v.6 no.2
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• pp.105-112
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• 2000

The objective of this study was to determine the teat locations and to develop a teat cup handling system operated by a robot. The results of this study were summarized as follows: 1. The teat cup attaching and detaching operation system developed in this study consists of a control computer, a five-dimensional robot(PERFORMER-MK2), a DC servo gripper, a robot controller, two CCD-cameras (WV-vp410), an image grabber board(DT3153), a model cow, and a teat cup unit. 2. The coordinates of teat locations were measured by a stereo image processing unit. The error ranges of teats coordinates measured were (x, y, z) = (0.83, 1.95, 0.81) mm. When those were transferred into the Robot Coordinate System(RCS) coordinate, the total error ranges measured were x = 0.9 mm, y = 2.0 mm, z = 0.9 mm. 3. The rates of success of teat cup attaching and detaching operation by a robot system were 91.5% on average; the operation time needed were 27.8 sec. Total working hours for the teat cup handling including image processing were 86.1 sec.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.4
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• pp.435-440
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• 2012

Purpose: The purpose of this study is developing the dot sight with a $2{\times}$ magnification. Methods: To magnify the target when we see the far through the non-magnified dot sight, we develop the new optical device which is detachable to the non-magnified dot sight. A new optical device is designed to facilitate the transition of an existing non-magnification ($1{\times}$) dot sight to the $2{\times}$ magnification dot sight. Results: We could design and fabricate the $2{\times}$ afocal optical system which is detachable to the non-magnified dot sight and be composed by a pair of doublet. When the system developed in this study was used, we could aim the external target by twice magnification, so we could further improve the accuracy of aim. Conclusions: We could design and manufacture the $2{\times}$ afocal optical system which can be detachable to the non-magnified dot sight. With the results, we could aim the external target by twice magnification, so we could further improve the accuracy of aim.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.2
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• pp.173-180
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• 2021

Purpose: The purpose of this study was to evaluate the retentive characteristics of the additional attachments used with implant bar attachment under repeated insertion/removal cycles. Materials and methods: The newly developed attachment and the commercially available attachment were investigated: ADD-Lock (AL), Locator blue (LB). Two fixtures were placed parallel to each other on the custom lower mounting, and patrix of each attachment was fixed to the fixture. Also, the matrix of each attachment was placed on the opposing upper mounting. A universal testing machine was used to measure the retentive force during initial, 100, 250, 500, 1000, 2000, and 2500 repeated insertion/removal cycles. Wear and deformation of the attachment s were observed by scanning electron microscopy (SEM). Mann-Whitney U test (α=.05) and wilcoxon signed-rank test (α=.05) were performed to compare retentive force between each group and before and after 2500 repeated insertion/removal cycles. Results: In terms of initial retentive force and retentive force after 2500 repeated insertion/removal cycles, the AL group (15.24 ± 1.46 N and 9.74 ± 1.16 N) showed significantly smaller values than the LB group (43.53 ± 12.39 N and 22.99 ± 4.77 N) (P<.05). Also, in the loss of retentive force, the AL group (5.50 ± 1.08 N, 36.08%) showed a smaller value than the LB group (20.54 ± 11.89 N, 47.19%) (P<.05). Based on SEM analysis, The AL group showed noticeable wear and deformation in the patrix and the LB group in the matrix. Conclusion: Locator showed a higher initial retentive force than newly developed attachment, while the loss of retentive force was also higher. Both additional attachments are considered to have sufficient retentive force after repeated insertion/removal cycles.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.3
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• pp.336-340
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• 2010

Flash storages are prevalent as portable storage in computing systems. When we consider the detachability of Flash storage devices, data integrity becomes an important issue. To assure extreme data integrity, file systems synchronously write all file data to storage accompanying hot write references. In this study, we concentrate on the effect of hot write references on Flash storage, and we consider the effect of absorbing the hot write references via nonvolatile write cache on the performance of the FTL schemes in Flash storage. In 80 doing, we quantify the performance of typical FTL schemes for workloads that contain hot write references through a wide range of experiments on a real system environment. Through the results, we conclude that the impact of the underlying FTL schemes on the performance of Flash storage is dramatically reduced by absorbing the hot write references via nonvolatile write cache.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.2
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• pp.83-88
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• 2000

A Development of a data logger for monitoring wasted water is introduced. A characteristics of the system with microcontroller are simple and cheaper. A portable RAM card is consisted for saving a monitored data. Serial communication is adopted to communicate with a remote monitoring computer. CSMA/CD, which is used widely as MAC(Medium Access Control) in ethernet, is modified to apply a RS485 serial communication. When the measured values run over a limit values, the data logger takes alarm.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.1
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• pp.32-37
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• 1999

Twin blocks are bite-blocks that effectively modify the occlusal inclined plane to induce favorably directed occlusal forces by causing a functional mandibular displacement. One of the advantage is that full-time wear can be possible because of less interference with normal function such as eating and speaking. So rapid correction of malocclusion is expected. Reverse twin block appliance is modification for correction of class III malocclusion with sagittal component. For increased growth stimulation effort on premaxilla, lip pads can be added. But with lip pads, patients are incapable of full-time wear especially during mealtime. So, removable lip pads can be used for stimulation of growth on premaxilla without any restriction of function. The advantages of the reverse twin block appliance with removable lip pads are: 1. Full-time wear is possible (including mealtime). 2. Patients' cooperation and adaptation is excellent. 3. There is no period of dual bite. 4. Orthopedic correction is achieved by multiple modes, shortening the treatment time. The applied case shows that the reverse twin block appliance with removable lip pads is effective for treatment of class III malocclusion and can shorten the time of treatment.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.4
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• pp.354-361
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• 2011

There are still many limitations on fabricating dentures using digital method while computerized production of fixed prostheses utilizing intraoral scanner and CAD/CAM technology has propagated rapidly. Recently the digital solution of fabricating removable partial denture by applying haptic input device, electronic surveying, and rapid prototyping was introduced. In this case presentation, five patients were treated with surveyed crown and removable partial dentures by this digital solution. Fit of dentures was excellent except for one case which showed morphological difference between the actual teeth and that of master cast by the erroneous impression process. There also was not any problem of stability and retention after adaptation in the clinical setting.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.3
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• pp.207-214
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• 2015

Due to the limitations of conventional removable partial denture prostheses to treat a cleft lip & palate patient who shows scar tissue on upper lip, excessive absorption of the maxillary residual alveolar ridge, and class III malocclusion with narrow palate and undergrowth of the maxilla, 4 implants were placed on the maxillary edentulous region and a maxillary removable implant-supported partial denture was planned using a CAD/CAM milled titanium bar. Unlike metal or gold casting technique which has shrinkage after the molding, CAD/CAM milled titanium bar is highly-precise, economical and lightweight. In practice, however, it is very hard to obtain accurate friction-fit from the milled bar and reduction in retention can occur due to repetitive insertion and removal of the denture. Various auxiliary retention systems (e.g. $ERA^{(R)}$, $CEKA^{(R)}$, magnetics, $Locator^{(R)}$ attachment), in order to deal with these problems, can be used to obtain additional retention, cost-effectiveness and ease of replacement. Out of diverse auxiliary attachments, $Locator^{(R)}$ has characteristics that are dual retentive, minimal in vertical height and convenient of attachment replacement. Drill and tapping method is simple and the replacement of the metal female part of $Locator^{(R)}$ attachment is convenient. In this case, the $Locator^{(R)}$ attachment is connected to the milled titanium bar fabricated by CAD/CAM, using the drill and tapping technique. Afterward, screw holes were formed and 3 $Locator^{(R)}$ attachments were secured with 20 Ncm holding force for additional retention. Following this procedure, satisfactory results were obtained in terms of aesthetic facial form, masticatory function and denture retention, and I hereby report this case.