• 한국미생물·생명공학회지
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• 제24권4호
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• pp.472-477
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• 1996

Natural human epidermal growth factor (nhEGF) was purified from pregnant human urine by benzoic acid adsorption, DEAE-Sepharose ion exchange, and immunoaffinity chromatography. The purified nhEGF was further separated into four fractions using Bondapak C$_{18}$ HPLC system. Following characterization by Western blot analysis and double immu- nodiffusion, we found that each fraction corresponds to four derivatives of the nhEGF. For biological analysis of nhEGF, we optimized the labeling time and serum concentration for the incorporatioin of 5-bromo-2'-deoxy uridine (BrdU), a non-radioactive alternative for [$^{3}$H]-thymidine uptake, into NIH 3T3 cells. The DNA synthesis of NIH 3T3 cells was gradually increased at the nhEGF concentrations between 0.1 - 10 ng/ml in the Dulbecco's Modified Eagles Medium (DMEM) containing 0.2% Fetal calf serum (FCS). When we assayed the biological activity of four fractions, the activity of the second fraction was superior to that of the others. Based on the results from the HPLC analysis spiked with recombinant human epidermal growth factor (rhEGF) and amino acid sequencing, we concluded that the second fraction was nhEGF and the other three fractions were the derivatives of nhEGF. In addition, the proportion of nhEGF was approximately 46% is compared with that of the other three derivatives.

• 센서학회지
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• 제21권2호
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• pp.114-120
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• 2012

This paper describes the design, fabrication and testing of a micromachined resonant accelerometer consisting of a symmetrical pair of proof masses and double-ended tuning fork(DETF) oscillators. Under the external acceleration along the input axis, the proof mass applies forces to the oscillators, which causes a change in their resonant frequency. This frequency change is measured to indicate the applied acceleration. Pivot anchor and leverage mechanisms are adopted in the accelerometer to generate larger force from a proof mass under certain acceleration, which enables increasing its scale factor. Finite element method analyses have been conducted to design the accelerometer and a silicon on insulator(SOI) wafer with a substrate glass wafer was used for fabricating it. The fabricated accelerometer has a scale factor of 188 Hz/g, which is shown to be in agreement with analysis results.

• 한국식품조리과학회지
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• 제21권6호통권90호
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• pp.867-876
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• 2005

The purposes of this study were, 1) to investigate the causal relationship between customer's life-style and motivation of eating-out, and 2) to research the causal nexus between motivation of eating-out and satisfaction of attributes to choose the restaurant. Reliability analysis, factor analysis, and Structure Equation Model(SEM) were adapted by Windows SPSS 10.0 and Amos 4.0. Life-style was divided into 7 factors and eating-out motivation into 5. Life-style influenced significantly each motivation of eating-out. It had positive influence on 'Reception and congratulation', 'Change of dietary life', 'Economic saving', "'Preference motivation', and 'Advertisement and companion's need', but negative influence on 'Reception and congratulation', 'Change of dietary life', and 'Preference motivation'. Customer's motivation of eating-out also influenced significantly the attributes. Factorl 'Reception and congratulation' had positive influence on all attributes except for 'Transportation convenience and distance to the shop'. Factor 2 'Change of dietary life' had negative influence on 'Food's taste, quantity, price', 'Sanitation and cleanness', and 'Staff's service quality' Factor 3 "Economic saving' had positive influence on 'Food's taste, quantity, price' and 'Transportation convenience and distance to the shop'. factors 'Advertisement and companion's need' had positive influence on 'Atmosphere of restaurant' and negative influence on 'Food's taste, quantity, price'.

• Wind and Structures
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• 제31권6호
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• pp.575-591
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• 2020

Wind load is typically considered as one of the governing design loads acting on a structure. Understanding its nature is essential in evaluation of its action on the structure. Many codes and standards are founded on state of the art knowledge and include step by step procedures to calculate wind loads for various types of structures. One of the most accepted means for calculating wind load is using Gust Load Factor or base bending Moment Gust Load Factor (MGLF), where codes are adjusted based on local data available. Although local data may differ, the general procedure is the same. In this paper, ASCE 7-16 (2017), which is used as the main reference in the U.S., and Korean Building Code (KBC 2016) are compared in evaluation of wind loads. The primary purpose of this paper is to provide insight on each code from a structural engineering perspective. Herein, discussion focuses on where the two codes are compatible and differ. In evaluating the action of wind loads on a building, knowledge of the dynamic properties of the structure is critical. For this study, the design of four figurative high-rise buildings with dual systems was analyzed.

• 방사성폐기물학회지
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• 제6권3호
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• pp.163-170
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• 2008

30 % TBP/NDD-2 M $HNO_3$ (0.005 M $K_2Cr_2O_7$ 함유) 계에 의해 산화 추출된 Np의 유기상을 대상으로 n-butyraldehyde (NBA)에 의한 Np의 환원 역추출을 고찰하였다. Np의 역추출은 NBA의 농도 증가에 따라, 역추출 수용상 내 질산농도 감소에 따라, 그리고 반응 온도 감소에 따라 증가하였으며, 이때 겉보기 환원 역추출 속도식은 $-d[Np]_{Org.}/dt$ =1,524 exp(-2,906/T) $[NBA]^{0.91}\;[H^+]^{-0.92}[Np]_{Org.}$. 이었다. 1.04M NBA 및 2M $HNO_3$에서 Np 및 U의 역추출률은 각각 70.1 % 및 7.1 % 이며 이때 분리계수(($=D_U/D_{Np}$)는 30.4 정도로, TBP-$HNO_3$ 계에 의해 공추출된 Np과 U은 NBA에 의해 효과적으로 상호 분리할 수 있음을 알 수 있었다.

• Ocean and Polar Research
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• 제36권3호
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• pp.255-276
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• 2014

The dispute between China and Japan regarding $Di\grave{a}oy\acute{u}t\acute{a}i$ is believed to be quite similar to the controversy surrounding Dokdo in terms of historical and post-war processes except for the point that the phenomena of occupation is different with regard to Dokdo. China's claim to $Di\grave{a}oy\acute{u}t\acute{a}i$ is based on historical title and continuous use while the basis of Japan's claim is summarized as preoccupancy of ownerless land. Even though Japan acknowledges that China discovered $Di\grave{a}oy\acute{u}t\acute{a}i$, Japan claims that the act to establish sovereignty over the island from the standpoint of International Law was not taken by China. However, at that time, effective occupation was not an essential prerequisite for the acquisition of a territory. That is to say, from a legal perspective, the legal right for an area could be established based on the discovery of the land, and so it is thought that Japan is applying the current criteria of International Law in a manner that is inappropriate. When we review the post-war process, the San Francisco Peace Treaty does not directly mention $Di\grave{a}oy\acute{u}t\acute{a}i$. But based on the said treaty, we can note that Japan gave up all rights for the southern area that is north of the boundary line that equates to latitude $29^{\circ}$ and that includes the Ryuku Islands and $Di\grave{a}oy\acute{u}t\acute{a}i$. Of course, the provisions for the territory in the San Francisco Peace Treaty and its disposal are not the final factor for the judgment regarding dominium of $Di\grave{a}oy\acute{u}t\acute{a}i$. However, it seems clear that Japan's attitude and interpretation regarding the issues of $Di\grave{a}oy\acute{u}t\acute{a}i$, the Kuril Islands and Dokdo is problematic.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2000년도 7월 학술대회지
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• pp.86-87
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• 2000

In this paper, we discuss why two different surface forms appear in loanwords for English and German /${\int}$/ In Korean, a vowel is inserted into loanwords if a consonant cannot be properly syllabified. Therefore, /${\int}$/ in some positions of loanwords trigger vowel insertion. Interestingly, /${\int}$/s in the onset cluster of English and German words were borrowed in Korean as Iful with the inserted vowel [u] whereas If Is in the coda position of English and German words were borrowed as Ifil with the inserted vowel [i]. For example, 'shrimp' is adopted as [${\int}urimphi$] whereas 'rush' is adopted as [$ra{\int}i$]. In this paper, we attempt to find out the phonetic reason for the distribution of the surface forms of /${\int}$/. We assume that since the formant frequency of [i] is higher than that of [u], the peak frequency of /${\int}$/ with the surface form of [${\int}$i] in loanwords may be higher than that of /${\int}$/ with the surface form of [${\int}u$]. We also assume that duration may be another factor for the distribution of [${\int}i$] and [${\int}u$]. Since /${\int}$/ and /u/ use lip rounding whereas /i/ doesn't, the duration for [${\int}i$] might be longer than that of [${\int}u$]. German supports our assumption. /${\int}$/ in the onset cluster is longer than /${\int}$/ in the coda position. It also has higher peak frequency than that of /${\int}$/ in the coda position. In loanwords, ${\int}$ in the onset cluster is borrowed as [${\int}u$] as in Spiegel whereas /${\int}$/ in the coda position is borrowed as [${\int}i$] as in Bosch. English, however, does not support our assumption. Peak frequency of [${\int}$] depends on the preceding vowel, not on its position in the syllable structure. If the preceding vowel is front, then the peak freuency of the following of the following /${\int}$/ is high but if the preceding vowel is back, than the peak frequency of the following /${\int}$/ is low. The peak frequency of /${\int}$/ in the onset cluster seems to be in between. As we assumed, however, the duration of /${\int}$/ in the coda position is longer than of /${\int}$/ in the onset cluster. With the mixed results, we question whether Koreans really hear two different xounds for /${\int}$/ in English words. For the future experiment, we would like to perform the perception tet for /${\int}$/ in English words.

• 한국지반공학회논문집
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• 제25권1호
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• pp.77-88
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• 2009

본 연구에서는 부산지역 점토의 비 배수전단강도를 추정하기 위해 현장 및 실내시험을 통해 부산점토의 콘계수를 평가하였다. 이를 위해 부산신항 지역 및 녹산지역에서 $CK_0U$ 삼축압축시험, 베인전단시험, 피에조 콘 관입시험(CPTu) 등을 실시하였다. 시험결과, 현장 점토의 비배수전단강도는 심도에 따라 증가하였으며, 강도증가비는 각각 $S_{u(CKU)}/{\sigma}'_v\;{\fallingdotseq}\;0.26{\sim}0.44$와 ${\mu}_{su(VST)}/{\sigma}'_v\;{\fallingdotseq}\;0.20{\sim}0.23$로 삼축 비배수전단강도가 베인 비배수전단강도에 비해 1.5배 정도 크게 나타났다. 또한 CPTu 시험결과 콘선단저항($q_c$)과 간극수압($u_2$)은 심도에 따라 증가하였으며, 간극수압비($B_q$)는 $0.3{\sim}1.0$정도로 나타났다. 삼축압축 및 베인시험 결과와 CPTu 결과로부터 콘계수를 산정한 후 간극수압비와 비교한 결과, 삼축 비배수전단강도와 베인 비배수전단강도를 추정하기 위한 부산지역 점토의 콘계수는 각각 $5{\sim}20$, $10{\sim}35$로 나타났다. 그리고 콘계수는 간극수압비가 증가함에 따라 선형적으로 감소하였으며, 이로부터 간극수압비를 이용한 부산점토 콘계수 추정방법을 제안하였다.

• 대한기계학회논문집B
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• 제26권8호
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• pp.1095-1101
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• 2002

An experimental apparatus was prepared to investigate thermal and hydrodynamic characteristics of regenerator at cryogenic temperature under pulsating pressure condition. The regenerator was pressurized and depressurized by a compressor with various operating frequencies. Cold end of the regenerator was maintained around 100 K by means of a liquid nitrogen heat exchanger. Instantaneous gas temperature and mass flow rate were measured at both ends of the regenerator during the whole pressure cycle. Pulsating pressure drop across the regenerator was also measured to see if it could be predicted by a friction factor at steady flow condition. The operating frequency of pressure cycle was varied between 3 and 60 Hz, which are typical operating frequencies of Gifford-McMahon, pulse tube, and Stilting cryocoolers. First, the measured friction factor for typical wire screen mesh regenerator was nearly same as steady flow friction factor for maximum oscillating Reynolds number up to 100 at less than 9 Hz. For 60 Hz operations, however, the discrepancy between oscillating flow friction factor and steady flow one was noticeable if Reynolds number was higher than 50. Second, the ineffectiveness of regenerator was directly calculated from experimental data when the cold-end was maintained around 100 K and the warm-end around 293 K, which simulates an actual operating condition of cryogenic regenerator. Influence of the operating frequency on ineffectiveness was discussed at low frequency range.

• 대한치과기공학회지
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• 제30권2호
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• pp.105-119
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• 2008

This study explored the status of free time activities among the dental technicians who are working at Seoul, Gyonggido, and Gangwondo. On the basis of this research, we aim to present needs and applicable solutions to improve the working conditions and enhance the quality of life through more effective time management in free time activities that lead to their self development and far more enriched life. 500 subjects were randomly chosen and the questionary sheets were provided. Among them, 305 sheets were returned to be analysed through SPSS Win 10.0 software and the results are as follows; First, mean in the satisfaction of leisure activities was 3.44(SD=.73). Mean in sub categories was as follows; psychological factor(M=3.65, SD=.71), social factor(M=3.54, SD=.75), rest factors(M=3.52, SD=.63), physical factor(M=3.43, SD=.88), other factors(M=3.40, SD=.66), circumstantial factor(M=3.33, SD=.63), educational factor(M=3.24, SD=.73). Second, the most relevant sub categories in the satisfaction of leisure activities were social, educational, physical, and other circumstantial factors by sequence. Factors that affect leisure activities satisfaction were career and status of health, which shows statistical significance(p<.001). That is to say, contention of this study is that the general characteristics are closely related with and affect the types and the level of satisfaction in leisure activities of the subjects. Considering these results, the dental businesses and the associations of dental technicians should recognize the needs to improve the time management through more efficient cooperations between dentists and back office dental team, systemized working time, and introduction of incentive system among others. On the basis of this appreciation, the dental business should provide more time and various opportunities with the dental technicians. Dental technicians also need to reconsider their appreciations of leisure activities, that is, leisure activities are not just spending time doing something but they refresh them and enable them to be more active and faithful to home and work.