• Korean Journal of Materials Research
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• v.13 no.4
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• pp.266-270
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• 2003

We studied BCl$_3$ dry etching of GaAs in a planar inductively coupled plasma system. The investigated process parameters were planar ICP source power, chamber pressure, RIE chuck power and gas flow rate. The ICP source power was varied from 0 to 500 W. Chamber pressure, RIE chuck power and gas flow rate were controlled from 5 to 15 mTorr, 0 to 150 W and 10 to 40 sccm, respectively. We found that a process condition at 20 sccm $BCl_3$ 300 W ICP, 100 W RIE and 7.5 mTorr chamber pressure gave an excellent etch result. The etched GaAs feature depicted extremely smooth surface (RMS roughness < 1 nm), vertical sidewall, relatively fast etch rate (> $3000\AA$/min) and good selectivity to a photoresist (> 3 : 1). XPS study indicated a very clean surface of the material after dry etching of GaAs. We also noticed that our planar ICP source was successfully ignited both with and without RIE chuck power, which was generally not the case with a typical cylindrical ICP source, where assistance of RIE chuck power was required for turning on a plasma and maintaining it. It demonstrated that the planar ICP source could be a very versatile tool for advanced dry etching of damage-sensitive compound semiconductors.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2003.10a
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• pp.1-1
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• 2003

It is clear that computers will play a key role in the biology of the future. Even now, it is virtually impossible to keep track of the key proteins, their names and associated gene names, physical constants(e.g. binding constants, reaction constants, etc.), and hewn physical and genetic interactions without computational assistance. In this sense, computers act as an auxiliary brain, allowing one to keep track of thousands of complex molecules and their interactions. With the advent of gene expression array technology, many experiments are simply impossible without this computer assistance. In the future, as we seek to integrate the reductionist description of life provided by genomic sequencing into complex and sophisticated models of living systems, computers will play an increasingly important role in both analyzing data and generating experimentally testable hypotheses. The future of bioinformatics is thus being driven by potent technological and scientific forces. On the technological side, new experimental technologies such as microarrays, protein arrays, high-throughput expression and three-dimensional structure determination prove rapidly increasing amounts of detailed experimental information on a genomic scale. On the computational side, faster computers, ubiquitous computing systems, high-speed networks provide a powerful but rapidly changing environment of potentially immense power. The challenges we face are enormous: How do we create stable data resources when both the science and computational technology change rapidly? How do integrate and synthesize information from many disparate subdisciplines, each with their own vocabulary and viewpoint? How do we 'liberate' the scientific literature so that it can be incorporated into electronic resources? How do we take advantage of advances in computing and networking to build the international infrastructure needed to support a complete understanding of biological systems. The seeds to the solutions of these problems exist, at least partially, today. These solutions emphasize ubiquitous high-speed computation, database interoperation, federation, and integration, and the development of research networks that capture scientific knowledge rather than just the ABCs of genomic sequence. 1 will discuss a number of these solutions, with examples from existing resources, as well as area where solutions do not currently exist with a view to defining what bioinformatics and biology will look like in the future.

• Journal of Technology Innovation
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• v.21 no.2
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• pp.137-167
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• 2013

This article estimates the scale of impact of expanding governmental fiscal expenditure for R&D investment on the private business enterprise's investment for R&D, and the relationship between business enterprise and university for expanding investment of R&D. According to my results, first, an expanding fiscal expenditure from government for R&D investment leads to increase R&D investment from business enterprise. However, an expanding expenditure from university rather leads to decrease R&D investment from business enterprise. Secondly, the crowding-out effect of expanding R&D investment from University on business enterprise's is very strong, and it is affected by structural changes such as the country's economic power, fiscal stance and cyclical volatility. Third, the more governmental expenditure on university expansive is, the stronger asymmetric relationship between business enterprise and university is, and investment sources of university from business enterprise is the main factor of this relationship. Finally, it is not easy to solve out this asymmetric relationship even through the governmental subsidy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2215-2224
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• 2013

This study performed empirical analysis to estimate SMEs needs in terms of business support policy by growth stages(start-up growth expansion). The subject is the SMEs in Cheonan and Asan, ChungNam and the results are as follows. First, In the initial start-up stage, management plays a key role in dealing with money, labor force, markets and technology while running the organization is a key role of the management in the expansion stage. Major policies to help SMEs grow includes money provision needed in the start-up stage, domestic marketing assistance and the provision of human resources in the growth stage, and assistance in foreign marketing and R&D in the expansion stage. Second, To achieve markets businesses aim at entering the existing and niche markets in the initial phase, and creating new markets in the growth phase. Third, Labor force for technology, sales and management planning in the start-up stage, marketing in the growth stage, and labor force for production in the expansion stage are core man- power needed. Fourth, Money for technology development, securing land for factories, organizing man power, securing markets and running the company is needed in the initial and growth stages while fund for facility investment is needed to grow in the expansion stage. Five, Regarding technology, the initial stage needs technology related to new product development, renewing existing products, improving the existing manufacturing process or developing new manufacturing process, while the growth stage needs processing techniques, and the expansion stage needs technology for developing new manufacturing process. Sixth, Making supply contracts with conglomerates, SMEs and public institutions, and sales to foreign markets are ways for SMEs to grow sales. Seventh, What SMEs wish to get includes business incubating support, R&D assistance, information exchanges, practical use of the R&D results, merchandising support, help with the land to build factories and custom-made support for management in the foundation stage while the support they want to get in the growth stage and in the expansion stage is training assistance and trial production respectively.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.572-575
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• 2005

A novel pneumatic artificial muscle actuator (PAM actuator), which has achieved increased popularity to provide the advantages such as high strength and high power/weight ratio, low cost, compactness, ease of maintenance, cleanliness, readily available and cheap power source, inherent safety and mobility assistance to humans performing tasks, has been regarded during the recent decades as an interesting alternative to hydraulic and electric actuators. In order to realize satisfactory control performance, a variable damper Magneto Rheological Brake (MRB), Is equipped to the Joint of the manipulator. Superb mixture of conventional PID controller and a phase plane switching control method brings us a novel controller. This proposed controller is appropriate for a kind of plants with nonlinearity, uncertainties and disturbances. The experiments were carried out in practical PAM manipulator and the effectiveness of the proposed control algorithm was demonstrated through experiments, which had proved that the stability of the manipulator can be improved greatly in a high gain control by using MRB with phase plane switching control method and without regard for the changes of external inertia loads.

• Journal of Power System Engineering
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• v.16 no.1
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• pp.12-18
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• 2012

The fluid performance is one of the key design factors considered during the development of torque converters especially at conceptual design stages. Therefore the design environment that allows an easy access to legacy data of fluid performance could be critical to reduce the design life cycle as well as to increase the performance of the torque converter. In this paper we present a computer-based system that enables designers to utilize massive legacy data for their design of torque converters. For the implementation of the system we propose a standard format for the legacy data and build them into the database to be efficiently shared by designers in the company. Also we provide numerous analysis tools in the system that allow, for example, database management, data viewing and document generation for search, analysis and reporting. In the paper the implementation of the system is introduced in detail with its effective user interface.

• 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.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.3
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• pp.1301-1318
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• 2017

In order to utilize the licensed channel of cognitive radio (CR) when the primary user (PU) is detected busy, a benefit-exchange access mode based on cooperative communication is proposed to allow secondary user (SU) to access the busy channel through giving assistance to PU's communication in exchange for some transmission bandwidth. A holistic joint optimization problem is formulated to maximize the total throughput of CR system through jointly optimizing the parameters of cooperative spectrum sensing (CSS), including the local sensing time, the pre-configured sensing decision threshold, the forward power of cooperative communication, and the bandwidth and transmission power allocated to SUs in benefit-exchange access mode and traditional access mode, respectively. To solve this complex problem, a combination of bi-level optimization, interior-point optimization and exhaustive optimization is proposed. Simulation results show that, compared with the tradition throughput maximizing model (TTMM), the proposed holistic joint optimization model (HJOM) can make use of the channel effectively even if PU is busy, and the total throughput of CR obtains a considerable improvement by HJOM.

• Transactions on Electrical and Electronic Materials
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• v.12 no.3
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• pp.106-109
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• 2011

We investigated the etching characteristics of titanium nitride (TiN) thin film in $BCl_3$/Ar inductively coupled plasma. The etching parameters were the gas mixing ratio, radio frequency (RF) power, direct current (DC)-bias voltages and process pressures. The standard conditions were as follows: total flow rate = 20 sccm, RF power = 500 W, DC-bias voltage = -100 V, substrate temperature = $40^{\circ}C$, and process pressure = 15 mTorr. The maximum etch rate of TiN thin film and the selectivity of TiN to $Al_2O_3$ thin film were 54 nm/min and 0.79. The results of X-ray photoelectron spectroscopy showed no accumulation of etch byproducts from the etched surface of TiN thin film. The TiN film etch was dominated by the chemical etching with assistance by Ar sputtering in reactive ion etching mechanism, based on the experimental results.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.539-542
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• 2006

Many researches about next generation vehicles are trending toward HEV which has better fuel economy than an internal-combustion engine. But existing HEV has some defects at specific running states(eg. highway running It is possible that dual-mode hybrid system overcomes that defects. Mode change parameter, ${\gamma}$ helps to analyse the mode changing of dual mode hybrid and is applied at a numerical analysis on testing the performance. There is an additional constraint when vehicles drive on engine mode. No power assistance of battery applies on engine mode. Because vehicles must be sustained by only engine power while vehicle drives on constant speed mode. At the conclusion of this paper, graphs show the ability of motors that satisfy the equilibrium of the lever system. Designers can roughly determine capacities of the motors, parameters of the lever system by this analysing method.