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The Effect of indoor illuminance depends on direction of the side windows lighting (측창채광의 방향에 따른 실내조도의 영향)

  • Cho, Shee-Man;Kim, Won-Joong;Jang, Woo-Jin
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.05a
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    • pp.253-260
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    • 2004
  • 실내의 조명은 자연채광방식과 인공조명으로 나누어지는데 자연형 채광방식에서도 측창채광과 천창채광, 정 측창채광 그리고 반사 채광방식이 있다. 측창채광은 벽면에 대하여 일반적으로 연직인 창에 의한 채광을 말한다. 측창채광의 방향에 따라 실내조도는 영향을 많이 받는다. 따라서 본 연구는 측창채광의 동서남북의 방향에 따라 봄, 여름, 가을, 겨울의 계절에 따라 아침, 점심, 저녁시간대에 따라 변화되는 실내조도를 알아보았다. 실험방법은, 조명시뮬레이션 프로그램인 Lightscape V3.2를 사용하여 교실공간의 치수와 작업면의 높이를 가로 5.8[m], 세로 10.8[m], 높이 3[m], 작업면의 높이 0.75[m]로 정하였고, 각 시설물의 반사율[p]은 벽 80%, 창문 12%, 출입문 13%, 바닥 20%, 천장 85%로 지정하였으며 창문의 투과율은 88%로 설정하였다. 본 연구에서 측정하고자 하는 변수 값은 계절은 여름을 6월20일, 겨울은 1월20일 기준으로 하고 시간대는 09시, 13시, 18시로 하였으며 창측방위는 동, 서, 남, 북으로 정하였으며 계절과 시간은 가장 차이가 많이 나는 값을 선택하였다. 결론으로 창이 남쪽일 때 평균조도가 9,100[lx]로 가장 높았고, 시간별로는 점심에 19,590[lx]로 조도가 가장 높은 것을 알 수 있었고 조도 균제도는 창이 동쪽일 때 겨울에 가장 높았다. 창이 북쪽일 때는 여름이 겨울보다 평균조도가 약간 높았고, 시간별로는 아침에 조도가 약간 높은 것을 알 수 있었고 전체적으로 북쪽 창에서 실내조도가 현저하게 떨어지는 것을 알 수 있었다. 이와 같은 결과로 측창의 브라인드를 현재 사용하고 있는 수직 브라인드 대신에 수평 브라인드를 사용하여 주광의 범위를 넓게 조절하여 사용하게 하고, 점등제어를 현재 측창면과 수직으로 되어있는 배열을 수평으로 한다면 자연채광의 효과를 배가 할 수 있으리라고 사료된다. 미백 전, 미백후, 재광화 후 미세경도 변화 양상이 미백을 하지 않은 대조군과 차이를 보이지 않았으며 (p > 0.05) 미백 전과 미백 후의 미세경도의 차이 미백후와 재광화 후의 미세경도의 차이도 유의할 만한 차이가 없었다 (p > 0.05). 따라서 시중에 판매되고 있는 whitening strip과 미백 젤은 14일 동안의 통상적인 미백과정 동안 법랑질의 미세경도에 영향을 미치지 않는 것으로 사료된다.able pitch와 helical angle보다는 근본적으로 radial land가 screw-in effect의 예방에 더 큰 역할을 하는 것으로 추정될 수 있다 따라서 NiTi file의 사용 경험이 없는 초심자의 경우 근단부 폭경의 유지능력이 좋은 ProFile$^{(R)}$의 사용이 추천된다.)되었다.였으나 강남콩군 외에는 단백질의 소화 흡수율 및 효율은 크게 향상되지 않아 단백질의 소화 흡수율을 떨어뜨리는 요인에 관한 연구가 집중적 으로 이루어져야 하리라고 생각된다.면 바로 위 지점의 풍속을 측정하였다. 각 Seeding 물질에 대해 팬을 켜지 않았을 때, 즉 바람의 영향이 없을 때 측정한 표면유속을 바람의 세기가 변한 경우의 기준 표면유속으로 이용하였다. 본 연구의 결과 비중이 0.01 내외인 Ecofoam과 white polystyrene에 비해 비중이 0.92인 black polypropylene은 대부분이 물속에 잠겨 있어 흐름과 거의 일치하여 움직임을 알 수 있었다. 또한 흐름의 평균유속이 0.165 m/s의 저유속에서 바람이 tracers에 미치는 영향이 평균유속 0.558m/s인 경우보다 커서, 바람의 세기의 증가에 따라 표면유속 측정값이 급속히 감소되었다. 흐름의 평균유속이 큰 경우에는 바람이 tracer에 마치는 영향이 현격히 줄어듬을 보이고 있다. 결론적으로 유속이 증가함에 따라 바람의 영향은 감소하나, 바

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Investigation of Various Radiation Proton Energy Effect on n, p Type Silicon by Positron Annihilation Method (양전자 소멸 측정법으로 양성자 조사에너지 변화에 대한 n, p형 실리콘 구조 특성)

  • Lee, Chong Yong
    • Journal of the Korean Vacuum Society
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    • v.22 no.6
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    • pp.341-347
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    • 2013
  • The n-type and p-type silicon samples were exposed by 40.0, 3.98 MeV proton beams ranging between 0 to $20.0{\times}10^{13}protons/cm^2$. Coincidence Doppler Broadening Positron Annihilation Spectroscopy (CDBPAS) were applied to study of defect characteristics of p type and n type silicon samples. In this investigation the numerical analysis of the spectra was employed to the determination of the shape parameter, S, defined as the ratio between the amount of counts in a central portion of the gamma spectrum and the total counts of whole gamma spectrum. The S-parameter values strongly depend on the irradiated proton beam that indicated the defects generate more, rather than the energy intensity. 40 MeV irradiated proton beam in the n-type silicon at $20.0{\times}10^{13}protons/cm^2$ was larger defects than 3.98 MeV irradiated proton beam. It was analysis between the proton irradiation beams and the proton intensities of the irradiation. Because of the Bragg peak, SRIM results shows mainly in a certain depth of the sample to form the defect by the proton irradiation, rather than the defects to appear for the entire sample.

Applying Problem-Based Learning in University Business English Classes (비즈니스 영어수업에서 문제중심학습 적용의 유용성 탐색)

  • Kim, Bu-Ja
    • Journal of Digital Convergence
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    • v.13 no.2
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    • pp.91-103
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    • 2015
  • This research aimed to investigate the benefits of incorporating Problem-Based Learning(PBL) approach in Business English classes in a Korean university. This study focused on student experiences of learning in a PBL environment. The study examined the feasibility of cultivating students' key job competencies, that of their learning achievement and their satisfaction with the PBL approach. Data on student experiences were gathered from questionnaires. The analysis of the data showed, first, that the PBL could cultivate students' key job competencies. Second, the PBL could have a positive effect on students' acquisition of business content knowledge and their English language development. Third, the PBL approach achieved above moderate level of student satisfaction.

FTIR and Moisture Effects on Optical Information Transfer at Interface of Air and Glass (공기-유리 계면에서 광학정보 전달에 미치는 불완전 반사 및 수분 효과)

  • Han, Won Heum;Han, Ji Heum;Kim, Jee Hyen;Jung, Hyung Sik;Lee, Moon Ho
    • Journal of Adhesion and Interface
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    • v.13 no.2
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    • pp.73-84
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    • 2012
  • The transfer mechanism of optical information at the interface of air and glass (the air-glass IF) has been investigated by thoroughly fulfilling the theoretical and experimental analyses regarding the FTIR (Frustrated Total Internal Reflection) and moisture effects on the fingerprint onto a glass cup with water. As for the fingerprint onto a glass cup with water its image was observed to be very vivid, which turned out to be due to the difference between the two light intensities reflected on the air-glass IF and the wet fingerprint ridge by manipulating the optical theories such as Fresnel relation, Snell's law, FTIR, GT (general transmission) and so on. In addition, the experimental inspection for FTIR and moisture effects on the fingerprint image also evidenced the fact that the vivid fingerprint image originated from the moisture effect rather than the FTIR phenomenon.

Study on Pressure Fluctuations Observed in Combustion of Oxygen-Rich Preburners (산화제 과잉 예연소기 연소에서 관찰되는 압력섭동에 대한 연구)

  • Seo, Seonghyeon;Kang, Sang Hun;Lee, Soo-Yong
    • Journal of the Korean Society of Propulsion Engineers
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    • v.17 no.2
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    • pp.122-127
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    • 2013
  • The paper includes the analytic results of pressure fluctuation data from the combustion of an oxidizer-rich preburner applicable to high-performance, closed-cycle liquid rocket engine systems. The combustion experiments went through two different steps of a chamber pressure during single run. Self-excited pressure fluctuations with a frequency of 78 Hz were observed only at the relatively low chamber pressure condition. These pressure fluctuations are regarded as a bulk mode. The intensity of pressure fluctuations by a root-mean-square value is 13.3% normalized by the chamber static pressure and no pressure excitation was observed at the design pressure condition. The bulk mode has an identical phase across the inside of the chamber and reveals the similar characteristics to the Helmholtz resonator.

A Case study of engineering comprehensive design subject incorporating convergence with art (예술과의 융합을 접목한 공학 종합설계 교과목 사례연구)

  • Huh, Wonwhoi
    • Journal of the Korea Convergence Society
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    • v.13 no.4
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    • pp.195-201
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    • 2022
  • The core of the Fourth Industrial revolution, the topic of the 21st century, lies in the convergence of various technologies that are developing to the cutting edge. Therefore, convergence education is essential to solve problems from various perspectives. Above all, in order to solve the complex problem arising from the contact point between humans and technology in the future society, it was considered that insight through a humanities and artistic approach was necessary. Now, universities are trying to run a multidisciplinary comprehensive design to adapt to the new digital environment. In this study, an operation case of an engineering comprehensive design subject incorporating art operated by a researcher was described. The researcher presented an art convergence curriculum in a comprehensive design subject by applying 1. problem recognition and definition, 2. idea derivation and evaluation, 3. project development, 4. presentation, and demonstration process operation methods. Through this study, it is meaningful that it presented a method of operating art convergence in engineering comprehensive design subjects by allowing students to attempt an artistic aesthetic and emotional approach to project development.

The Defect Characterization of Luminescence Thin Film by the Positron Annihilation Spectroscopy (양전자 소멸 측정을 이용한 발광 박막 구조 결함 특성)

  • Lee, Kwon Hee;Bae, Suk Hwan;Lee, Chong Yong
    • Journal of the Korean Vacuum Society
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    • v.22 no.5
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    • pp.250-256
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    • 2013
  • It is described that the proton beam induces micro-size defects and electronic deep levels in luminescence Thin Film. Coincidence Doppler Broadening Positron Annihilation Spectroscopy (CDBPAS) and Positron lifetime Spectroscopy were applied to study of characteristics of a poly crystal samples. In this investigation the numerical analysis of the Doppler spectra was employed to the determination of the shape parameter, S-parameter value. The samples were exposed by 3.0 MeV proton beams with the intensities ranging between 0 to ${\sim}10^{14}$ particles. The S-parameter values decreased as increased the proton beam, that indicates the protons trapped in vacancies. Lifetime ${\tau}_1$ shows that positrons are trapped in mono vacancies. Lifetime ${\tau}_2$ is not changed according to proton irradiation that indicate the cluster vacancies of the grain structure.

The Removal of Humic Acid and Heavy Metals Using UV/TiO2/H2O2 (UV/TiO2/H2O2 공정을 이용한 휴믹산과 중금속 제거)

  • Kim, Jongoh;Jung, Jongtae;Choi, Wonyoul
    • Journal of the Korean GEO-environmental Society
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    • v.7 no.4
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    • pp.5-13
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    • 2006
  • This study was conducted to evaluate the application of $UV/TiO_2/H_2O_2$ process for treating humic acid and heavy metals in surface water. Removal efficiency of $UV/TiO_2/H_2O_2$ process was much more efficient than that of $UV/TiO_2$ process for humic acid and heavy metals removal. The removal rate of humic acid and heavy metals increased with the increase of $TiO_2$ dosage and UV intensity, however decreased with more than 0.3 g/L of $TiO_2$ dosage. The addition of $H_2O_2$ as an oxidant was a positive effect for the removal rate of humic acid and heavy metals especially in the concentration of 50 mg/L $H_2O_2$.

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Evaluation of Xerostomia Following Intensity Modulated Radiotherapy (IMRT) for Head and Neck Cancer Patients (세기조절방사선치료를 시행받은 두경부암 환자군에서 구강건조증지표 분석)

  • Lee, Seok-Ho;Kim, Tae-Hyun;Chie, Eui-Kyu;Im, Hyun-Shun;Im, En-Shil;Ryu, Jun-Sun;Jung, Yoo-Seok;Park, Sung-Yong;Kim, Joo-Young;Pyo, Hong-Ryull;Shin, Kyung-Hwan;Kim, Dae-Yong;Cho, Kwan-Ho
    • Radiation Oncology Journal
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    • v.22 no.2
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    • pp.106-114
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    • 2004
  • Purpose : This study was done to evaluate xerostomia fellowing intensity modulated radiotherapy for patients with head and neck cancer, and to analyze the correlation between the dosimetric parameters and xerostomia parameters. Materials and Methods : From February till October 2003, 13 patients with 3 months of follow-up were evaluated for xerostomia after being treated for head and neck cancer with IMRT. Their median age was 57 years(range: 43$\~$77). Xerostomia were assessed with a 4-question xerostomia questionnaire score (XQS) and a test for salivary flow rates (unstimulated and stimulated). The patients were also given a validated LENT SOMA scale (LSC) questionnaire. The evaluations were completed before radiation therapy (pre-RT) and at 1 and, 3 months after radiation therapy (RT). We evaluated xerostomia at pre-RT, 1 and, 3 months after RT. The association between the xerostomia parameters (XQS and LSC) and salivary flow rates (unstimulated and stimulated: USFR and SSFR) was assessed at 1 and 3 months after RT. Resrlts : All 13 patients showed no significant changes in XQS, LSC and Salivary Flow rates. As a result, we couldn't find out about xerostomia development. Based on the total mean parotid dose, 3,500 cGy, we divided these patients into two groups. The 8 patients (<3,500 cGy) showed no significant changes in XQS, LSC and Salivary Flow rates However, in 5 Patients ($\geq$3,500 cOGy), there was a significant increase in USFR and, SSFR at 3 months after RT, and for the XQS and, LSC at 1 and 3 months after RT. The correlation between XQS and, LSC, and USFR and, SSFR in ail patients (13) was significant at 3 months after RT. The correlation had a tendency to the decrease for USFR and, SSFR in proportion to the increase of XQS and, LSC. Conclusion : Based on the results of this study, IMRT seem to be an effective treatment to significantly decrease the xerostomia. XQS and, LSC seem to be a effective tool for predicting the xerostomia. A total parotid gland mean dose of <3,500 cGy should be a planning goal if substantial sparing of the gland function is desired. Furthermore, patients should be enrolled in a study to define a more accurate threshold dose for the parotid gland.

Characterizations of lithium niobate single crystals grown from melt with $K_2O$ ($K_2O$를 첨가한 융액으로부터 성장시킨 Lithium Niobate 단결정의 특성)

  • 김상수
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.8 no.4
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    • pp.525-531
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    • 1998
  • A series of $LiNbO_3$ single crystals were grown by the Czochralski method from a congruent melt, a congruent melt with 0.05 mol% $Fe_2O_3$, a congruent melt with 6 wt.% $K_2O$ and a congruent melt with 6 wt.% $K_2O$ and 0.05 mol% $Fe_2O_3$ respectively. The growth of $LiNbO_3$ crystal from a congruent melt 6 wt.% $K_2O$ leads to nearly stoichiometric specimens. This is established by studying the following properties; XRD patterns, temperature dependences of the phase transition temperature, energy of the fundamental absorption edge, the shape of the absorption band of the $OH^-$vibration and linewidths of the ESR of $Fe_{Li}^{3+}$.

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