• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.105-105
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• 2009

$ZrO_2$ is one of the most attractive high dielectric constant (high-k) materials. As integrated circuit device dimensions continue to be scaled down, high-k materials have been studied more to resolve the problems for replacing the EY31conventional $SiO_2$. $ZrO_2$ has many favorable properties as a high dielectric constant (k= 20~25), wide band gap (5~7 eV) as well as a close thermal expansion coefficient with Si that results in good thermal stability of the $ZrO_2/Si$ structure. In order to get fine-line patterns, plasma etching has been studied more in the fabrication of ultra large-scale integrated circuits. The relation between the etch characteristics of high-k dielectric materials and plasma properties is required to be studied more to match standard processing procedure with low damaged removal process. Due to the easy control of ion energy and flux, low ownership and simple structure of the inductively coupled plasma (ICP), we chose it for high-density plasma in our study. And the $BCl_3$ included in the gas due to the effective extraction of oxygen in the form of $BCl_xO_y$ compound In this study, the surface kinetic properties of $ZrO_2$ thin film was investigated in function of Ch addition to $BCl_3/Ar$ gas mixture ratio, RF power and DC-bias power based on substrate temperature. The figure 1 showed the etch rate of $ZrO_2$ thin film as function of gas mixing ratio of $Cl_2/BCl_3/Ar$ dependent on temperature. The chemical state of film was investigated using x-ray photoelectron spectroscopy (XPS). The characteristics of the plasma were estimated using optical emission spectroscopy (OES). Auger electron spectroscopy (AES) was used for elemental analysis of etched surface.

• Archives of design research
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• v.18 no.4 s.62
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• pp.119-128
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• 2005

This paper presents an intuitive 3D modeling interlace based on a field study and prototype development. The process and tools of modeling were observed in workshops of professional design model making, day modeling, wood caning and glass crafting. The Spray Modeling interlace was developed from the observational analysis of the field study. It is a 3D modeling interface which combines particle spraying and day modeling in Virtual or Augmented Reality space. Virtual volume particles are sprayed on frames in Augmented Reality space as day modeling. It adopts a real air spay gun as a tangible interface device which provides coherent sound and air-force feedback. The prototype development and a user study showed that the interface supports new patterns of form development and expression. Control interfaces and requirements of auxiliary devices were found to be improved. This study examines the potential of the new interlace for designers working in 3D virtual and augmented reality. The new spraying interface is also expected to be used as an alternative interface in 3D computer workspace, games, education software and media art.

• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.5
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• pp.391-399
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• 2005

Laser-generated ultrasonic inspection system is a non-contact scanning inspection device with high spatial resolution and wide bandwidth. The amplitude of laser-generated ultrasound is varied according to the energy of pulse laser and the surface conditions of an object where the CW measuring laser beam is pointing. In this paper, we correct the generating errors by measuring the energy of pulse laser beam and correct the measuring errors by extracting the gain information of laser interferometer at each time. h dynamic stabilizer is developed to stably scan on the surface of an object for an laser-generated ultrasonic inspection system. The developed system generates ultrasound after adaptively finding the maximum gain time of an laser interferometer and processes the signal in real time after digitization with high speed. In this paper, we describe hardware configuration and control algorithm to build a stable laser-generated ultrasonic inspection system. Also, we confirmed through experiments that the proposed correction method for the generating errors and measuring errors is effective to improve the performance of a system.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.2
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• pp.89-93
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• 2017

GaN single crystals were grown by controlling of various processing parameters such as growing temperature, V/III ratio and growing rate. We optimized thickness of bulk GaN single crystal by analyzing defect of surface and inside of the GaN single crystal for application to high brightness and power device. 2-inch bulk GaN single crystals were grown by HVPE (hydride vapor phase epitaxy) on sapphire and their thickness was 0.3~7.0 mm. Crystal structure of the grown bulk GaN was analyzed by XRD (X-ray diffraction). The surface characteristics of the grown bulk GaN were observed by OM (optical microscope) and SEM (scanning electron microscopy) with measuring EPD (etch pits density) of the GaN crystals.

• Progress in Medical Physics
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• v.8 no.1
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• pp.25-29
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• 1997

Ir-192 source activity for high dose rate brachytherapy is measured using Farmertype ionization chamber. The source-to-chamber distance is 10 cm and the measured charge unit is converted to activity unit. The measured values are compared to the values provided from vendor. Because of time dependency of Ir-192 source activity, the activities are regularly checked and compared to calculated values. As the accuracy of Ir-192 source activity is depend on the mechanical measurement setup, we estimated the precision of remote controlled source dwell position using home-made device and film scanner. The difference between measured and predicted dwell position is within 1 mm. As a result, the errors of source activity are 0.7${\pm}$1.5 ％ for measured and vendor-provided values and 0.l${\pm}$1.2％ for measured and time-dependent calculated vlaues. In conclusion, our measured activity has been comparable to the values provided from vendor and our brachytherapy unit has been very accurate until now. Regular quality control of brachytherapy is essential for successful treatment which depends on the accuracy of source position and activity.

• Archives of design research
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• v.17 no.2
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• pp.5-14
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• 2004

Introducing human capacities of control and sensation which have been overlooked into Human-Computer Interaction(HCI), Ubiquitous computing, Augmented Reality and others have been researched recently. New vision of HCI has embodied in Tangible User Interface(TUI). TUI allows users to grasp and manipulate bits with everyday physical object and architectural surface and also TUI enables user to be aware of background object at the periphery of human perception using ambient display media such of light, sound, airflow and water movement. Tangibles, physical object which constitutes TUI system, is the physical object embodied digital bit. Tangibles is not only input device but also the configuration of computing. To get feedback of computing result, user controls the system with Tangibles as action and the system represents reaction in response to User's action. User appreciates digital representation (sound, graphic information) and physical representation (form, size, location, direction etc.) for reaction. TUI's characters require the consideration about both user's action and system's reaction. Therefore we have to need the method to be concerned about physical object and interaction which can be combined with action, reaction and feedback.

• Science of Emotion and Sensibility
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• v.13 no.3
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• pp.441-448
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• 2010

In the aging society, the walking assist robot is a necessary device for being able to help the older and the lower limb disabled people to walk. In order to produce a convenient robot for the older and the lower limb disabled, it is needed for the research to detect the implicit walking intention and to control robot by a user's intention. This study is a previous study to develop the detection model of the walking intention and analyze the user's walking intention while a person is walking with Lofstrand crutches, by the combination of FSR and tilt signals. The FSR sensors attached user's the palm and the soles of foot are sensing force/pressure signals from these areas and are used for detecting the walking intention and states. The tilt sensor acquires roll and pitch signal from area of vertebrae lumbales and reflects the pose of the upper limb. We can recognize the user's walking intention such as 'start walking', 'start of right or left foot forward', and 'stop walking' by the combination of FSR and tilt signals can recognize.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.121-125
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• 2002

Purpose : The purpose of this study was to assess the clinical outcomes and radiological changes of arthroscopic augmentation with synthetic polyester ligament for posterior cruciate ligament injury Materials and Methods : The assessment was made among 60 patients who underwent arthroscopic augmentation with synthetic polyester ligament (ABC ligament, Surgicraft, U.K.) into the substance of ruptured PCL proper under the arthroscopic control from January, 1990 to January, 1996 and whose follow-up period was more than 5 years (average 7.8 years). The results were analyzed by using the posterior stress radiographs by Telos stress device, KT-2000 arthrometer and the clinical assessment by using Lysholm knee score. Results : The average difference of posterior displacement on stress radiographs were 13.2 mm preperatively and 3.6 mm at last follow up. Both knee showed minimal difference on KT-2000 arthrometer (0.7 mm on 20 lb) at the last follow-up. The mean Lysholm knee score was 49.2 preoperatively and improved to 84.3 post-operatively. Conclusion : Authors observed that long-term results of arthroscopic augmentation with synthetic polyester ligament for PCL injury were similar with those using human allograft. Taking these results into consideration, the synthetic polyester ligament is assumed to be a method of treatment of the PCL injury.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.5
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• pp.1235-1243
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• 2012

This study was attempted in order to offer basic data for performing systematic and desirable task through improving job by surveying the actual condition and the task weight in dental hygienists. As a result of analyzing daily task weight in subjects of this study, the ratio of medical-cure cooperation task was indicated to be highest with 35.45%. It was indicated to be in order of periodontal therapy service with 21.54%, of administration & management task with 16.08%, of oral health education task with 15.88%, and of preventive treatment service with 11.23%. As for kind-based utilization ratio of the oral health education contents and oral health education data, a toothbrushing education method by subject was indicated most highly with 3.70 points. It was indicated to be in order of usage on oral hygiene device with 3.51 points, of educational method on regular check-up with 3.26 points, of educational method of preventing dental disease with 3.13 points, and of educational method on diet control with 1.39 points. Jaw-plate model was indicated to be used the most with 38.0%. It was indicated to be in order of orally explaining with 23.9% and of camera inside the mouth with 12.2%. Thus, establishment of a system is considered to be necessary in order to promote quality of oral health education for patients in the future by performing diverse programs with high utilization value in addition to a steady interest.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.8
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• pp.1620-1625
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• 2004

To advance fisheries, we set developmental directions of fishery information by grasping present situations and analyzing maritime & fisheries issues. We promote various policies through effective systematical information data bases, based on both control and utilization of oceanic resources. For these puposes, it is imperative that we set up fisheries communication networks. There are satellite assisted informational networks to assist fishing vessels with their marine based movements. However, there's no hope for poorly equipped fishermen to adopt this network because of extravagant network call charges. So we think that using existing SSB communication system is the best plan. We organize fishery communication network by HF SSB communication which doesn't have operational costs. We build wireless transmitting and receiving stations that are basic systems of informnation, and equip wireless data communication systems by the use of wireless communication network protocols in coastal stations. It is necessary that a fish boat has a terminal device for wireless data communication. In this research we can conclude that if we transmit the location of a fishing boat in-real time through GPS channels then we propose that some methods be formulated to able terminal devices on fishing boats to collect various types of information, such as meteorological and oceanic conditions.