• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.31 no.7 s.262
• /
• pp.596-603
• /
• 2007

As increasing interest for soot emission. etc in combustion systems, various studies are being carried out for the reduction and measurement techniques of soot. Especially, laser induced incandescence is the useful measurement technique which has distinguished spatial and temporal resolution for primary particle size, volume fraction and aggregated particle size etc. Time resolved laser induced incandescence is the technique for measuring primary particle size that is decided to solve the signal decay rate which is related to the cooling behavior of heated particle by pulsed laser. The cooling behavior of heated particle is able to represent the heat and mass transfer model which are involved constants of soot property for surround gas temperature on the our previous work. In this study, it is applied to the time-dependence thermodynamic properties for soot temperature instead of constants of soot property for surround gas temperature and compared two different model results.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.45 no.2
• /
• pp.95-102
• /
• 2008

This paper proposes an adaptive speech enhancement system based on an auditory system to enhance speech that is degraded by various background noises. As such, the proposed system detects voiced and unvoiced sections, adaptively adjusts the coefficients for both the lateral inhibition and the amplitude component according to the detected sections for each input fame, then reduces the noise signal using a time-delay neural network. Based on measuring the signal-to-noise ratio, experiments confirm that the proposed system is effective for speech degraded by various noises.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.20 no.5
• /
• pp.728-737
• /
• 1996

The purpose of this study is to investigate the change of the chemical properties of wool treated with six kinds of alkali (NaOH, Naac03, NH40H, NH2CH3CH30H, TMAH and BTMAH) with or without CTAB. Content of bound fatty acid liberated from wool surface, elemental composition and allw6rden time were measured to compare the surface modification of untreated and alkali treated wool. Also, the chemical degradation of the fiber was investigated by measuring cystine contents and urea-hydrogensulfite solubility. The result were as follows: 1. By the alkali treatment of wool, the covalently bound fatty acid of the epicuticle was removed and the allworden time was shortened, and in the case of wool treated with TMAH, BTMAH, the allw6rden sacs were formed unevenly and rarely. Also, cystine contents and urea-hydrogensulfite solubility were decreased by alkali treatment on wool. 2. The modification of epicuticle and the chemical degradation of wool were occurred due to alkaline hydrolysis in the order of TMAH, BTMAH > NaOH, Na3c03> NH2CH3CHaOH, NH40H. 3. As a treating time increased, the modification of epicuticle and chemical degradation of wool were accelerated. By the addition of CTAB to the alkali solution, the modification of epicuticle was increase, and the cystine contents and urea-hydrogensulfite solubility were reduced than that of wool teated with alkli without CTAB due to reduction of negative charge on the wool surface by the adhesion of CTAB.

• Archives of Plastic Surgery
• /
• v.33 no.5
• /
• pp.676-679
• /
• 2006

Purpose: Breast volume is one of the crucial measurements in preoperative planning and postoperative evaluation of the results in mammoplasty. There are several methods suggested by different authors, but there is still no commonly accepted standard methods for measuring breast volume. To help the surgeons to base their estimation on an objective evaluation, we developed a simple method using Polyethylene bag and plaster molding. Methods: After Polyethylene bags were put in suitable size on both breasts of the patient in upright position, silk plaster was molded on the surface evenly. Then molds can be obtained after marking boundaries of breasts with a pen. Breast volume measurement can be done by filling water in the molds and measuring it. Moreover, postoperative design for natural skin brassier was possible using the molds. Results: This method was applied to 2 patients for reduction mammoplasty and the breast volume measurement was simple, hygienic and accurate, done within 10 minutes. Conclusion: This method using Polyethylene bag and plaster molding has several advantages. 1. It is comparatively accurate regardless of the size and shape of patient's breasts in upright position. 2. Measurement time is short and inconvenience and shame of patients can be reduced by making molds after putting on Polyethylene bags. 3. It is relatively economical and uses easily available hygienic materials. 4. The postoperative shape and volume of breasts can be predicted by using molds preoperatively.

• Journal of Climate Change Research
• /
• v.9 no.4
• /
• pp.377-384
• /
• 2018

The chamber method is widely used for measuring methane emission from paddy rice fields. The closed static chamber has advantages of easy installation and removal in the field and low manufacturing cost. However, the manual chamber method requires a lot of labor and has a limited sampling time and frequency. To overcome the disadvantages of the manual chamber, the auto-chamber system is used for measuring methane emission. We compared the differences in methane flux between the auto-chamber and manual chamber. To investigate methane emissions by the two methods, a chamber was installed for each of the following treatments : control without rice straw (NA), spring plowing after autumn rice straw application (SPRA) and autumn plowing after autumn rice straw application (APRA). The total methane emission was lowest in the control and highest in APRA with both methods. There was no significant difference in total methane emission between the methods, but dynamic fluctuation in methane with temperature change was accurately measured in the auto-chamber. Measuring methane emission with an auto-chamber system is expected to reduce uncertainty and increase accuracy, accompanied by labor reduction.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.14 no.1
• /
• pp.157-171
• /
• 1990

The heat transfer problem associated with pulse technique for measuring thermal diffusivity was solved by means of Green function. The obtained general solution was discussed so as to apply for all possible cases; kinds of boundary condition and heat source, irradiation positions of heat pulse, radius of heat pulse, one-and two-dimensional heat flow, finite pulse time effects and radiation heat loss systems. Experimentally, the laser flash lamp was used as heat source for measuring thermal diffusivity of low carbon, aluminium chilled steel plate, which was heavily rolled in order to measure the variation of thermal diffusivity in the temperature range from room temperature through 500.deg. C. The derived results are (1) materials produced from same furnace showed a somewhat different thermal diffusivity values. (2) the thermal diffusivity value of rolled material was smaller than unrolled material and the difference decreased as increasing temperature. (3) the thermal diffusivity value of an annealed and temper rolled material was larger than the value of a cold rolled material, even thought smaller than unrolled material. (4) In case of heavy rolled material, there was no consistent relationships between the thermal diffusivity and the reduction in thickness.

• Journal of the Korea Society of Computer and Information
• /
• v.8 no.4
• /
• pp.75-80
• /
• 2003

In this paper, we designed add current scan system basically. Although NDT system using AC method in now days had problem with limit of detection rate and limit of device organization, in this paper, we made up these problem so that designed device smaller than system used, reduction of cost of system organization and precision of measuring crack. Also, AC leakage flux system had high accuracy about minute crack in the surface and advantage of designing system easily so that we designed system for concerning about crack of surface. Furthermore, it can be able to detect exact crack of reference in wide area by using DSP320C31 chip to reduce the time of measuring crack.

• KIEAE Journal
• /
• v.15 no.5
• /
• pp.107-112
• /
• 2015

Purpose: This study desires to investigate an effect of indoor temperature, humidity, and illuminance targeting a planting system of double-skin facade and cavity space adjacent to the outside within a certain period of winter. Through this, the study suggests a basic material about an energy conservation effect of double window system using planting to reduce heating load of a building in winter, so desires to contribute to indoor thermal comfort effect and illuminance correction study of double window and indoor plant. Method: Considering effects such as day and night climatic elements and air conditions in winter, illuminance measurement was conducted through a double-skin facade of space, a subject of the measurement, on the basis of practical residence time of a resident, and this study analyzed characteristics of indoor illuminance about this. The study measured and compared a change of insolation, dry-bulb temperature, and relative humidity at each indoor-outdoor measuring point, so measured and compared characteristics of an indoor temperature effect by elements of double-skin facade and indoor plant. Result: Through this study, the researcher could determine that indoor plant within double window in winter not only blocks solar radiation but also photosynthesizes, so is somewhat disadvantageous to winter thermal comfort reducing heating load. In addition, solar radiation going through interior plays a role to bring down somewhat high humidity to about 50% of reasonable humidity, so plays a direct role of maintenance of comfortable indoor space. Although there are effects such as blocking of solar radiation and temperature reduction, this has a positive influence on humidity control and proper illuminance distribution. The researcher could determine that illuminance, temperature, and humidity by solar radiation penetration for the whole measuring time play a role to supplement indoor environment mutually.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.10 no.4
• /
• pp.71-77
• /
• 2011

In this paper, we propose a conversational quality measurement (CQM) system for providing the objective QoS of high quality mobile VoIP voice telecommunication. For measuring the conversational quality, the VoIP telecommunication system is implemented in two smart phones connected with VoIP. The VoIP telecommunication system consists of echo cancellation, noise reduction, speech encoding/decoding, packet generation with RTP (Real-Time Protocol), jitter buffer control and POS (Play-out Schedule) with LC (loss Concealment). The CQM system is connected to a microphone and a speaker of each smart phone. The voice signal of each speaker is recorded and used to measure CE (Conversational Efficiency), CS (Conversational Symmetry), PESQ (Perceptual Evaluation of Speech Quality) and CE-CS-PESQ correlation. We prove the CQM system by measuring CE, CS and PESQ under various SNR, delay and loss due to IP network environment.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.7 no.9
• /
• pp.97-104
• /
• 1999

Brake squeal noise has been a problem since the early days of motoring . It is important to obtain vibration mode shape for reduction of brake noise . Stroboscopic Electronic Speckle Pattern Interferometry is a very powerful measuring method for study of vibrating objects in static state compared with conventional methods because this method can give both resonance frequency and quantitative visualization of vibration mode shape at the same time. In this paper, we performed qualitative visualization and quantitative analysis of vibration mode shpae of disk brake by using stroboscopic ESPI and phase shifting method. The stroboscopic wavefronts are obtained by chopping continuous wave laser beam using acousto-optic modulator .Experiments were performed at the same constraint conditions as disk brake of the practical vehicle as far as possible. The experimental results of this paper show quantitative measurement of vibration mode shape and quantiative visualization of vibration amplitude of disk brake with 3D plotting.