• Korean Chemical Engineering Research
• /
• v.48 no.4
• /
• pp.470-474
• /
• 2010

In this study, we presents a simple microfluidic approach for generating uniform Poly(ethylene glycol)(PEG) microfiber. Elongated flow pattern of monomer induced by sheath flow of immiscible oil as continuous phase is generated in Y-shape junction and in situ polymerization by UV exposure. For uniform microfiber, we investigate the optimized flow condition and draw phase diagram as function of Ca and Qd. At the region for stable elongated flow pattern, the microfiber generated in microfluidic chip is very uniform and highly reproducible. Importantly, the thickness of microfibers can be easily controlled by flow rate of continuous and disperse phase. We also demonstrate the feasibility for biological application as encapsulating FITC-BSA in PEG microfiber.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.5
• /
• pp.2325-2331
• /
• 2012

Planar square-spiral antenna using a strip conductor is proposed and analyzed for RFID system in UHF band operating from 860MHz to 960MHz. By varying the length of common line, detached distance, strip line-space, strip line-width and the number of spiral turn, the optimized antenna are designed and fabricated in compact size without a matching-stub between the input port of the proposed antenna and RFID tag chip. From the optimized results, the frequency bandwidth in VSWR<2 has covered 100MHz in the RFID UHF band. The antenna gain has obtained 3.5dBi at the center frequency of 910MHz and the desired beam pattern has shown directional pattern on elevation and azimuth angle. Therefore, the proposed antenna is suitable for practical RFID applications requiring various tag chips with the specific input impedance.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.93-93
• /
• 2016

Large scale integrated circuits (LSIs) has been improved by the shrinkage of the circuit dimensions. The smaller chip sizes and increase in circuit density require the miniaturization of the line-width and space between metal interconnections. Therefore, an extreme precise control of the critical dimension and pattern profile is necessary to fabricate next generation nano-electronics devices. The pattern profile control of plasma etching with an accuracy of sub-nanometer must be achieved. To realize the etching process which achieves the problem, understanding of the etching mechanism and precise control of the process based on the real-time monitoring of internal plasma parameters such as etching species density, surface temperature of substrate, etc. are very important. For instance, it is known that the etched profiles of organic low dielectric (low-k) films are sensitive to the substrate temperature and density ratio of H and N atoms in the H2/N2 plasma [1]. In this study, we introduced a feedback control of actual substrate temperature and radical density ratio monitored in real time. And then the dependence of etch rates and profiles of organic films have been evaluated based on the substrate temperatures. In this study, organic low-k films were etched by a dual frequency capacitively coupled plasma employing the mixture of H2/N2 gases. A 100-MHz power was supplied to an upper electrode for plasma generation. The Si substrate was electrostatically chucked to a lower electrode biased by supplying a 2-MHz power. To investigate the effects of H and N radical on the etching profile of organic low-k films, absolute H and N atom densities were measured by vacuum ultraviolet absorption spectroscopy [2]. Moreover, using the optical fiber-type low-coherence interferometer [3], substrate temperature has been measured in real time during etching process. From the measurement results, the temperature raised rapidly just after plasma ignition and was gradually saturated. The temporal change of substrate temperature is a crucial issue to control of surface reactions of reactive species. Therefore, by the intervals of on-off of the plasma discharge, the substrate temperature was maintained within ${\pm}1.5^{\circ}C$ from the set value. As a result, the temperatures were kept within $3^{\circ}C$ during the etching process. Then, we etched organic films with line-and-space pattern using this system. The cross-sections of the organic films etched for 50 s with the substrate temperatures at $20^{\circ}C$ and $100^{\circ}C$ were observed by SEM. From the results, they were different in the sidewall profile. It suggests that the reactions on the sidewalls changed according to the substrate temperature. The precise substrate temperature control method with real-time temperature monitoring and intermittent plasma generation was suggested to contribute on realization of fine pattern etching.

• The Journal of Korean Physical Therapy
• /
• v.6 no.1
• /
• pp.49-60
• /
• 1994

Stress is experienced when a person tries to maintain stability in the face of life change but is not able to meet the adaptive demands of change. This can be especially true for the parents who has a cerebral palsy childs who needs long term rare, where parents, are the primary source of care and responsibility. Successful coping leads to maintenance of the parents role and this has an effect on the health status of the child. This descriptive study was attempted to identify stress factors, levels and helpful coping patterns for parents who must take care of cerebral palsy children. Data were collected from 43 subjects who were parents of children diagnosed with cerebral palsy The informations gathered from March 25, 1994 to April 14, 1994 by means of structured questionnaires were analyzed. Two instruments were used to collect the data 1) Lee's stress questionnaire consisted of 33 stress factors and measured by four point Likert scale. 2) Modified Chronic Health Inventory for parents: The modified CHIP included 43 items of coping methods with four point Likert scale. The results of this study were as follows: 1) Stress items could have a maximum score of three points, for a total possible score of 132 points. The mean score for the total was 92.02 points. The item mean score was 2.85 points showing that the parents were experiencing moderate to much stress. 2) The items with the highest stress items were 16 items. The stress items with the lowest mean scores were 10 items. 3) Of the stress categories: The highest stress category was related to changes in the illness status of the child and difficulty in taking rare of the child. The second stressful category was related to the prognosis of the child's condition. The least stress was noticed to social-personal relationships and the responsibility of the care givers. 4) Items measuring coping in the parents had a maximum score of three points each with a total possible roping score of 172 points. The mean score for the total was 103,9 paints. The item mean score was 2.42 points indicating that there were responses of little helpful to moderately helpful on each coping pattern. 5) The most helpful coping items were 7 items. The least helpful coping items were 2 items. 6) Effectiveness of the coping for each patterns was examined : Understanding the illness condition from communication with parents of children with the same condition and consultation with the medical team was the most helpful coping pattern. Family's coorperation and integration and optimism were a moderately helpful coping pattern. Social support psychological stability and self esteem were the least helpful toping pattern. In conclusion, the highest stress for parents of children with cerebropalsy was found to be very stressful changes in the illness of the child and to taking care of a child who is suffering. The parents were helped by the coping methods using understanding of the illness condition through consultation with the medical learn and communication with parents in the same situation. Based on the knowledge, care could develop intervention strategies appropriate for them, help them to develop their effective coping patterns, and give support them in the process of coping with their stress.

• Proceedings of the KOSOMBE Conference
• /
• v.1991 no.05
• /
• pp.34-38
• /
• 1991

This paper describes and discusses the employment of EMG pattern analysis to provide upper-motor-neuron paraplegics with patient-responsive control of FES (functional electrical stimulation) for the purpose of walker-supported walking. The use of above - lesion EMG signals as a solution to the control problem is considered. The AR (autoregressive) parameters are identified by Kalman filter algorithm using DSP chip and classified by fuzzy theory. The control and stimuli part of the below-lesion are based on microprocessor(8031). The designed stimulator is a 4-channel version. The experiments described above have only attempted to discriminate between standing function and sit-down function. A further advantage of the this system is applied for motor rehabilitation of social readaption of paralyzed humans.

• Journal of Advanced Marine Engineering and Technology
• /
• v.33 no.8
• /
• pp.1239-1245
• /
• 2009

Currently, so many approaching methods are being developed to optimize the antenna size. In this paper, We fabricated Inverted-F type antenna attaching lumped components to solve the limitation of antenna size. Through experiments, a basic Inverted-F type antenna was fabricated and satisfied the adequate radiation pattern. After this, we researched the effect of antenna varied by matching circuit consist of chip type resistor, inductor, and capacitor. Using that elements, the antenna was matched at aim frequency. The proposed antenna's size is $7\;{\times}\;24\;mm$ that is very small size against the resonance frequence. Measuring the developed antenna, Its return loss was -18dB. Thus, this antenna can be used for Z-wave systems.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.45 no.11
• /
• pp.95-101
• /
• 2008

We have used diversely the multilayer ceramic oscillator of the SMD(Surface Mounted Device) package technology that connects the crystal with the chip package. Such an oscillator occurs a stray inductance and a parasitic capacitance by the length and inner pattern. And it has been happened an amplitude attenuation and signal loss due to the reflection of power source and noise component. So we don't evaluate the precise performance of the oscillator for these factors. In this paper we have developed the Jig system to evaluate the performance of the oscillator. Through this system, we will expect an advanced performance of the oscillator and redesign an oscillator of the low jitter characteristics and low phase noise.

• Journal of the Korea Society of Computer and Information
• /
• v.9 no.1
• /
• pp.9-15
• /
• 2004

New WSW(Wrap Side Wall) is proposed to decrease junction electric field in this paper. WSW process is fabricated after first gate etch, followed NM1 ion implantation and deposition & etch nitride layer. New WSW structure has buffer layer to decrease electric field. Also we compared the hot carrier characteristics of WSW and conventional. Also, we design a test pattern including pulse generator, level shifter and frequency divider, so that we can evaluate AC hot carrier degradation on-chip. It came to light that the universality of the hot carrier degradation between DC and AC stress condition exists, which indicates that the device degradation comes from the same physical mechanism for both AC and DC stress. From this universality, AC lifetime under circuit operation condition can be estimated from DC hot carrier degradation characteristics.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2011.10a
• /
• pp.9-9
• /
• 2011

The transfer of nano-science accomplishments into technology is severely hindered by a lack of understanding of barriers to nanoscale manufacturing. The NSF Center for High-rate Nanomanufacturing (CHN) is developing tools and processes to conduct fast massive directed assembly of nanoscale elements by controlling the forces required to assemble, detach, and transfer nanoelements at high rates and over large areas. The center has developed templates with nanofeatures to direct the assembly of carbon nanotubes and nanoparticles (down to 10 nm) into nanoscale trenches in a short time (in seconds) and over a large area (measured in inches). The center has demonstrated that nanotemplates can be used to pattern conducting polymers and that the patterned polymer can be transferred onto a second polymer substrate. Recently, a fast and highly scalable process for fabricating interconnects from CMOS and other types of interconnects has been developed using metallic nanoparticles. The particles are precisely assembled into the vias from the suspension and then fused in a room temperature process creating nanoscale interconnect. The center has many applications where the technology has been demonstrated. For example, the nonvolatile memory switches using (SWNTs) or molecules assembled on a wafer level. A new biosensor chip (0.02 $mm^2$) capable of detecting multiple biomarkers simultaneously and can be in vitro and in vivo with a detection limit that's 200 times lower than current technology. The center has developed the fundamental science and engineering platform necessary to manufacture a wide array of applications ranging from electronics, energy, and materials to biotechnology.

• KSBB Journal
• /
• v.24 no.6
• /
• pp.515-520
• /
• 2009

This study presented facile method of cell patterning using fabricated PDMS patterns on polyelectrolyte coated surface. This basic principle is the fabrication of functional surface presenting two orthogonal surfaces such as cell adhesive and repellent properties. Cell adhesive surface was firstly fabricated with simple coating of polyelectrolyte multilayer. And then, the desired patterns of PDMS for the prevention of nonspecific binding of cells were transferred onto the previously formed thin film of polyelectrolyte multilayer. Thus, we could prepare novel functional surface simultaneously containing PDMS and polyelectrolyte region. As expected, the PDMS regions showed effective prevention of nonspecific binding of cell and the other region, exposed polyelectrolyte area, provided cell adhesive environment. The height of formed PDMS structure was about 100 nm. Based on this method, cell patterning can be successfully obtained with various pattern shapes and sizes. Therefore, we expect that this simple method will be useful platform technology for the development of cell chip, cell based assay system, and biochip.