• Title/Summary/Keyword: SSC

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Fabrication and analysis of $1.3\mum$ spot-size-converter integrated laser diodes (광모드변환기가 집적된 $1.3\mum$ SC-FP-LD 제작 및 특성 해석)

  • 심종인
    • Korean Journal of Optics and Photonics
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    • v.11 no.4
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    • pp.271-278
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    • 2000
  • We have fabricated and analyzed the lasing characteristics of 1.3$\mu\textrm{m}$ Spot-Size-Converter (SSC) integrated Fabry-Perot (FP) laser diodes, which are very promising light sources for optical subscriber networks. SSC-LDs has been developed by BIB (buttjoint-built-in) coupling and selective MOVPE growth. High-performances were achieved such as the slope efficiency from the SSC facet of 0.23-0.32 mW/mA, the full-width at the half maximum of the far-field pattern (FFP) of 9.5$^{\circ}$~12.3$^{\circ}$, the alignment tolerances of $\pm$2.3$\mu\textrm{m}$ and $\pm$2.5$\mu\textrm{m}$ within the extra-coupling loss of 1 dB for the vertical and parallel directions, respectively. These experimental results were compared to theoretical ones in order to clarify the operational problems and give a good design direction of the fabricated SSC-LDs. It was revealed that an asymmetric output power from the facets, an irrelevancy of FFP and the waveguide structure around SSC facet region, and a poor temperature characteristics were originated from the scattering in the BIB and SSC sections and SHB effect in the active section for the first time.t time.

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The Effect of SSC(Small-Scale Chemistry) Lab Program on Scientifically Gifted Students' Scientific Attitude, Creative Personality Characteristics and Science Inquiry Skills (SSC(Small-Scale Chemistry)실험이 과학영재의 과학적 태도, 창의적 성격 특성 및 과학탐구 능력에 미치는 효과)

  • Yoo, Mi-Hyun
    • Journal of Gifted/Talented Education
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    • v.20 no.2
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    • pp.487-502
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    • 2010
  • The purpose of this study was to examine the effect of SSC(Small-Scale Chemistry) lab program applying to scientifically gifted students' classes. The participants were 15 the middle school scientifically gifted students selected and enrolled in science-gifted education center of university. SSC lab program was applied for 3 month with 5 topics. The research design was one group pretest-posttest design, the data were analyzed using the PASW 18 statistics program. The results of this study were as follows: First, the scientific attitude of scientifically gifted students was improved significantly(p<.01) after applying SSC lab program. Especially, there were significant difference between pre-test and post-test in the scores of cooperativity, spontaneity, perseverance, which were the sub-region of scientific attitude. Second, the creative personality characteristics of scientifically gifted students showed statistically significant improvements(p<.01) after applying SSC lab program. Especially, there was significant difference between pre-test and post-test in the scores of adhesion, which was a sub-region of the creative personality characteristics. Third, there were no significant differences in the science inquiry skills between before and after applying the SSC lab program in the scientifically gifted students' classes(p>.05). The results suggest that SSC Lab program is an effective program in scientifically gifted students' classes.

Development of a System Analysis Code, SSC-K, for Inherent Safety Evaluation of The Korea Advanced Liquid Metal Reactor

  • Kwon, Young-Min;Lee, Yong-Bum;Chang, Won-Pyo;Dohee Hahn;Kim, Kyung-Doo
    • Nuclear Engineering and Technology
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    • v.33 no.2
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    • pp.209-224
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    • 2001
  • The SSC-K system analysis code is under development at the Korea Atomic Energy Research Institute (KAERI) as a part of the KALIMER project. The SSC-K code is being used as the principal tool for analyzing a variety of off-normal conditions or accidents of the preliminary KALIMER design. The SSC-K code features a multiple-channel core representation coupled with a point kinetics model with reactivity feedback. It provides a detailed, one-dimensional thermal-hydraulic simulation of the primary and secondary sodium coolant circuits, as well as the balance-of-plant steam/water circuit. Recently a two-dimensional hot pool model was incorporated into SSC-K for analysis of thermal stratification phenomena in the hot pool. In addition, SSC-K contains detailed models for the passive decay heat removal system and a generalized plant control system. The SSC-K code has also been applied to the computational engine for an interactive simulation of the KALIMER plant. This paper presents an overview of the recent activities concerned with SSC-K code model development This paper focuses on both descriptions of the newly adopted thermal hydraulic and neutronic models, and applications to KALIMER analyses for typical anticipated transients without scram.

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Study on EEC and SSC of the Electric Resistance Welded Linepipe Steel

  • Kim, Wan Keun;Koh, Seong Ung;Yang, Boo Young;Kim, Kyoo Young
    • Corrosion Science and Technology
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    • v.6 no.3
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    • pp.96-102
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    • 2007
  • The resistance of the linepipe steel to hydrogen-induced cracking (HIC) and sulfide stress cracking (SSC) is very important for steel to be used in sour oil/gas environments. Welding of steels is necessary to the construction of pipe-line transporting oil/gas. In this study, HIC and SSC resistance of an electric resistance welded (ERW) steel plate which belongs to API X70 grade was evaluated by using NACE TM0284-96A and NACE TM0177-96A methods. HIC and SSC fracturing behavior was investigated by observing fractured surfaces using optical microscopy (OM) and scanning electron microscopy (SEM). It was discussed in terms of metallurgical parameters such as the distribution of primary microstructure, second phases and inclusions. Results showed that the weld joint of ERW steel is more sensitive than base metal to HIC and SSC. This is due to difference in the contribution of metallurgical parameters to HIC and SSC nucleation and propagation.

Learning Effects According to the Level of Science State Curiosity and Science State Anxiety Evoked in Science Learning (과학 학습에서 유발되는 과학상태호기심 및 과학상태불안 수준에 따른 학습효과)

  • Kang, Jihoon;Kim, Jina
    • Journal of The Korean Association For Science Education
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    • v.41 no.3
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    • pp.221-235
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    • 2021
  • The purpose of this study is to investigate the learning effects according to the level of Science State Curiosity (SSC) and Science State Anxiety (SSA) in science learning situation for 5th~6th grade elementary school students. To achieve this purpose, we measured and analyzed SSC and SSA in each learning situation by dividing science learning into three situations: Confronting scientific task (I), Checking the results (II), and Learning science concepts (III). In order to identify the net effects of SSC and SSA on learning effects, science curiosity, need for cognition, science self-concept, science anxiety, and interest, which were expected to affect the learning effects, were controlled. SSC and SSA in the situation of confronting scientific tasks were defined as 'SSCI' and 'SSAI,' SSC and SSA in the situation of checking the results were defined as 'SSCII' and 'SSAII,' and SSC and SSA in the situation of learning science concepts were defined as 'SSCIII' and 'SSAIII.' In addition, the learning effects were divided into post-learning effect and delayed post-learning effect, and the degree of improvements in the post- or delayed post-test scores compared to the pre-test score were calculated and analyzed. As a result of the analysis, SSCI·SSCII had a positive effect on the post- and the delayed post-learning effect, but SSAIII had a negative effect on the post- and delayed post-learning effect, SSAI·SSAII had a negative effect on the post-learning effect. SSC had a greater effect on learning effects than SSA, and SSCII had the most influence on the post-learning effect and SSCI had the most influence on the delayed post-learning effect. As SSCIII increased, there was a tendency to do additional voluntary learning. The results of this study are expected to broaden the understanding of students' emotional states in science learning and provide a theoretical foundation for studies of state curiosity and state anxiety.

Novel Sesquiterpenoid Compounds from Culture Broth of Stereum hirsutum

  • Cho, Yang-Rae;Yun, Bong-Sik;Lee, In-Kyoung;Lee, Tae-Ho;Yoo, Ick-Dong
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1998.11a
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    • pp.130-130
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    • 1998
  • Two novel compounds SSC1 and SSC2 were isolated from culture broth produced from the strain of Stereum hirsutum by using of YM broth. They were isolated through HP-20 column chromatography, silica gel column chromatography and preparative HPLC, successively. The molecular formulas of SSC1 and SSC2. were determined as C$\sub$15/H$\sub$22/O$_3$ by high resolution EI -mass. The chemical structures of SSC1 and SSC2 were determined as sesquiterpenoid compounds by spectroscopic analysis of UV, IR, $^1$H NMR, $\^$13/C NMR, DEPT, HMQC and HMBC spectrum.

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Performance Analysis of NOMA with Symmetric Superposition Coding

  • Chung, Kyuhyuk
    • Journal of IKEEE
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    • v.23 no.1
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    • pp.314-317
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    • 2019
  • Recently, the symmetric superposition coding (SSC) [3] is proposed for a solution for the error propagation (EP) due to the non-perfect successive interference cancelation (SIC) in non-orthogonal multiple access (NOMA). We analyze the performance of NOMA with the SSC. It is shown that the performance of the SSC NOMA is the same as that of NOMA with the normal superposition coding (NSC) for the power allocation factor less than 20%, the SSC NOMA performance is better than the NSC NOMA performance up to the power allocation factor 80%, and the SSC NOMA performs worse than the NSC NOMA for the power allocation factor greater than 80%. As a result, the SSC should be used with consideration of the power allocation.

Expression of HBP2 in Human Spermatogonial Stem Cell-like Cells from Nonobstructive Azoospermia Patients and Its Role in G1/S Transition & Downregulation in Colon Cancer

  • Yoo, Jung-Ki;Lee, Dong-Ryul;Lim, Jung-Jin;Kim, Jin-Kyeoung
    • Reproductive and Developmental Biology
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    • v.32 no.4
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    • pp.211-215
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    • 2008
  • The HMG box containing protein (HBP) has a high mobility group domain and involved in the regulation of proliferation and differentiation of tissues. We screened HBP2 in glioblastoma using Suppression Subtractive Hybridization (SSH) and isolated human spermatogonial stem cell-like cells (hSSC-like cells) derived from patients of nonobstructive azoospermia (NOA). Expression of HBP2 was analyzed by RT-PCR in undifferentiated stem cells (human Embryonic Stem Cells, hSSC-like cells 2P) and spontaneous differentiated stem cells (hSSC-like cells 4P). It was overexpressed in hESC and hSSC-like cells 2P but not in hSSC-like cells 4P. Also, the expression level of HBP2 was downregulated in colon tumor tissues compared to normal tissues. Specifically in synchronized WI-38 cells, HBP2 was highly upregulated until the G1 phase of the cell cycle and gradually decreased during the S phase. Our results suggest that HBP2 was downregulated during the spontaneous differentiation of hSSC-like cells. HBP2 was differently expressed in colon tissues and was related to G1-progression in WI-38 cells. It may playa role in the maintenance of an undifferentiated hSSC-like cell state and transits from G1 to S in WI-38 cells. This research was important that it identified a biomarker for an undifferentiated state of hSSC-like cells and characterized its involvement to arrest during cell cycle in colon cancer.

The Effects of Experimental Learning Using the Small-Scale Chemistry on High School Students' Academic Achievement, Scientific Attitude and Science-related Attitude in Chemistry I (Small-Scale Chemistry를 활용한 실험수업이 고등학생들의 화학 I 교과 학업성취도와 과학적 태도 및 과학에 관련된 태도에 미치는 영향)

  • Kim, Ji-Sook;Hwang, Hyun-Sook;Park, Se-Yeol;Kim, Dong-Jin;Park, Kuk-Tae
    • Journal of Science Education
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    • v.35 no.2
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    • pp.119-126
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    • 2011
  • The purpose of this study was to examine the effects of experimental learning using the small-scale chemistry (SSC) on high school students' academic achievement, scientific attitude and science-related attitude in high school chemistry I. For this study, two high school 2nd grade classes were divided into an experimental group and a control group. Experimental learning using the SSC in the experimental group, traditional experimental learning presented in the textbook in the control group were performed. The results showed that experimental learning using the SSC compared to traditional experimental learning was effective in improving academic achievement. The experimental learning also was effective in improving voluntary, patience, cooperativity in the scientific attitudes and social implications of science, attitude for science curriculum, attitude toward science in the science-related attitudes. Therefore, experimental learning using the SSC is necessary to actively utilize in high school chemistry curriculum.

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Compression Behavior of Steel Plate-Concrete Structures for both Stiffened and Nonstiffened structures by Rib (리브 보강 유무에 따른 강판-콘크리트 구조의 압축거동)

  • Choi, Byong Jeong;Han, Hong Soo;Han, Kweon Gyu;Lee, Seung Joon
    • Journal of Korean Society of Steel Construction
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    • v.21 no.5
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    • pp.471-481
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    • 2009
  • The purpose of this study was to compare and analyze the compression behaviors of SSC (stiffened steel plate-concrete) and NSC (non-stiffened steel plate-concrete) structures, and to identify the effects of the increment in the structural performance of SSC structures. SCC structures are structures that integrate steel plates with line support from ribs (H-shape) and point supports from studs with concretes. On the other hand, NSC structures are structures that integrate steel plates with point supports from studs with concrete. The following results were obtained in this study. First, compared with NSC structures, it was shown that SSC structures have advantages in terms of preventing steel plate buckling and delaying quick destruction through the brittleness of concrete. In addition, the SSC structures showed a 5-28% increment in maximum compressive strength, which far surpassed that shown by the NSC structures.