• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.3
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• pp.384-392
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• 1997

Potassium lithium niobate(KLN) single crystal for a nonlinear-optic material, which changes the wavelength of lasers, has a ferroelectric tetragonal tungsten bronze structure at room temperature. It has been very hard to get single crystals of good quality due to the cracks during cooling process. In order to investigate the composition change due to the evaporation of solution during the growth, the thermogravimetric analysis was carried out. In atmospheric condition at $1000^{\circ}C$ which is about $10^{\circ}C$ higher than the crystal growing temperature, the weight change was negligible amount of $1.46{\times}10^{-5}$g/($\textrm{cm}^2$hr). By using both the Pt plate as the nucleation site and the slow cooling method with temperature fluctuation, KLN single crystal of good quality of size 1 cm could be obtained. The phase transition temperature was $490^{\circ}C$, which was higher than that reported by other researchers of the other composition. The optical anisotropy due to the absorption of OH-band exists in the range of IR.

• Journal of Families and Better Life
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• v.27 no.6
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• pp.155-169
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• 2009

Resident participation plays much of a rule to the cohousing, which is organized independently and has the characteristics of community life, especially in the initial state of cohousing process. However, it is hard to realize the resident participation in proper order due to lack of a personal time, individual effort and an insufficient knowledge related with cohousing. So, it is thought that the guidance of cohousing expert and coordinator is needed to enable the residents to perform in an active attitude. The development of educational program and workshop connected with resident participation is also accompanied. In this study, to make the positive and systematic participation of cohousing residents, we established the workshop program and performed workshop with our developed program, based on preceding researches and examples. We selected the object of workshop as five housewives in thirties and forties. Workshop was consisted of six process steps. (1) Introduction and question of workshop and cohousing (2) examining and arranging the opinion (3) Master plan of cohousing village (4) Planning of common living space (5) Planning of individual living space (6) Analysis of final results and evaluation of workshop. The workshop held six times and it took about five~six hours per each meeting. Workshop participants expressed their opinion actively and attended in a positive manner in order to the design of their desired village and cohousing. During workshop process, the players established the common target of their village by means of life card, target card game. Also, based on the common target, the layout of village was planned using a collage game and card arrangement game. By workshop activity, the members started to recognize the significance of participation on the drawing board and improve their technique of communication and decision-making. Furthermore, workshop process made it possible to approach the concrete forms of their cohousing village. Especially, in the closing phase, the participant satisfaction about workshop and cohousing is increased suddenly and expressed their intention to join the real workshop related with cohousing.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.6
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• pp.591-597
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• 2001

Ti alloy is used for essential parts of aircraft for high temperature environment. Although Ti alloy has excellent performance in regard to mechanical properties, it is difficult ot find fatigue cracks by nondestructive ultrasonic inspection due to its two-phase microstructure, which consists of hard alpha and beta phases. Sound energy reflected from microstructural features in the component produces a background inspection noise which is seen even when no defects are present. This noise can inhibit the detection of critical internal defects such as pores cracks or inclusions. To obtain fundamental data on ultrasonic inspection of Ti alloy, ultrasonic testing was performed using a specimen with small drill holes and ultrasonic wave propagation velocites were measured.

• Journal of the Korean institute of surface engineering
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• v.31 no.6
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• pp.334-344
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• 1998

Yew coating pmccss t.o form a surface layer ol CrN phasc on mild steel (A81 1020!, AlSI Hi3, 1Cr-0.5Mo steel (ASTM A213 and Nickrl-base superalloy (Inconel 718) was developed. Surlaces of various alloys t,n.ateii by chromizing for the formation ol Cr diffusion layer was subsequently trcaled by plasma nitriding in order t.o form the hard CrS coating layer on the surfaces. This duplex plasma surface tri-atments of chromizing and plasma nitriding have induced a lormation of a duplex-lrcated surfacr hyer of approximat~ls 70-80 $\mu\textrm{m}$thickncss with a iargcly improved microiiardnrss up to approxiniateW 1500Hv(50gf). The main cause for the lage improvment in the surface hardncss is altribilted to [.he fact that CrN and $Fe_xN$ phases are created successfully by ccliromizins and plasma nilriding treatment. High tenipera1,urc wear resislance of the duplex-treated mild steel and HI3 steels at $600^{\circ}C$ was examined. Comparing the duplex-treated specimens with the specimens treated only by chromizing, the rcsults shovmi that, thc wear volume of the duplex-treated mild skcl and 1113 stcel aSt.er a wear test, at $600^{\circ}C$ were reduced hy a Iactor of 8 and 3, respectively. Characteristics of the CrS phase by duplrx treatment were compared with $CrN_x$,/TEX> film by ion plating and the wear behaviors of CrN film lormed by two different nroccsses arc nea.riy identical.

• Journal of the Korean Ceramic Society
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• v.42 no.9 s.280
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• pp.618-623
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• 2005

HTGR (High Temperature Gas-Cooled Reactor) is highlighted to next generation power plant for producing the clean hydrogen gas. In this study, the spherical $UO_2$ kernel via $UO_3$ gel particles was prepared by the sol-gel process. Raw material of slightly Acid Deficient Uranyl Nitrate (ADUN) solution, which has pH = 1.10 and $[NO_3]/[U]$ mole ratio = 1.93, was obtained from dissolution of $U_3O_8$ powder with conc.-$HNO_3$. The surface of these spherical $UO_3$ gel particles, which was prepared from the broth solution, consisted of 1 M-uranium, 1 M-HMTA, and urea, were covered with the fine crystallite aggregates, and these particles were so hard that crushed well. But the other $UO_3$ gel particles prepared with the broth solution, consisted of 2 M-uranium, 2 M-HMTA, and urea, have soft surface characteristics and an amorphous phase. This type of $UO_3$ gel particles is some chance of doing possibility of high density from the compaction. The amorphous $UO_3$ gel particles was converted to $U_3O_8$ and then $UO_2$ by calcination at $600^{\circ}C\;in\;4\%\;-\;H_2\;+\;N2$ atmosphere.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.141-146
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• 2008

As the interest about ubiquitous environment is increasing, there are many researches about the services in this environment. These services have important issues in interpreting the users' context, using many kinds of sensors, like PDA, GPS and accelerometers. Low level raw data, which sensors like accelerometers calibrates, are hard to use, and to provide real-time services preprocessing and interpreting the data into context, in real-time, is important. This paper describes a context integrate system which can integrate these sensors and also sensors which has raw data, like accelerometers and physiological sensors, and define the context interpret rule with XML. The proposing system reduces programming operations when adding a sensor to the sensor network or modifying the context interpreting rule by using XML. By using this system, we implemented a real-time data monitoring system which can describe the numeric data into graphs, and assist the user to validate the data and results of the preprocess phase, and also support the external services and applications to use the context of the user.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.505-508
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• 2008

It's hard to express a lot of information within the drawings and the specifications as construction projects have gradually become large-size and complex. So, disputes are caused by that and reason that the usual practice(culture) of contract of the constructions in Korea is based on unfair rather than the fair principle between clients and contractors. However, the contractors don't try to solve this kind of things because they are worried about at their disadvantage situation. Therefore, this paper deduced the factors in the pre-dispute phase by analysing the cases of the civic counseling in the office of supply and the pre-dispute factors, and conduct analysis on the factors' importance by using AHP. The results will be used for a check-list to prevent the disputes.

• Journal of Broadcast Engineering
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• v.16 no.6
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• pp.1026-1035
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• 2011

This paper presents generalization and application for the conventional SISO decoding algorithm of Block Turbo Codes. R. M. Pyndiah suggested an iterative SISO decoding algorithm for Product Codes, two-dimensionally combined linear block codes, on AWGN channel. It wascalled Block Turbo Codes. Based on decision of Chase algorithm which is SIHO decoding method, SISO decoder for BTC computes soft decision information and transfers the information to next decoder for iterative decoding. Block Turbo Codes show Shannon limit approaching performance with a little iteration at high code rate on AWGN channel. In this paper we generalize the conventional decoding algorithm of Block Turbo Codes, under BPSK modulation and AWGN channel transmission assumption, to the LLR value based algorithm and suggest an application example such as concatenated structure of LDPC codes and Block Turbo Codes.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.5 no.2
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• pp.137-146
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• 1995

Twenty(20) large commercial buildings located in Seoul with friable sprayed-on surface insulation material on ceilings were investigated for asbestos content in bulk material by polarized light microscopy and for airborne fiber concentrations in buildings by phase contrast microscopy. In addition, such building-related variables as building age, numbers of traffic, airflow, surface conditions of the ceiling, temperature, and humidity were studied for any correlation with airborne fiber concentrations. The results were as follows: 1. Chrysotile asbestos was found in two bulk samples with 3-5% content and with <1%in one sample out of total 20 bulk samples collected. Glass fiber and mineral wool were the two major constituents of the bulk samples. 2. The ceiling surfaces were very friable in 16 buildings and were relatively hard in 4 buildings. The friability of the surface material was dependent upon the type and the amount of binder that had been mixed with the sprayed-on surface material. 3. Airborne fiber concentrations were log-normally distributed and the geometric mean(geometric standard deviation) fiber concentrations in the underground parking lots, inside buildings, and outdoor ambient air were 0.0063(1.97)f/cc, 0.0068(2.29)f/cc, and 0.0033(2.36)f/cc, respectively. 4. No significant relationship of airborne fiber concentrations and all building-related variables studied except humidity was found. The results of this study suggest that the sprayed-on surface insulation material found in some commercial buildings may possibly be contaminated with asbestos. Since most of the ceiling surfaces surveyed were very friable and poorly maintained and the airborne fiber concentrations were relatively high, there is a possibility of asbestos fiber contamination in these buildings, particularly at those buildings with asbestos-contaminated surface material. Since poorly maintained surface conditions were thought to be a source of high airborne fiber concentrations, there is a urgent need of a systematic operation and maintenance program. Further study of non-occupational asbestos exposure in general population utilizing advanced analytical technique such as transmission electron microscopy is highly recommended.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.442-445
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• 2002

Construction delay claim occurs more often than any other claim. Delay claim impacts adversely the company's existence as well as the project's monetary problem. Because the calculation of the delay is not quantitative, owing not to have enough evidence, it is hard to solve evenly the delay claim. So, it is need to cumulate structurely the construction data or evidence during the construction. This study considers the established study about construction delay claim database and the problems and then presents the relation method between phase schedule and database. Finally, this study established the productivity claim database modeling for construction project through conceptual database modeling and logical database modeling based on information needed to make construction productivity database. So. the purpose of the study is to establish the datamodel for productivity management of construction project for calculating the delay days considering the lost productivity.