• 자원환경지질
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• 제35권3호
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• pp.273-284
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• 2002

인공위성 레이더고도 측정값으로부터 유도된 중력이상으로턱터 남극 드레이크해협의 해저지형을 계산하기 위해 Gravity-Geologic Method(GGM)를 적용하였다. 총 6548개의 음항측심자료 중 2/3는 control depth로, 나머지는 결과 검증을 위한 check point 자료로 이용하였다. 효과적인 계산을 위해 해수와 해저지형의 밀도차이는 check point를 이용, 9.0 gm/㎤로 가정하였다. Control depth로부터 광역중력이상을 계산하였고, 이를 Sandwell & Smith(1997)의 중력이상으로부터 제거하여 해저지형의 기복에 의한 중력 효과를 계산하였으며, 이로부터 해저지형을 복원하였다. Selective Merging 기법을 개발하여 복원된 해저지형과 고주파 측심자료를 효과적으로 합성하였다. 복원된 해저지형은 한국해양연구원의 측심자료, GEODAS 및 전지구 모델 ETOPO5 결과와 각각 0.91, 0.92, 0.85의 상관계수를 갖으며, Selective Merging을 이용한 최종 결과는 GEODAS 및 Smith Sandwell(1997)의 결과와 각각 0.948 및 0.954의 상관관계 및 449.8, 441.3 m의 RMS 오차를 갖는다. GGM을 이용하여 계산된 해저지형은 측심이 충분히 이루어지지 않은 지역의 경우 전지구모델(ETOPO5)이나 자료의 양이 불충분한 음항측심에 의한 결과보다 우수한 것으로 나타났다.

• 충청수학회지
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• 제25권3호
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• pp.475-489
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• 2012

A plateau in a Motzkin path is a sequence of three steps: an up step, a horizontal step, then a down step. We find three different forms for the bivariate generating function for plateaus in Motzkin paths, then generalize to longer plateaus. We conclude by describing a further generalization: a continued fraction form from which one can easily derive new multivariate generating functions for various kinds of path statistics. Several examples of generating functions are given using this technique.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.219-225
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• 2000

This study is to develop a Fe-based disc brake lining with sponge structure for rolling stock of 150km/h train and to concept design with 3 groove type for brake disc reducing hot hair-crack and certainly friction coefficient. The developing brake lining would be to presumption of saving 300 million won during one year

• 대한자원환경지질학회:학술대회논문집
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• 대한자원환경지질학회 2000년도 춘계공동학술발표회
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• pp.305-307
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• 2000

• 한국지구과학회:학술대회논문집
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• 한국지구과학회 2005년도 추계학술발표회 논문집
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• pp.136-141
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• 2005

The K Ar ages, whole rock geochemistry and Sr Nd Pb isotopes have been determined for the submarine basalts dredged from the P2 and P3 segments of the Antarctic-Phoenix Ridge (APR), Drake Passage, Antarctica, for better understanding on temporal variation of magma chemistry in association with extinction of seafloor spreading. The fossilized APR is distant from the known hot spots, and consists of older N-MORB prior to extinction of spreading and younger E-MORB after extinction. The older N-MORB (3.5-6.4 Ma) occur in the southeast flank of the P3 segment (PR3) and the younger E-MORB (1.4-3.1 Ma) comprise a huge seamount at the P3 segment (SPR) and a big volcanic edifice at the P2 segment (PR2). The N-type PR3 basalts have higher Mg#, K/Ba, and CaO/Al2O3 and lower Zr/Y, Sr, and Na8.0 with slight enrichment in incompatible elements and almost flat REE patterns. The E-type SPR and PR2 basalts are highly enriched in incompatible elements and LREE. The extinction of spreading occurring at 3.3 Ma seems to have led to a temporal magma oversupply with E-MORB signatures. Geochemical signatures such as Ba/TiO2, Ba/La, and Sm/La suggest heterogeneity of upper mantle and formation of E-MORB by higher contribution of enriched materials to mantle melting, compared to N-MORB environment. E-MORB magmas beneath the APR seem to have been produced by low melting degree (up to 1% or more) at deeper low-temperature regime, where metasomatized veins consisting of pyroxenites have preferentially participated in the melting. The occurrence of E-MORB at the APR is a good example to better understand what kinds of magmatism would occur in association with extinction of spreading.

• 공학교육연구
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• 제10권3호
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• pp.5-20
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• 2007

본 연구에서는 교육과정 설계모형에 기초하여 기계공학부의 전공교육과정 중 공학설계 교육과정의 설계방식을 분석하고자 하였다. 이를 위하여 Drake & Burns(2004)가 제시한 교육과정 조직요소간의 관계모형과 Toohey(1999)의 대학교육과정 설계유형을 분석의 틀로 활용하였다. 교육과정의 조직요소간의 관계와 설계유형을 분석한 결과는 다음과 같다. 첫째, 교육과정 조직요소간의 관계는 각 과목의 교육목표를 달성하기 위하여, 설계의 구체적 정보, 주제와 주요 개념의 순서로 관련된 지식을 습득하고, 공학설계에 관련된 기초기능, 범학문적 기능과 고급 기능을 순차적으로 향상시킬 수 있게 설계되어 있다. 둘째, 분석대상인 창의적 공학설계, 설계 및 제작과제와 졸업설계 및 제작과제의 교육과정 설계유형은 프로젝트, 탐구, 문제 중심설계의 형태를 취하고 있다. 본 연구결과는 공학설계 교육과정의 교육내용들 간의 연계성을 검토하기 위한 기초 자료로 활용될 수 있을 것이다.

• Ocean and Polar Research
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• 제25권4호
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• pp.625-631
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• 2003

While phytoplankton diversity and productivity in the Southern Ocean has been widely studied in recent years, most attention has been given to elucidating environmental factors that affect the dynamics of micro-plankton (mainly diatoms) and nano-plankton (mainly Phaeocystis antarctica). Only limited effects have been given to studying the occurrence and the potential risks associated with the blooming of dinoflagellates in the relevant waters. This study focused on the appearance and toxicological characteristics of a toxic dinoflagellate, Alexandrium tamarense, identified and isolated from the Drake Passage in a research cruise from November to December 2001 The appearance of A. tamarense in the Southern Ocean indicates the risk of a paralytic shellfish poisoning (PSP) outbreak there and is therefore of scientific concern. Results showed that while the overall quantity of A. tamarense in water samples from 30meters below the sea surface often comprised less than 0.1% of the total population of phytoplankton, the highest concentration of A. tamarense (20 cells $L^{-1}$) was recorded in the portion of the Southern Ocean between the southern end of South America and the Falkland Islands. Waters near the Polar Front contained the second highest concentrations of 10-15 cells $L^{-1}$. A. tamarense was however rarely found in waters near the southern side of the Polar Front, indicating that cold sea temperatures near the Antarctic ice does not favor the growth of this dinoflagellate. One strain of A. tamarense from this cruise was isolated and cultured for further study in the laboratory. Experiments showed that this strain of A. tamarense has a high tolerance to temperature variations and could survive at temperatures ranging from $5-26^{\circ}C$. This shows the cosmopolitan nature off. tamarense. With regard to the algal toxins produced, this strain of A. tamarense produced mainly C-2 toxins but very little saxitoxin and gonyailtoxin. The toxicological property of this A. tamarense strain coincided with a massive death of penguins in the Falkland Islands in December 2002 to January 2003.

• 한국수학교육학회지시리즈A:수학교육
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• 제63권2호
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• pp.139-163
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• 2024

The purpose of this study is to examine the capabilities of ChatGPT as a tool for supporting students in generating mathematical arguments that can be considered proofs. To examine this, we engaged students enrolled in a mathematics pathways course in evaluating and revising their original arguments using ChatGPT feedback. Students attempted to find and prove a method for the area of a triangle given its side lengths. Instead of directly asking students to prove a formula, we asked them to explore a method to find the area of a triangle given the lengths of its sides and justify why their methods work. Students completed these ChatGPT-embedded proving activities as class homework. To investigate the capabilities of ChatGPT as a proof tutor, we used these student homework responses as data for this study. We analyzed and compared original and revised arguments students constructed with and without ChatGPT assistance. We also analyzed student-written responses about their perspectives on mathematical proof and proving and their thoughts on using ChatGPT as a proof assistant. Our analysis shows that our participants' approaches to constructing, evaluating, and revising their arguments aligned with their perspectives on proof and proving. They saw ChatGPT's evaluations of their arguments as similar to how they usually evaluate arguments of themselves and others. Mostly, they agreed with ChatGPT's suggestions to make their original arguments more proof-like. They, therefore, revised their original arguments following ChatGPT's suggestions, focusing on improving clarity, providing additional justifications, and showing the generality of their arguments. Further investigation is needed to explore how ChatGPT can be effectively used as a tool in teaching and learning mathematical proof and proof-writing.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2017년도 춘계 종합학술대회 논문집
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• pp.53-54
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• 2017

랩 음악은 장르 특성상 곡에서 가사의 중요성이 매우 크고, 가사 전달을 리듬 중심으로 하기 때문에 가사의 리듬, 운율이 부각된다. 랩 음악 가사의 내용과 운율에 대해 살펴보기 위해 지난 10년간 랩 음악 장르에서 전 세계적으로 가장 큰 인기를 얻고 있는 작사가 겸 가수Drake 와 Lil Wayne 의 곡 23곡을 선정하여 그 내용과 가사 운율을 살펴본다. 내용은 공통적으로 과시를 가장 많이 사용하였으며, 사랑, 유흥 등의 가사에서는 두 작사가의 차이를 보였다. 운율은 두 작사가 모두 규칙적 운율을 주로 사용하였으며, 그 안에 여러 가지 방법을 통해 불규칙성을 더했고, 그 방법을 사용하는 빈도가 다름으로서 운율 사용방식의 차이점을 보였다.

• 대한교통학회지
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• 제14권2호
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• pp.7-29
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• 1996

Traffic flow characteristics is analysed on eight multi-lane roads which are unsignalized in urban areas. Data of traffic flow rates by classification and average speed were gathered every ten minutes interval for twenty-four hours. Machine (NC-90A) was used to acquire the field data. The major purpose of this study is to build up speed-density models on urban arterial roads. Five different kinds of models were tested. Those models are Greenshields' model, Greenberg's model, modified Greenberg's model, Underwood's model and Drake's model. The modified Greenberg's model fits best at six points and the Greenshield's model fits best two points out of eight points. The breakpoint(Kb) of modified Greenberg's model is between 10 and 32 pcphpl. Capacity drawn from speed-volume relationships were appeared to be arround 2,000 and 2,200 pcphpl at the Hannam Bridge and the Hannam Overpass and 1,100 and 1,700 pcphpl at Namsan Tunnel(No1) and the beginning point of Gyeong-Bu Expressway.