• Transactions of the Korean Society of Automotive Engineers
• /
• v.15 no.4
• /
• pp.27-32
• /
• 2007

Head-Up Display system makes it possible for the driver to be informed of important vehicle data such as vehicle speed, engine RPM or navigation data without taking the driver's eyes off the road. Long focal length optics, LCD with bright illumination, image generator and vehicle interface controllers are key parts of head-up display system. All these parts have been designed, developed and applied to the test vehicle. Virtual images are located about 2m ahead of the driver's eye by projecting it onto the windshield just below the driver's line of sight. Developed head-up display system shows satisfactory results for future commercialization.

• Proceedings of the Korea Society for Industrial Systems Conference
• /
• 2002.06a
• /
• pp.62-68
• /
• 2002

In this paper, we have developed the Up-Convertor for CATV Head/End using 54∼750 MHz. We have individually designed and fabricated the main circuit of Up-converter such as Amplifier, frequency mixer, Voltage Controlled Oscillator(OSC), and we have realized the implementation for System Module in each circuit, so we have achieved a small size, light weight. and we have focused to have a shielding technique in high frequency bandwidth.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07b
• /
• pp.992-993
• /
• 2002

We have fabricated the diffractive optical head(DOH) for optical pick up, which one adaptable to a optical recoding information storage. DOH consists of a focusing grating coupler(FGC) and a solid immersion Jens(SIL). FGC is device that the light converge into a focus by surface lattice. FGC have been studied as a potential application of pick up head for the information storage. In this study, FGC was designed and fabricated to make focus near to possible diffraction limit. We also fabricated recording head combined with SIL. The focus was measured in the range of $1.1{\mu}m$ as near to possible diffraction limit in the FGC having a focusing length of $600{\mu}m$ and a lattice area of 500 * $500{\mu}m$.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.1 no.1
• /
• pp.37-49
• /
• 1994

The purpose of this study was to measure the oral temperature, skin temperature, and subjective discomfort according to the application time of ice bag on thigh, head, and abdomen. This study was also intended to suggest nursing principles about ice bag application by exploring the recovery time of skin temperature after the removal of ice bag. The design of this study was $8{\times}3$ factorial design with one sample repeated measure. Here, the application time of ice bag(criteria, 5min, 10min, 20min, 30min, 40min, 50min, 60min) and the application site of ice bag(thigh, head, abdomen) were independent variables. The subjects were 10 university woman students, and data collection was made from July, 1 to August 30, 1992. Rubber ice bag halfly filled with ice was covered with towel and applied on thigh, head and abdomen in other three days. Before applying the ice bag, oral temperature and skin temperature were checked for criteria. After ice bag was applied, skin temperature, oral temperature and VAS score were checked at first 5 minutes elapsed, and every 10 minutes until 60 minutes. After that, ice bag was removed, and oral temperature and skin temperature were also measured every ten minutes until 60 minutes. In this study, skin temperature and core temperature were measured by thermistor probe, and subjective discomfort was measured by 200mm VAS (Visual Analogue Scale). Some of the findings were as follows : 1. There were significant differences in skin temperature among the three application sites of ice bag as time go by. It was most decreased to $15.87^{\circ}C$ in thigh, and $19.47^{\circ}C$ in abdomen at 50 minutes after the application of ice bag, whereas $26.1^{\circ}C$ at 40 minutes in head. Before the application of ice bag, skin temperature showed significant differences in three sites, so that they were compared after the criteria was covariated. In other words, there was significantly more decrease of skin temperature in thigh and abdomen than head, after ice bag was applied for 20 minutes and more. 2. There was no significant difference in core temperature among the three application sites of ice bag during the time of application 3. There was no significant difference in subjective discomfort (VAS) among the three application sites of ice bag. 4. After the removal of ice bag, the recovery of skin temperature was significantly different in three sites during first 30 minutes. In head, skin temperature came up to criteria at 30 minutes after the removal of ice bag, but it was not recovered In thigh and abdomen even 60 minutes elapsed. 5. After the removal of ice bag, there was no significant difference in oral temperature among the three application sites of ice bag. 6. There was significant correlation between the skin temperature and VAS score only in thigh. In conclusion, it is suggested that head in more suitable site for the application of ice bag if it is used for the relief of fever or pain. When we apply ice bag on thigh or abdomen for the relief of pain, careful attention is required.

• The Korean Journal of Emergency Medical Services
• /
• v.23 no.2
• /
• pp.99-107
• /
• 2019

Purpose: This study aimed to identify the position for the most accurate head-up cardiopulmonary resuscitation (CPR) by comparing saddle position CPR (SPCPR) and traditional CPR (TCPR). Methods: Sixty certified persons who completed a basic life support provider course between May 1 and June 21, 2019 were enrolled in the study. The participants were asked to perform 2 minutes of CPR, and the depth of chest compression, rate, position, full release, and hands off time were assessed. Accuracy was evaluated based on data collected from a smart phone application connected to the manikin via bluetooth and analyzed using frequency, percentage, t-test, analysis of variance and ${\chi}^2$. Results: The accuracy of chest compression was statistically significantly higher for SPCPR, 63.03%[${\pm}8.75$] for SPCPR and 55.50%[${\pm}10.17$] for TCPR [t=3.074, p=.003]. The depth of chest compression was statistically significantly greater for SPCPR, 4.51cm[${\pm}0.45$] for SPCPR and 4.16cm[${\pm}0.61$] for TCPR [t=2.503, p=.015]. The rate of chest compression was statistically significantly higher for TCPR, 105/min[${\pm}10.79$] for SPCPR and 111/min[${\pm}11.57$] for TCPR [t=-2.008, p=.049]. Accuracy of position of chest compression was statistically significantly higher for SPCPR, 96.10%[${\pm}13.73$] for SPCPR and 79.93%[${\pm}30.34$] for TCPR [t=2.659, p=.011]. Accuracy of full release was higher with SPCPR, with 86.30%[${\pm}30.53$] for SPCPR and 71.10%[${\pm}36.05$] for TCPR, but the difference was not statistically significant [t=1.762, p=.083]. Conclusion: Saddle position CPR was found to be more accurate than TCPR in the performance of manual head-up CPR.

• Corrosion Science and Technology
• /
• v.14 no.6
• /
• pp.288-295
• /
• 2015

The present work addresses crevice and galvanic corrosion processes occurring at the cylinder head gasket/cylinder head interface and cylinder head gasket/cylinder liner interface of four-stroke medium-speed diesel engines for marine applications. The contact between these systems and the marine environment can promote formation of demanding corrosion conditions, therefore influencing the lifetime of the engine components. The electrochemical behavior of various metals and alloys used as head gasket materials (both ferrous alloys and copper alloys) was investigated. The efficacy of corrosion inhibitors was determined by comparing electrochemical behavior with and without inhibitors. In particular, crevice corrosion has been investigated by electrochemical tests using an experimental set-up developed starting from the requirements of the ASTM G-192-08, with adaptation of the test to the conditions peculiar to this application. In addition to the crevice corrosion resistance, the possible problems of galvanic coupling, as well as corrosive reactivity, were evaluated using electrochemical tests, such as potentiodynamic measurements. It was possible to quantify, in several cases, the corrosion resistance of the various coupled materials, and in particular the resistance to crevice corrosion, providing a basis for the selection of materials for this specific application.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1875-1878
• /
• 2005

It is not efficient and scarcely out of the question to use commercial expensive electron beam lithography system widely used for semiconductor fabrication process for the manufacturing application field of various devices in the small business scope. Then scanning electron microscope based electron beam machining system is maybe regarded as a powerful model can be used for it simply. To get a complete suite of thus proper system, column unit build up with electron beam gun head unit is necessarily required more than anything else to modify scanning electron microscope. In this study, various components included ceramic isolation plate and main body which are essentially constructed for electron beam gun head unit are designed and manufactured. And this electron beam gun head unit will be used for next connected study in the development step of scanning electron microscope based electron beam machining system.

• Current Optics and Photonics
• /
• v.4 no.3
• /
• pp.221-228
• /
• 2020

We developed an all-fiber RGB laser light source module for application in an automobile head-up display. It is based on laser diodes and an optical fiber combiner that substantially enhances the flexibility of configuration and stability against harsh working conditions for automobiles. We coupled 13 laser diodes with optical fibers and merged them into a single output with a beam combiner device. Red (R), green (G), and blue (B) laser sources were employed to produce primary colors that were mixed into a white light output. An optical output power of approximately 1.5 W was achieved, and the color balance of the output lights was assessed based on the CIE 1931 color space. The optical output power was shown to be stable for over 160 h within an optical fluctuation of less than 0.27%.

• Journal of the Ergonomics Society of Korea
• /
• v.36 no.4
• /
• pp.293-303
• /
• 2017

Objective: This study aims to evaluate visual discomfort and visual fatigue caused by watching HMD and smartphones by conducting both subjective and objective measure. Background: With the rapid development of mobile Head-Mounted Display (HMD), the problem of visual discomfort and visual fatigue caused by watching Virtual Reality (VR) contents became a crucial concern for consumers and manufacturers, especially given that the casing of mobile HMD keeps the phone at a specified distance from the lenses that is close to the eyes. Method: Two smartphones were chosen for a preliminary study: LG G5 and Galaxy S7. As for a main study, iPhone 6S and Galaxy S7 were used. After being exposed to the selected clips, participants were asked to answer Simulator Sickness Questionnaire (SSQ) and went through optometric tests that measure tear break-up time, spherical equivalent, and contrast sensitivity. Results: The subjective assessments indicate that HMD causes more visual discomfort compared to watching a smartphone. Furthermore, the experimental result confirms that watching a HMD causes more eye dryness compared to smartphones. Conclusion: The result of the study compared visual discomfort and visual fatigue of two different displays, HMD and smartphone, and confirmed that watching HMD causes more visual discomfort and visual fatigue. Application: Ultimately, this study could help manufacturers understand the strengths and weaknesses of different display forms, providing guidance for an effective application of HMD.

• Korean Journal of Bronchoesophagology
• /
• v.17 no.1
• /
• pp.29-34
• /
• 2011

Traditionally, the main strategy of treatment of the head and neck cancer was en bloc resection including adjacent normal tissues through wide incision. However, the procedures may leave severe functional deficit such as swallowing difficulty, aspiration, and wide neck scar. Therefore, many attempts have been made up to minimize these morbidities. Of them, the minimal invasive approach such as transoral laser microsurgery (TLM) and transoral robot surgery (TORS) have been spolighted as a sensible strategy for organ preservation of the head and neck cancer patients. Results of TLM are equivalent to those obtained by conventional surgery, with considerably less morbidity, less hospital time and better postoperative function. Oncologic results of TLM are equivalent to conventional surgery. TORS are safe, feasible, and promising but oncologic safety is not yet verified. This article covers to current application of TLM and TORS, their advantages and limitations, and future direction.