• 한국수학교육학회지시리즈E:수학교육논문집
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• 제18권2호
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• pp.9-33
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• 2004

The purpose of this paper is to contribute to the dialogue about the notion of advanced mathematical thinking by offering an alternative characterization for this idea, namely advancing mathematical activity. We use the term advancing (versus advanced) because we emphasize the progression and evolution of students' reasoning in relation to their previous activity. We also use the term activity, rather than thinking. This shift in language reflects our characterization of progression in mathematical thinking as acts of participation in a variety of different socially or culturally situated mathematical practices. We emphasize for these practices the changing nature of student' mathematical activity and frame the process of progression in terms of multiple layers of horizontal and vertical mathematizing.

• Nuclear Engineering and Technology
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• 제41권1호
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• pp.63-70
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• 2009

A steam generator tube rupture (SGTR) accident, which is a partial reactor building bypass scenario, has a low probability and high consequences. SAMG has been used to manage the progression of severe accidents and the release of fission products induced by an SGTR at the Wolsong plants. Four of the six SAGs in the SAMG are used to manage the progression of a severe accident induced by an SGTR at the Wolsong plants. The results of the ISAAC code calculation have shown that the proper use the SAMG can stop a severe accident from progressing and keep the reactor building intact during a severe accident. These results confirm that the SAMG is an effective means of managing the progression of severe accidents initiated by an SGTR at the Wolsong plants.

• BMB Reports
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• 제46권3호
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• pp.131-138
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• 2013

During cancer progression, bone marrow derived myeloid cells, including immature myeloid cells and macrophages, progressively accumulate at the primary tumour site where they contribute to the establishment of a tumour promoting microenvironment. A marked infiltration of macrophages into the stromal compartment and the generation of a desmoplastic stromal reaction is a particular characteristic of pancreatic ductal adenocarcinoma (PDA) and is thought to play a key role in disease progression and its response to therapy. Tumour associated macrophages (TAMs) foster PDA tumour progression by promoting angiogenesis, metastasis, and by suppressing an anti-tumourigenic immune response. Recent work also suggests that TAMs contribute to resistance to chemotherapy and to the emergence of cancer stem-like cells. Here we will review the current understanding of the biology and the pro-tumourigenic functions of TAMs in cancer and specifically in PDA, and highlight potential therapeutic strategies to target TAMs and to improve current therapies for pancreatic cancer.

• Nuclear Engineering and Technology
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• 제49권6호
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• pp.1326-1338
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• 2017

The continuous energy Monte Carlo neutron transport code, MC21, was coupled to the CTF subchannel thermal-hydraulics code using a combination of Consortium for Advanced Simulation of Light Water Reactors (CASL) tools and in-house Python scripts. An MC21/CTF solution for VERA Core Physics Benchmark Progression Problem 6 demonstrated good agreement with MC21/COBRA-IE and VERA solutions. The MC21/CTF solution for VERA Core Physics Benchmark Progression Problem 7, Watts Bar Unit 1 at beginning of cycle hot full power equilibrium xenon conditions, is the first published coupled Monte Carlo neutronics/subchannel T-H solution for this problem. MC21/CTF predicted a critical boron concentration of 854.5 ppm, yielding a critical eigenvalue of $0.99994{\pm}6.8E-6$ (95% confidence interval). Excellent agreement with a VERA solution of Problem 7 was also demonstrated for integral and local power and temperature parameters.

• ETRI Journal
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• 제43권4호
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• pp.650-659
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• 2021

Multi-carrier waveforms have several advantages over single-carrier waveforms for radar communication. Employing multi-carrier complementary phase-coded (MCPC) waveforms in radar applications has recently attracted significant attention. MCPC radar signals take advantage of orthogonal frequency division multiplexing properties, and several authors have explored the use of MCPC signals and the difficulties associated with their implementation. The sidelobe level and peak-to-mean-envelope-power ratio (PMEPR) are the key issues that must be addressed to improve the performance of radar signals. We propose a scheme that applies pattern-based scaling and geometric progression methods to enhance sidelobe and PMEPR levels in MCPC radar signals. Numerical results demonstrate the improvement of sidelobe and PMEPR levels in the proposed scheme. Additionally, autocorrelations are obtained and analyzed by applying the proposed scheme in extensive simulation experiments.

• Genomics & Informatics
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• 제21권1호
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• pp.11.1-11.5
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• 2023

Breast cancer is the most common cancer worldwide, and advanced breast cancer with metastases is incurable mainly with currently available therapies. Therefore, it is essential to understand molecular characteristics during the progression of breast carcinogenesis. Here, we report a dataset of whole genomes from the human mammary epithelial cell system derived from a reduction mammoplasty specimen. This system comprises pre-stasis 184D cells, considered normal, and seven cell lines along cancer progression series that are immortalized or additionally acquired anchorage-independent growth. Our analysis of the whole-genome sequencing (WGS) data indicates that those seven cancer progression series cells have somatic mutations whose number ranges from 8,393 to 39,564 (with an average of 30,591) compared to 184D cells. These WGS data and our mutation analysis will provide helpful information to identify driver mutations and elucidate molecular mechanisms for breast carcinogenesis.

• 과학교육연구지
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• 제41권3호
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• pp.382-404
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• 2017

이 연구에서는 2015년 국가수준 학업성취도 평가(NAEA)의 서답형 문항을 이용하여 중학교 과학 교과의 8개 핵심 개념에 대한 학습발달과정을 탐색하고자 하였다. 이를 위해 2015년 실시된 NAEA 서답형 8개 문항에 대한 중학교 3학년 7,390명의 응답 결과를 전산으로 입력하고 입력된 답안을 분석하여 수준별로 유형화하는 과정을 거쳤다. 이 과정을 마친 후 각 평가 구인별로 5개 수준을 설정하여 구인구성도를 작성하였다. 이 연구에서의 구인구성도는 발달 기반의 루브릭 형식으로 작성되었는데, 전체 학생들의 답안에 대해 수준을 부여하는 준거로 활용되었다. 또한, 평가 결과로 얻은 학생들의 점수를 평가 구인에 대한 성취 수준과 연결하기 위하여 통계적 해석으로 응답자의 점수나 성취 정도를 측정하는 Rasch 모델을 적용하였다. 마지막으로, Rasch 모델 적용 결과를 반영하여 구인구성도를 수정한 예비 학습발달과정을 작성하였다. 이 연구는 NAEA의 서답형 문항을 활용하여 학습발달과정 개발 가능성을 탐색하였다는 데 의의가 있다. 하지만, 이 연구에서 작성된 예비 학습발달과정이 개별 학생들 대상으로 종적으로 추적한 것이 아니므로 여전히 가설적이며 추론적이다. 그러므로 반복적인 연구 과정을 통해 지속적으로 수정 및 보완될 필요가 있다.

• 한국안광학회지
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• 제17권1호
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• pp.19-26
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• 2012

목적: 최근 근시진행 억제를 위한 방법으로 대두되고 있는 Myopia Control 렌즈를 단초점렌즈 착용자와 비교하여 임상적인 근시조절 효과를 연구하고자 한다. 방법: 대구 경북 지역의 8~15세 근시안 56명(112안)을 대상으로 굴절이상도, 안축장, 폭주 근점, 조절 근점을 기준시점, 1개월, 6개월 후 총 3회 측정하여 비교하였다. 결과: 굴절이상도는 SV렌즈보다 MC렌즈를 착용하였을 때 등가 구면굴절력의 진행이 억제 및 완화되었으며, 안축장도 MC렌즈를 착용하였을 때 안축장 진행이 유의하게 억제 및 지연되었다(p<0.05). 폭주 근점은 SV렌즈보다 MC렌즈를 착용하였을 때 가까워졌고 폭주력이 개선되었으며, 조절 근점은 MC렌즈를 착용하였을 때 가까워졌으며, 조절력이 유의하게 개선되었다(p<0.05). 결론: 학령기 아동 청소년의 근시진행에 있어서 SV렌즈에 비해 MC렌즈가 근시의 진행을 완화시킬 수 있음을 보여주었다. MC렌즈는 증가하고 있는 많은 근시안 아동 청소년의 근시진행 억제에 유용한 치료법으로 활용될 수 있을 것으로 사료된다.

• 한국지구과학회지
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• 제38권3호
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• pp.222-238
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• 2017

이 연구의 목적은 지구과학 탐구에서 통합 탐구 기능에 대한 학생들의 학습발달과정을 탐색하는 것이다. 이를 위해 과학 탐구 기능 발달과정 관련 문헌의 조사를 통해 '탐구 설계', '자료 수집', '자료 해석', 그리고 '결론 도출'을 발달 변인으로 설정하고, 각각에 대한 가설적 학습발달과정(HLP)을 4개 수준으로 개발하였다. 또한, 통합 탐구 기능에 대한 학생들의 학습발달과정을 조사하기 위한 도구로 3가지 지구과학 탐구 과제를 개발하였는데, 이들은 학생들이 주어진 문제 인식에서 출발하여 결론 도출에 이르기까지의 통합 탐구 기능을 포함하는 가설-연역적 탐구이다. 중학생, 고등학생, 대학생 총 126명을 대상으로 각각 개발된 지구과학 탐구 과제를 수행하게 한 후 HLP를 토대로 개별 학생들의 통합 탐구 기능을 요소별로 평가하였다. 또한, 학생들의 평가 자료를 Rasch 모델에 적용하여 HLP에 대한 타당화 과정을 거쳤다. 마지막으로, 분석 결과를 근거로 HLP를 수정 보완하여 경험적 학습발달과정을 개발하였다. 이 연구는 학생들의 통합 탐구 기능의 발달에 영향을 주는 요인들을 규명함으로써 지구과학 탐구 수업에서 학생들의 통합 탐구 기능을 효과적으로 향상시키기 위한 스캐폴딩 방안을 찾는데 도움을 줄 수 있을 뿐만 아니라, 지구과학 탐구 수업에 대한 교사들의 PCK를 향상시키는데 필요한 시사점을 제공한다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권9호
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• pp.4127-4131
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• 2015

Background: For HER2 positive metastatic breast cancer (MBC), continuing anti-HER2 therapy beyond progression is associated with improved outcome. However retreatment with trastuzumab after lapatinib progression is controversial. We retrospectively analyzed the efficacy of trastuzumab-based chemotherapy in HER2+ metastatic breast cancer patients whose disease progressed after lapatinib. Materials and Methods: Between October 2010 and May 2013, 54 patients whose disease progressed after lapatinib were retreated with trastuzumab-based chemotherapy. Efficacy and toxicity results were evaluated retrospectively. Results: The median age of patients was 46 (range 27-67). Fourteen patients (26%) had metastases at the time of diagnosis. All of the patients had received trastuzumab in an adjuvant or metastatic setting, while 16 (30%) had received two lines of trastuzumab. All patients had received lapatinib plus capecitabine. The median chemotherapy line for the metastatic setting was 2 (range 1-7). Cranial metastases were identified in 27 (50%) patients. 53 patients received trastuzumab-based chemotherapy following lapatinib progression while one patient received trastuzumab monotherapy. Combination chemotherapy consisted of navelbin (n=33), taxane (n=10), gemcitabine (n=2), platinum (n=2) and platinum with taxane (n=6). The median treatment cycle was 5 (range 1-44). Among 49 patients assessed for response 2 (4%) showed CR, 12 (25%) PR, 11 (22%) SD and 24 (49%) disease progression. Asymptomatic cardiotoxicity was reported in 2 (4%) of the patients. At a median follow-up of 9 months (1-39), median progression-free survival was 5 months (95% CI 4.1-5.9) and median overall survival was 10 months (95% CI 6.9-13.0). PFS and OS were not affected by the absence/presence of cranial metastases. Conclusions: Retreatment with trastuzumab-based therapy after lapatinib progression showed efficacy in heavily treated MBC patients.