• Journal of Institute of Control, Robotics and Systems
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• v.8 no.9
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• pp.788-794
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• 2002

To improve surgical result of total hip arthroplasty (THA), there has been some approaches using a robotic milling system, which can make a precise cavity in the femur. Usually, to carve a femur, the surgical robot is controlled by a pre-programmed tool-path regardless of a surgeon's experience and Judgment. This paper presents a control method of a surgical robot for THA, which can be used as an advanced surgical tool. With a master/slave combined surgical robot, surgeon can directly control the motion and velocity of a surgical robot. The master/slave-combined robot is controlled to display a specific admittance for a surgeon's force to the surgical robot velocity. To prevent the over-carving of a femur, virtual hard wall is displayed on the surgical boundary. To evaluate the proposed control method of the master/slave-combined surgical robot, 2-DOF master/slave-combined manipulator is used in experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1601-1604
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• 2005

The demand increasing of optical applications like as display devices derives interest for fabrication process. The product s development is apt to fabricate numerous thin and wide surfaces with micro pattern. Naturally that needs injection molding fabrication for the mass production. In existing manufacturing, the product quality is controlled by input fabrication condition from the outside. That can be called as a try and error method and not fundamentally solve the troubles; imperfect replication, war page, short shot, etc. To understand the cause and bring a solution, it is needed that check of changing in the cavity. This study can catch them. Data acquisition system about temperature and pressure distribution is settled and can get some data. From this research, other studies related with DAQ in cavity can start on the easier step.

• Journal of the Korean Society of Safety
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• v.29 no.6
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• pp.40-45
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• 2014

In display such as LCD, LED, and AMOLED or semiconductor related industries are required to have static ionizer in order to produce reliable goods. The most general type of ionization is called, "corona discharge" that has a slight chances to generate unequal and unstable amount of each +/- ion to the target object. Then, the ionization performance will drastically decrease and end up with quality deterioration problem. continually "A study on the improvement of the performance of pulsed AC ion bar(1)", we have studied consecutive study to improve the current issue via appling "partition wall" at air nozzle surrounding. The results were that the charge decay time and the ion balance was maintained the satisfied range that was within 5 second and ${\pm}50$ V for a 180 days period of time. In additions, the contamination status on the electrode surface was investigated for a 180 days. The little particles was deposited on the electrode surface.

• The Journal of Korea Robotics Society
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• v.15 no.4
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• pp.323-329
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• 2020

This paper presents a control algorithm for a wearable walking aid robot for subjects with paraplegia after stroke. After a stroke, a slow, asymmetrical and unstable gait pattern is observed in a number of patients. In many cases, one leg can move in a relatively normal pattern, while the other leg is dysfunctional due to paralysis. We have adopted the so-called assist-as-needed control that encourages the patient to walk as much as possible while the robot assists as necessary to create the gait motion of the paralyzed leg. A virtual wall was implemented for the assist-as-needed control. A position based admittance controller was applied in the swing phase to follow human intentions for both the normal and paralyzed legs. A position controller was applied in the stance phase for both legs. A power controller was applied to obtain stable performance in that the output power of the system was delimited during the sample interval. In order to verify the proposed control algorithm, we performed a simulation with 1-DOF leg models. The preliminary results have shown that the control algorithm can follow human intentions during the swing phase by providing as much assistance as needed. In addition, the virtual wall effectively guided the paralyzed leg with stable force display.

• Journal of Chest Surgery
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• v.24 no.8
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• pp.792-796
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• 1991

Immature teratoma can be viewed as intermediate between mature teratoma and embryonal carcinoma. Unlike the mature teratoma, elements of the three perm cell layers are incompletely differentiated and not arranged in organoid fashion In some area, more mature forms of these tissues may also be seen, Although this tumor is clearly malignant, they may not display clear-cut cytologic features of malignancy. The clinical prognosis is poor. We have experienced one case of recurrent immature teratoma. In first operation[1987, April], tumor of anterior mediastinum was removed with wedge resection of ant. segment of RUL % med. segment of RML. In 2nd operation[1990, June], recurrent teratoma of right inner thoracic wall was resected with partial 5th rib resection and wedge resection of lat. segment of middle lobe. Two months later, the 3rd operation[1990, September] was done, which was a removal of mass on thoracic wall near sup, segment of RLL and partial rib resection of 3rd, 4th & 5th. In November 1990, last operation[4th operation] was made. It was enucleation of walnut sized tumor located between medial segment of RML, and 4th. intercostal space, well encapsulated with endothoracic fascia and invaded into lung parenchyme, Adjuvant chemotherapy was done after each operation, but radiotherapy[5000 Rad] was done only after 1st operation. There was no evidence of recurrence after last operation. The patient is well-being still now.

• Korean Institute of Interior Design Journal
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• v.17 no.5
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• pp.99-106
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• 2008

Based on extraction items derived from previous related studies on viewing experiences in art museums, this study is conducted to investigate extraction factors that affect viewing satisfactions and to suggest a guideline for an effective viewing environment by clarifying a hierarchy among the extraction factors. For this study, a survey was given to museum visitors, and statistical analyses were conducted on data obtained from the survey. The results of this study are summarized as follows; 1. From an analysis of extraction items that affect overall viewing satisfaction, space and art works were found to be relatively satisfactory. 2. From correlation analyses of extraction items, a degree of concentration on art works was found to most 'affect the viewing satisfactions of art museums. 3. From factor analyses, extraction items were reduced to 11 extraction factors, and a simple extraction structure affecting the viewing satisfactions in art museums. 4. From multiple regression analyses, a extraction factors were derived, and a relative hierarchy among the factors was found.

• Transactions of Materials Processing
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• v.17 no.8
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• pp.657-661
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• 2008

Recently, products of electronic industry and related parts are required to have the thickness thinner and thinner to reduce the part weight. To go with this trend, LGP(light guide plate) of LCD-BLU(Liquid Crystal Display-Back Light Unit: It is one of kernel parts of LCD) for cell phone has the thickness of ${\sim}0.3mm$ and the battery case of cell phone has ${\sim}0.25mm$. Accordingly, high speed injection molding is required to mold products which have thinner parts. To achieve high speed injection and proper control of hydraulic unit, various design was applied to conventional injection unit. In the present paper, we concentrated on the molding stability of hydro-mechanical high speed injection machine to make an LGP of 0.3mm thickness.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.115-116
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• 2000

Influence of sustain pulse-width on electro-luminous efficiency is experimentally investigated for surface discharge of AC-PDP. It is found that the firing voltage is decreased as the pulse-width is increased from $2\;{\mu}s$ to $8\;{\mu}s$ with sweeping frequency range of 10 kHz to 50 kHz. It has been found that the optimal sustain pulse-width is in the range of $3{\sim}4\;{\mu}s$ under driving frequency range of 30 kHz and 50 kHz, based on observations of memory coefficient, wall charge, and wall voltage as well as luminous efficiency.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2233-2235
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• 1999

The ac plasma display panel(PDP) is a flat light-emitting gas discharge device. Discharge gases directly take effects to the discharge phenomena of ac PDP. Therefore it is necessary to understand the characteristics of the discharge gases. In this paper, we have studied the effects of discharge gases by voltage transfer curves which show the discharge characteristics of ac PDP and the change of the effective wall capacitance during a discharge which depends on lateral spreading of charge distribution and the strength of discharge. As gas pressure increases, memory margins increases. and the firing voltage of a mixed gas is lower than that of a single gas such as He gas. The minimum sustain voltage and the maximum sustain voltage or firing voltage increases with decrease in the frequency. The effective wall capacitance increases as the discharge strength that is, the gap voltage between discharge electrodes increases.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.1
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• pp.8-17
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• 2023

In conventional liquid crystal display(LCD) manufacturing process, Indium Tin Oxide(ITO) as transparent electrode and rubbing process of polyimide as alignment layer are essential process to apply electric field and align liquid crystal molecules. However, there are some limits that deposition of ITO requires high vacuum state, and rubbing process might damage the device with tribolectric discharge. In this paper, we made nanocomposite with PEDOT:PSS and MWNT to replace ITO and constructed alignment layer by nano imprint lithography with nano wrinkle pattern, to replace rubbing process. These replacement made that only one PEDOT:PSS/MWNT film can function as two layers of ITO and polyimide alignment layer, which means simplification of process. Transferred nano wrinkle patterns functioned well as alignment layer, and we found out lowered threshold voltage and shortened response time as MWNT content increase, which is related to increment of electric conductivity of the film. Through this study, it may able to contribute to process simplification, reducing process cost, and suggesting a solution to disadvantage of rubbing process.