• Title/Summary/Keyword: 권상부하

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Wafer Level Hermetic Sealing Characteristics of RF-MEMS Devices using Non-Conductive Epoxy (비전도성 에폭시를 사용한 RF-MEMS 소자의 웨이퍼 레벨 밀봉 실장 특성)

  • 박윤권;이덕중;박흥우;송인상;김정우;송기무;이윤희;김철주;주병권
    • Journal of the Microelectronics and Packaging Society
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    • v.8 no.4
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    • pp.11-15
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    • 2001
  • In this paper, hermetic sealing technology was studied for wafer level packaging of the RF-MEMS devices. With the flip-chip bonding method. this non-conductive B-stage epoxy sealing will be profit to the MEMS device sealing. It will be particularly profit to the RF-MEMS device sealing. B-stage epoxy can be cured by 2-step and hermetic sealing can be obtained. After defining 500 $\mu\textrm{m}$-width seal-lines on the glass cap substrate by screen printing, it was pre-baked at $90^{\circ}C$ for about 30 minutes. It was, then, aligned and bonded with device substrate followed by post-baked at $175^{\circ}C$ for about 30 minutes. By using this 2-step baking characteristic, the width and the height of the seal-line could be maintained during the sealing process. The height of the seal-line was controlled within $\pm$0.6 $\mu\textrm{m}$ in the 4 inches wafer and the bonding strength was measured to about 20MPa by pull test. The leak rate, that is sealing characteristic of the B-stage epoxy, was about $10^{-7}$ cc/sec from the leak test.

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A Study on the Process of Pacific Park Development in NYC -Focusing on the Changes & Responds Shown in the Development Process- (뉴욕시 퍼시픽 파크 개발의 진행과정에 대한 분석적 고찰 -개발 진행상의 변화 및 위기대응과정을 중심으로-)

  • Lee, Woo Hyoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.745-752
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    • 2020
  • The purpose of this study is to analyze the development progress of Pacific Park (formerly Atlantic Yard) in Brooklyn, New York City. Along with the Hudson Yards Development in Manhattan, Pacific Park is one of New York City's leading large-scale urban development projects using space right above an existing railway and has attracted worldwide attention. With the resurgence of large-scale development, its advanced form has received social attention. In particular, the development was evaluated as an exemplary development using the Community Benefits Agreement, which benefits local residents. Unfortunately, due to various difficulties, the development has been struggling from delays and changes away from the early stages, which have also caused social concerns and criticism. In this regard, this study examines the development through the process and the public sector's responses to the risk-inducing factors and reactions. The theoretical background of the US urban redevelopment is examined, and the specific changes and major contents of the project are analyzed. The following implications were drawn based on changes and responses in the development process: 1) securing the flexibility and mandatoryness of developers, 2) comprehensive control of the development site, 3) communication with and responding to the public, 4) securing additional financial resources, and 5) verification of new technologies.

Pharmacokinetics and the Intestinal Permeability of Amaranth in Rats (적색식용색소인 아마란스의 약동학 특성 및 위장관 투과도 연구)

  • Han, Youjin;Goo, Soo Hyeon;Nam, So Jeong;Kang, Yun Ju;Kwon, Mihwa;Song, Im-Sook
    • Journal of Life Science
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    • v.27 no.7
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    • pp.812-816
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    • 2017
  • Although amaranth, a red-colored tar dye, is usually used in foods, cosmetics, and pharmaceutics, its bioavailability and intestinal absorption have not previously been investigated. Therefore, the purpose of this study was to investigate the pharmacokinetics properties and intestinal permeability of amaranth in rats following the intravenous and oral administration of this dye. Amaranth rapidly disappeared from the plasma following the intravenous injection, with a half-life of 38.8 minutes. However, the plasma concentration of amaranth was increased to 400 minutes following the oral administration of amaranth, and the absorption time and bioavailability of amaranth were calculated to be 356 minutes and 55.6%, respectively. This suggests that once amaranth exists in the gut, this dye may be efficiently and effectively absorbed. Consistent with this result, the intestinal permeability of amaranth was comparable to atenolol, a marker compound of moderate permeability, and to one-third of caffeine's intestinal permeability (a highly permeable compound). In conclusion, a significantly long absorption time and substantial intestinal absorption of amaranth was observed following the oral administration of amaranth at a dose of 300 mg/kg in rats, despite the rapid elimination of this dye from the plasma. These results may suggest the necessity of a careful and limited use of amaranth dye when it is added to food, lip-care cosmetics, and orally administered pharmaceutics.

서안경계류 발생역학을 이해하기 위한 실험 장치 및 방법 개발

  • Jang, Seung-Hwan;Sin, Jeong-Seon;Mun, Byeong-Gwon
    • 한국지구과학회:학술대회논문집
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    • 2010.04a
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    • pp.48-50
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    • 2010
  • Stommel(1948)은 서안경계류의 원인이 베타효과($\beta$-effect)라 일컫는 코리올리 파라미터(f)의 위도 변화 때문인 것을 밝혔다. 서안경계류는 고등학교나 대학 교양에서 중요하게 다뤄지고 있다. 학생들은 보통 이론 수업만으로 서안경계류의 발생 과정, 이에 관련된 코리올리 힘, 베타효과 등을 이해해야 한다. 때문에 서안경계류와 관련된 실험이 있다면 이를 이해하는 데 큰 도움이 될 것이다. 또한 연구에서 검토한 6종의 고등학교 지구과학 2 교과서는 서안경계류를 본문과 더불어 삽화로 설명하고 있다. 그러나 이 중 3종의 교과서 삽화에서는 서안경계류의 발생 원인을 코리올리 힘만으로 지적하고 있다. 따라서 일부 학생은 서안경계류의 원인을 코리올리 힘으로 오해 할 수 있다. 위와 같은 이유로 우리는 서안경계류가 코리올리 힘의 작용과 베타효과에 의해 나타나는 것을 쉽게 확인 할 수 있는 실험 장치와 다양한 실험 방법을 개발하였다. 개발한 실험 장치는 직육면체의 수조와 회전 속도를 조절할 수 있는 테이블로 구성된다. (Fig. 1) 이와 같은 회전수조는 대기와 해양의 움직임을 실험실에서 모사하기 위해 자주 사용되었다(Beardsely 1969, 소선섭 등 1995; 1997). 우리의 수조는 경사진 바닥과 평평한 바닥으로 두종류를 제작하였다. 바닥이 경사진 수조는 베타효과를 구현하기 위한 것이다. 반시계 방향으로 회전하는 테이블은 중위도 어떤 위도에 접하는 가상의 평면이 지구 자전에 의해 회전하는 것을 나타낸다. 그리고 수조 상부에는 회전원판을 물에 접하여 시계방향으로 회전시킨다. 회전원판은 북반구 중위도 해양에 작용하는 바람 응력을 나타낸다. 우리는 테이블의 회전유무와 바닥의 경사유무에 따라 4개 실험을 수행하였다(Table. 1). 각 실험에서 물을 채운 수조를 원판에 올려놓고, 회전원판을 작동시킨 후 20분 동안 그대로 두어 수조안의 미세규모의 운동을 최소화 시킨 후 잉크를 떨어뜨리고 관찰하였다. 그 결과 실험 SB_f1은 베타효과와 코리올리 힘이 존재하여 서쪽 경계에서 좁고 빠른 흐름을 만들고 수조의 중간 부근에서 경계를 벗어나 동쪽으로 향하고 있다. 이 모습은 실제 해양의 서안경계류의 분리 현상과 비슷하다. FB_f1은 코리올리 힘만 존재하여 서쪽 경계에서 좁고 빠른 순환과 경계를 벗어나 동쪽으로 분리되는 흐름이 나타나지 않으며 전반적으로 크게 회전하는 모습을 보인다. SB_f0은 바람의 응력만 존재하는 경우로 잉크가 확산하는 모습을 보이며 나선팔의 모양으로 회전하면서 넓게 퍼져나간다. FB_f0의 모양도 이와 비슷하게 나타난다. 실험 SB_f1과 FB_f1을 비교하여 서안경계류는 코리올리 힘의 위도변화 효과인 베타효과가 있을 때 발생한다는 것을 알 수 있다(Fig. 2). 이 결과는 "단순히 코리올리 효과에 의해 서안경계류가 발생한다"는 생각을 바꾸게 할 것이다. 덧붙여 서안경계류 분리와 수조 바닥의 경사의 관계를 살펴보기 위한 실험을 실시하였다. 경사가 더 급하면 ($\alpha=20^{\circ}$) 서쪽 경계를 벗어나는 지점이 좀 더 북쪽에 나타났다. 현재 서안경계류는 개발한 실험 장치와 방법을 학교 현장에 적용하여 그 교육적 활용 가치를 평가하는 연구를 진행하고 있다.

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Oviposition Preferences of the Oriental Chestnut Gall Wasp, Dryocosmus kuriphilus, on Various Chestnut Varieties (밤나무품종에 따른 밤나무혹벌의 산란 선호성)

  • Kim Chul-Su;Park Il-Kwon;Kim Jong-Kuk;Park Yeong-Suk;Shin Sang-Chul;Chung Yeong-Jin;Choi Kwang-Sik;Jeon Mun-Jang
    • Korean journal of applied entomology
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    • v.44 no.2
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    • pp.157-159
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    • 2005
  • The number of winter buds oviposited by Drycosmus kuriphilus against chestnut varieties was lower of Ishizuchi and Daap than that of Okkwang, Tsukuba and Arima. D. kuriphilus oviposited multiful eggs in each winter bud of most of the chestnut varieties tested. More than three eggs were oviposited on winter bud of lower shoot of native, Tsukuba, Okkwang and Pyounggi varieties. However, average laid eggs less than one were on winter buds of Tshizuchi and Daap. Number of eggs oviposited in winter bud on lower shoot was higher than those on upper one. More than 15 eggs were oviposited in Tsukuba, whereas one or less egg was oviposited in Daap. Rates of winter buds oviposited by D. kuriphilus in native, Arima and Tsukuba were 83.8, 78.5, and $75.9\%$, respectively.

Development of Cloud Chamber by Using Peltier Device (펠티에 소자를 이용한 안개상자 개발)

  • Woo, Jong-Kwan;Kwon, Jin-Young;Park, Sang-Tae
    • Journal of Radiation Protection and Research
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    • v.36 no.3
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    • pp.134-139
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    • 2011
  • In this research, we developed the newly cloud chamber apparatus by using Peltier device to apply nuclear physics experiment in high school or university. We observed the cosmic rays track by using the developed apparatus and a camcorder. And we compared and analyzed the acquired data. From the results, we acquired the following conclusions and suggestions : First, it is very difficult to observe the cosmic rays track in the typical cloud chamber because of the low frequency of it. But in the newly developed cloud chamber we can observe easily the cosmic rays track owing to the high frequency of it. Second, when we do the experiment with the newly developed apparatus, we found that the cosmic rays track happens well under the condition that the temperature of the upper place of cooling plate must be below 5$^{\circ}C$ with more than isopropanol $1.04{\times}10^{-5}$ $ml{\cdot}mm^{-3}$. Third, the newly developed apparatus will be improved to have better precision by controling the temperature of cooling plate in the cloud chamber by current intensity. Therefore we think that it is very useful to use the newly developed apparatus in the nuclear physics experiment in highschool or university.

Development of Hydro-Mechanical Coupling Method for CO2 Sequestration and Its Application to Sleipner Project (이산화탄소 지중저장을 위한 수리-역학 연동 해석 기술 개발 및 적용 - 슬라이프너 프로젝트)

  • Kwon, Sangki;Lee, Hyeji
    • Tunnel and Underground Space
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    • v.27 no.3
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    • pp.146-160
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    • 2017
  • $CO_2$ sequestration for alleviating global warming is a hot issue in the world. In this study, TOUGH2 and FLAC3D were combined for analyzing the hyro-mechanical coupling behaviors expected in $CO_2$ sequestration and applied it to Sleipner project carried out in Norway. In the analysis, the influence of pore pressure on in situ stress was considered and the influence of caprock permeability on hydro-mechanical behaviors was analyzed. In the condition of constant injection rate, pressure and saturation at the injection well, liquid and gas saturation in rock, major and minor stress variations with time and distance from the injection well, and horizontal and vertical displacements after injection could be investigated. The major principal stress was quickly increased in the early stage and then slowly decreased to a stable value, which was higher than the initial value. In contrast, the minor principal stress returned to initial value after some increase in the early stage. Surface upheaval was steadily increased and it was up to 15mm in 2 years after injection. When the caprock's permeability was changed from $3e-15m^2{\sim}3e-18m^2$, it was found that the injection well pressure and surface upheaval were inversely propotional to the permeability.

Development of a safe culture technique for Agrocybe cylindracea (버들송이버섯 봉지재배 안정생산 기술)

  • Heo, Byong-Soo;Seo, Sang-Young;Choi, Kyu-Hwan;Choi, Young-Min;Kwon, Seog-Ju;Jang, Kab-Yeyl;Yoo, Young-Jin
    • Journal of Mushroom
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    • v.17 no.1
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    • pp.1-6
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    • 2019
  • Agrocybe cylindracea was cultured in a bag, in which sawdust culture medium (1 kg) is put in a plastic bag (PE), with poplar sawdust, rice bran, wheat bran, and dried bean curd refuse in the ratio of 70:10:10:10 (v/v). 2% of the culture medium was inoculated with the liquid starter of Agrocybe cylindracea, and this was incubated at $25^{\circ}C$. After incubation, the A. cylindracea was further cultured by cutting the top vinyl portion of the bag down to the level of the culture medium surface of the first inoculation part. The cut culture medium was placed in a growth room at $25^{\circ}C$, and pin-heading was induced under light irradiation at 99% humidity and 1,000 ppm $CO_$ level for 3days. When the grow the environment was controlled at 95% humidity and $21^{\circ}C$, the bending of the stem was less as compared to that when the cap of the bag had been removed. The number of effective fruiting bodies per bag increased by 140% (28.8), the quantity per bag increased by 29.5%, and 148.5 g A. cylindracea could be potentially harvested.

Mediastinal Lymph Node Metastasis from Head and Neck Cancer: Predictive Factors and Imaging Features (두경부암의 종격동 림프절 전이: 예측인자 및 영상 소견)

  • Il Kwon Ko;Dae Young Yoon;Sora Baek;Ji Hyun Hong;Eun Joo Yun;In Jae Lee
    • Journal of the Korean Society of Radiology
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    • v.82 no.5
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    • pp.1246-1257
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    • 2021
  • Purpose To assess the predictive factors and describe the imaging features of mediastinal lymph node (MLN) metastases in patients with head and neck cancer. Materials and Methods We compared the clinical features and disease characteristics (sex, age, site of primary tumor, histologic type, history of prior treatments, TNM stages, and metastasis in cervical LNs) of patients with head and neck cancers between the MLN metastasis and no MLN metastasis groups. We also evaluated the chest CT (distribution and maximum dimension of the largest LN) and PET/CT (maximum standardized uptake value) features of MLN metastases based on the MLN classification. Results Of the 470 patients with head and neck cancer, 55 (11.7%) had MLN metastasis, involving 150 mediastinal stations. Hypopharynx cancer, recurrent tumor, T4 stage, N2/N3 stages, and M1 stage were found to be significant predicting factors for MLN metastasis. The most common location of MLN metastasis was ipsilateral station 2 (upper paratracheal LNs, 36.4%), followed by ipsilateral station 11 (interlobar LNs, 27.3%) and ipsilateral station 10 (hilar LNs, 25.5%). Conclusion Metastasis to MLNs should be considered in patients with head and neck cancer, especially in cases that are associated with a hypopharyngeal cancer, recurrent tumor, and high TNM stages.

Clinical Experience on Mycobacterial Diseases Other Than tuberculosis (비결핵마이코 박테리엄증의 임상 경험)

  • Lew, W.J.;Ahn, D.I.;Yoon, Y.J.;Cho, J.S.;Kwon, D.W.;Kim, S.J.;Hong, Y.P.
    • Tuberculosis and Respiratory Diseases
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    • v.39 no.5
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    • pp.425-432
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    • 1992
  • Background: The prevalence of tuberculosis in Korea decreased remarkably for the past 30 years, while for at least the recent 10 years, the frequency of disease attributable to mycobacteria other than tuberculosis (MOTT) began to increase both in actual numbers and in the proportion of the total burden of mycobacterioses. Method: Twenty nine cases, diagnosed as having pulmonary disease due to MOTT on the basis of repeated isolations of the relevant organisms from sputum specimens and chest X-ray findings from Jan. 1982 throught Dec. 1991 at the Chest Clinic of the Korean Institute of Tuberculosis, were reviewed in terms of clinical features and courses. Results: 1) Nineteen cases (66%) were infected with Mycobacterium avium-intracellulare, 5 cases (17%) with M. fortuitum, 4 cases (14%) with M. chelonei, and 1 cases (3%) with M. szulgai. 2) The ratio of male versus female patients was 1.9:1. 3) The peak incidence was in the fifth decade. 4) Eighteen cases (62%) had moderately advanced disease and 11 cases (38%) had far advanced disease on chest P-A film. 5) The common symptoms were cough (59%), sputum (52%), and dyspnea (34%). 6) All cases had a previous history of tuberculosis. 7) Most of the isolates were highly resistant to the major antituberculosis drugs and 48~52% showed a sensitivity to cycloserine, kanamycin or enviomycin. 8) Of 19 cases which were treated and followed-up for over 12 months, 3 cases attained negative conversion on cultures (2 M. fortuitum infections, 1 M. szulgai infection). Sixteen cases failed in attaining negative conversion on cultures. However, their clinical courses were chronic and indolent despite of persistant culture positivity. Conclusion: Treatment of these patients has been difficult because of the frequency of severe underlying conditions and the natural resistance of most of the nontuberculous mycobacteria to the presently available drugs.

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