초등학교 2, 4 학년 읽기부진 아동의 언어성 작업기억: 비단어 따라말하기, 문장 따라말하기 및 읽기폭 검사를 중심으로

황민아 한국학습장애학회 2016 학습장애연구 Vol.13 No.3

The purpose of this study was to investigate the characteristics of verbal working memory in children with reading difficulties (poor readers) using three measures of working memory; nonword repetition, sentence repetition, and reading span tests. Twenty seven poor readers in grade 2 or 4, and 30 typically developing children of same grades participated in the study. The poor readers performed significantly worse than the typically developing peers in all three measures of verbal working memory. Separate MANOVAs revealed that, in the 4th graders, the poor readers peformed significantly worse than the typically developing peers in all three working memory measures. However, in the 2nd graders, significant group differences were noted in the performances of nonword repeptition and sentence repetition, but not in reading span test. In addition, the poor readers did not show significant developmental changes between the grades in their performances of three working memory tests, whereas typically developing 4th graders performed significantly better than the 2nd graders in nonword repetition and reading span test. The correlation analyses among the scores of working memory measures and reading test scores revealed that in the typically developing children, reading span had significant relation with all three reading skills; word recognition, reading fluency, and reading comprehension. However, in the poor readers, nonword repetition and sentence repetition were significantly related with only reading comprehension. In conclusion, the poor readers exhibited significant difficulties relative to their peers in all three verbal working memory measures regardless of their grades. The poor readers’ developmental growth in working memory skills appeared to be minimal. For the poor readers, the function of phonological loop and episodic buffer might have some relation with reading comprehension. On the other hand, for the typically developing children, the function of central executive appeared to be related to their reading skills in general. 본 연구에서는 비단어 따라말하기, 문장 따라말하기 및 읽기폭 검사를 통해 읽기부진 아동의 언어성 작업기억 능력을 조사하였다. 연구대상은 초등학교 2학년 혹은 4학년에 재학 중인 읽기부진 아동 27명과 같은 학년에 재학 중인 일반 아동 30명이었다. 세 언어성 작업기억 검사 수행 각각에 대한 변량분석에서 읽기부진 아동들은 일반 아동에 비하여 저조한 것으로 나타났다. 세부적으로 중다변량분석 결과에서, 4학년의 경우 세 검사 모두에서 읽기부진 아동과 일반 아동의 집단 차이가 유의미하였으나, 2학년의 경우 두 집단의 차이는 비단어 따라말하기와 문장 따라말하기 수행에서만 유의미하였다. 또한, 일반 아동들의 경우 학년 증가에 따른 비단어 따라말하기와 읽기폭 검사 수행의 향상이 유의미하였지만, 읽기부진 아동들은 세 검사 모두에서 유의미한 학년 간 차이를 보여주지 못하였다. 작업기억 검사와 읽기 검사들 사이의 상관분석 결과, 일반 아동집단에서는 읽기폭 검사가 단어인지, 읽기유창성 및 읽기이해와 상관이 유의미하였고, 문장 따라말하기가 읽기 유창성 및 읽기이해와 유의미한 상관을 보였다. 반면, 읽기부진 아동들은 비단어 따라말하기와 문장 따라말하기가 각각 읽기이해와 유의미한 상관을 보였다. 결론적으로, 읽기부진 아동들의 작업기억 역량은 학년에 관계없이 일반 아동보다 저조하고, 일반 아동과 달리 읽기부진 아동들의 작업기억 능력의 발달적 변화는 미미한 것으로 나타났다. 또한, 읽기수행과 상관을 보이는 작업기억의 요소로 일반 아동들은 중앙집행기의 기능이 읽기능력 전반과 관련성을 보인 반면, 읽기부진 아동 집단에서는 음운루프나 일화버퍼와의 관련성이 읽기이해에서만 관찰되었다.

아동과 성인의 문장이해에서 의미, 조사, 어순단서의 활용 양상

황민아,안혜진 한국인간발달학회 2002 人間發達硏究 Vol.9 No.2

The purpose of the present study was to investigate the sentence comprehension strategies used by Korean-speaking individuals within a framework of competition model. Three- to seven-year-old children and adults participated in the study. In an act-out procedure, the children were asked to determine the agent in sentences composed of two nouns and a verb with varying conditions of three cues(case-marker, animacy, and word-order). The 3-year-old children exhibited a strong reliance on animacy cues as they tended to select animated nouns as the agents. For the 3-year-olds, case-marker cues were the next strong cues followed by word-order cues. The adults relied most on case-markers followed by animacy cues then by word-order cues. As the children's ages increased, the strength of case-marker cues increased while the strength of animacy cues declined. The 4- and 5-year-olds used case-marker cues and animacy cues equivalently. By the age 6, children relied more on case-markers than on animacy cues. For all age groups, word order cues influenced on sentence comprehension only to a small extent. The pattern of sentence interpretation in Korean-speaking children and adults appeared to be consistent with the expectations based on the competition model.

LGR5 and Downstream Intracellular Signaling Proteins Play Critical Roles in the Cell Proliferation of Neuroblastoma, Meningioma and Pituitary Adenoma

황민아,한명훈,박현희,최호진,이규용,이영주,김재민,정진환,류제일,민경환,오영하,고용,고성호 한국뇌신경과학회 2019 Experimental Neurobiology Vol.28 No.5

Leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5) has been reported to play critical roles in the proliferation of various cancer cells. However, the roles of LGR5 in brain tumors and the specific intracellular signaling proteins directly associated with it remain unknown. Expression of LGR5 was first measured in normal brain tissue, meningioma, and pituitary adenoma of humans. To identify the downstream signaling pathways of LGR5, siRNA-mediated knockdown of LGR5 was performed in SH-SY5Y neuroblastoma cells followed by proteomics analysis with 2-dimensional polyacrylamide gel electrophoresis (2D-PAGE). In addition, the expression of LGR5-associated proteins was evaluated in LGR5-inhibited neuroblastoma cells and in human normal brain, meningioma, and pituitary adenoma tissue. Proteomics analysis showed 12 protein spots were significantly different in expression level (more than two-fold change) and subsequently identified by peptide mass fingerprinting. A protein association network was constructed from the 12 identified proteins altered by LGR5 knockdown. Direct and indirect interactions were identified among the 12 proteins. HSP 90-beta was one of the proteins whose expression was altered by LGR5 knockdown. Likewise, we observed decreased expression of proteins in the hnRNP subfamily following LGR5 knockdown. In addition, we have for the first time identified significantly higher hnRNP family expression in meningioma and pituitary adenoma compared to normal brain tissue. Taken together, LGR5 and its downstream signaling play critical roles in neuroblastoma and brain tumors such as meningioma and pituitary adenoma.

사회적 맥락 안에서의 유아의 언어 발달 : 의도적 의사소통이 출현하는 시기를 중심으로

황민아 한국자폐학회 2002 자폐성 장애연구 Vol.3 No.1

한국어/영어 이중언어사용 아동의 한국어 문장이해 : 조사, 의미, 어순 단서의 활용을 중심으로

황민아 한국음성과학회 2003 음성과학 Vol.10 No.4

The purpose of the present study was to investigate the sentence comprehension strategies used by Korean/English bilingual children when they listened to sentences of their first language, i.e., Korean. The framework of competition model was employed to analyze the influence of the second language, i.e., English, during comprehension of Korean sentences. The participants included 10 bilingual children (ages 7;4-13;0) and 20 Korean-speaking monolingual children(ages 5;7-6;10) with similar levels of development in Korean language as bilingual children. In an act-out procedure, the children were asked to determine the agent in sentences composed of two nouns and a verb with varying conditions of three cues(case-marker, animacy, and word-order). The results revealed that both groups of children used the case marker cues as the strongest cue among the three. The bilingual children relied on case-marker cues even more than the monolingual children. However, the bilingual children used animacy cues significantly less than the monolingual children. There were no significant differences between the groups in the use of word-order cues. The bilingual children appeared less effective in utilizing animacy cues in Korean sentence comprehension due to the backward transfer from English where the cue strength of animacy is very weak. The influence of the second language on the development of the first language in bilingual children was discussed.

읽기이해부진 아동의 작업기억 특성: 문장 따라말하기 및 비단어 따라말하기 검사를 중심으로

황민아 한국학습장애학회 2014 학습장애연구 Vol.11 No.1

The purpose of this study was to investigate the characteristics of working memory in children with reading comprehension difficulty(poor comprehender) using a sentence repetition and nonword repetition test. Twelve children with reading comprehension difficulty and 15 typically developing children participated in the study. All children were at grade 3 to 5 in elementary school. The sentence repetition subtest in Kim et. al. (2014) was used in this study. The nonword repetition test included 32 nonwords of 2- to 5-syllable lengths. On the sentence repetition test, the poor comprehenders performed significantly worse than the typically developing children. However, the two groups of children did not differ in their performance on the nonword repetition test. No obvious group differences were observed in the error patterns of the sentence repetition test. Both groups showed a significant main effect of nonword length in their performances on the nonword repetition test, and no interaction effect between group and nonword length was noted. In correlation analyses, the poor comprehenders' sentence repetition performances correlated significantly with expressive vocabulary, and their nonword repetition performances correlated significantly with expressive vocabulary, word decoding and reading comprehension. In the typically developing children, no significant correlations were observed between the working memory measures and the vocabulary/reading measures. It was suggested that the poor comprehenders experienced difficulty in performing sentence repetition test, because it required complex processing of phonology, semantics and grammar of a given sentence and the load of language processing and storage may exceed their working memory capacity with the increasing lengths of sentences. It was also suggested that the poor comprehenders might have intact phonological processing skills and phonological working memory based on their relatively good performances on the nonword repetition test. 본 연구에서는 읽기이해부진 아동의 작업기억 능력을 조사하기 위해 문장 따라말하기 검사와 비단어 따라말하기 검사를 실시하였다. 연구대상은 초등학교 3~5학년에 재학 중인 읽기이해부진 아동 12명과 같은 학년에 재학 중인 일반아동 15명이었다. 문장 따라말하기 검사는 김애화 등(2014)의 문장따라말하기 하위 검사를 사용하였고, 비단어 따라말하기 검사는 2~5음절 길이의 비단어를 길이 별로 8개씩 제작하였다. 연구 결과, 읽기이해부진 아동들은 일반아동에 비하여 문장 따라말하기 수행은 유의미하게 저조하였으나, 비단어 따라말하기 수행은 집단 간 차이가 유의미하지 않았다. 또한, 문장 따라말하기 검사 수행에서 나타난 집단 별 오류 양상은 두 집단 아동들에게서 유사하게 나타났다. 두 집단 아동들 모두 비단어의 길이가 길어질수록 수행 정확도가 유의미하게 감소하였다. 상관분석 결과, 읽기이해부진아동 집단에서는 문장 따라말하기와 표현어휘 사이에, 비단어 따라말하기와 표현어휘, 음독, 짧은글이해 사이에 유의미한 상관이 관찰되었다. 반면, 일반아동 집단에서는 문장 및 비단어 따라말하기 수행과 어휘 및 읽기 검사 수행 사이에 유의미한 상관이 나타나지 않았다. 본 연구 결과, 읽기이해부진 아동들은 음운, 어휘, 문법의 복합적인 처리와 표상이 요구되며 기억 용량의 제한을 받는 문장따라말하기 검사에 있어서는 어려움을 겪지만, 음운 처리 및 음운 기억 능력을 측정하는 비단어 따라말하기 검사에서는 일반아동과 유사하게 수행하는 것으로 나타났다. 이러한 결과는 작업기억 과제의 특성과 읽기이해부진 아동의 언어처리 특성을 기반으로 해석될 수 있다.

언어발달장애 아동의 문법형태소 산출

황민아 한국음성과학회 2003 음성과학 Vol.10 No.3

In the present study, the production of grammatical morphemes of Korean-speaking children with and without developmental language impairments was investigated. Ten children with language impairments (LI) (CA: 4; 4-6; 11, LA: 3; 6-5; 10) and 10 normal children (CA: 3;1-6;3 LA: 3;5-5;11) with matched language abilities participated in the study. Sixty pairs of pictures were used to elicit 12 types of predetermined grammatical morphemes. The two pictures of a pair were designed to elicit two sentences of the same sentence structure. After the investigator described one picture of a pair; the children were asked to describe the other picture. The LI children made more errors than the normal children in the production of 6 types of grammatical morphemes including; locative case marker, derive case marker, two connective endings of predicates representing cause and goal, and suffixed for passive and causative verbs. However, the LI children produced some grammatical morphemes as accurately as the normal children. The two groups were similar in their error patterns. Some explanations for Korean-speaking LI children's use of grammatical morphemes were suggested.

단순언어장애아동의 문장 이해

황민아(Mina Hwang) 한국언어청각임상학회 2003 Communication Sciences and Disorders Vol.8 No.3

본 연구에서는 한국어를 사용하는 단순언어장애아동들이 세 가지 단서(조사, 어순, 생물성)를 체계적으로 조작한 문장을 이해할 때, 세 단서를 활용하는 양상과 그 정도를 언어연령이 일치된 정상아동들, 그리고 생활연령이 일치된 정상아동들과 비교하였다. 단순언어장애아동들이 세 단서 각각을 활용하는 양상은 정상아동들의 양상과 유사하였으나 그 정도에서는 차이가 있었다. 단순언어장애아동들은 두 정상아동집단보다 생물성단서에 의존하는 정도가 유의미하게 높았고, 조사단서를 활용하는 정도는 언어연령이 일치된 아동들과는 유사하나 생활연령이 일치된 아동들보다는 유의미하게 낮았다. 즉, 단순언어장애아동들이 조사단서를 처리하는 능력은 언어능력이 비슷한 정상아동과는 다르지 않지만, 상대적으로 의미적 단서인 생물성단서에 의존하는 경향이 크기 때문에 이들은 문장이해에서 의미적 단서의 영향을 정상아동들보다 더 많이 받는다고 볼 수 있다. The purpose of the present study was to investigate the sentence comprehension strategies used by Korean-speaking children with specific language impairment(SLI) within a framework of competition model. Fourteen children with SLI(SLI children)(ages 4;7- 7;2) and 14 age-matched normal children(CA children), and 14 younger children with matching language ages(LA children) participated in the study. In an actout procedure, the children were asked to determine the agents in sentences composed of two nouns and a verb with varying conditions of three cues(case-marker, animacy, and word-order). The results of group comparisons revealed that the SLI children relied animacy cues significantly more than the other two groups of normal children, and the two normal groups did not differ from each other in the use of animacy cues. In terms of case-marker cues, the CA children relied on case-marker cues significantly more than the other two groups, and the SLI children did not differe from the LA children. There were no significant differences between the groups in the use of word-order cues. The results indicated that although the SLI children use case-marker cues as much as the normal children with similar language skills, they tend to rely more on animacy cues when animacy cues are available.

읽기이해부진아동의 어휘판단에서 단어길이 효과

황민아(Mina Hwang),최경순(Kyung-Soon Choi) 한국언어청각임상학회 2011 Communication Sciences and Disorders Vol.16 No.4

배경 및 목적: 읽기장애아동의 단어해호화 과정의 특성을 실시간(on-line)으로 측정한 연구들은 난독증 아동들에 집중되어 진행된 반면, 음독능력이 정상범주에 속하는 읽기이해부진아동들에 대한 연구는 드물었다. 자소-음소 전환이 규칙적인 언어들의 경우 단어 음독의 정확도가 아니라 속도가 읽기이해와 상관이 있다는 선행연구에 근거하면 읽기이해부진아동들의 음독 정확도가 일반아동들과 유사하더라도 단어를 읽고 재인하는 속도는 일반아동들에 비해 느릴 수 있다. 본 연구에서는 읽기이해부진아동들이 단어를 읽고 재인하는 과정의 실시간 특성을 밝히고자 하였다. 방법: 연구대상은 초등학교 4학년의 읽기이해부진아동 10명과 일반아동 12명이었다. 단어재인과정에서 단어 길이의 효과를 측정하기 위해 2음절과 4음절 단어에 대한 어휘판단 과제를 실시하였다. 결과: 읽기이해부진아동은 어휘판단의 반응 정확도와 반응속도 모두에서 일반아동에 비하여 유의미하게 저조한 수행을 보였다. 단어 길이 효과는 두 집단 아동들 모두에서 나타났지만, 읽기부진아동에게서 유의미하게 더 크게 나타났다. 논의 및 결론: 읽기이해부진아동들은 표준화된 읽기 검사에서 실시한 음독의 정확도가 일반아동들과 유사하였다. 그럼에도 불구하고, 본 연구의 어휘판단 과제에서 일반아동에 비하여 단어를 읽고 재인하는 정확도가 떨어지고, 속도가 느렸으며 이러한 경향은 긴 단어에서 더욱 강력하게 나타났다. 이러한 결과는 본 연구에 참가한 읽기이해부진아동들이 읽기이해 뿐 아니라 단어재인에서도 일반아동들에 비해 어려움을 겪는다는 것을 의미한다. 한글과 같이 자소-음소 전환이 규칙적인 언어에서 단어해호화 능력의 발달을 측정할 때 음독의 정확도만을 기준으로 삼는 것의 제한점과 이에 따른 읽기장애 분류의 문제점에 대하여 논의하였다. Background & Purpose: Although there have been many studies investigating the on-line word-decoding process during reading in dyslexic children using various languages, studies on word-decoding skills of children with poor reading comprehension are limited. Poor comprehenders are supposed to have normal word-decoding skills based on their accuracy scores in standardized word-reading tests. Reportedly, for children learning to read languages with transparent grapheme-phoneme correspondence, their reading comprehension is highly correlated with reading speed but not with the accuracy of word-reading. Since the graphemephoneme correspondence of the Korean language is known to be transparent, it is possible that Korean poor comprehenders are slower in recognizing words relative to typically developing children even though the accuracy of word-reading is similar in the two groups. Methods: Ten poor comprehenders and 12 typically developing children in 4th grade participated in the present study. The children performed a lexical decision task on words with two different lengths, two syllables or four syllables. Results: The poor comprehenders were significantly slower and less accurate in their performances on the lexical decision task. The word-length effect was significantly greater in the poor comprehenders, as the differences in speed and accuracy of lexical decision between short and long words were greater in the poor comprehenders compared to the typically developing children. Discussion & Conclusion: In a standardized reading test, the poor comprehenders only exhibited reading comprehension difficulties and were similar to the typically developing children in word-reading accuracy. However, the poor comprehenders' performances in the lexical decision task indicated they also had difficulties in word-recognition. The authors of the present study suggest that, in a language with transparent grapheme-phoneme correspondence, like the Korean language, using word-reading accuracy as a measure of word-decoding skills may not be appropriate. The importance of cross-linguistic differences of reading development in diagnosing various types of reading disabilities is also discussed in the present paper.

Dynamic Droop-based Inertial Control of a Wind Power Plant

황민,전영환,박정욱,강용철 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

The frequency of a power system should be maintained within the allowed limits for stable operation. When a disturbance such as generator tripping occurs in a power system, the frequency is recovered to the nominal value through the inertial, primary, and secondary responses of the operating synchronous generators (SGs). However, for a power system with high wind penetration, the system inertia will decrease significantly because wind generators (WGs) are operating decoupled from the power system. This paper proposes a dynamic droop-based inertial control for a WG. The proposed inertial control determines the dynamic droop depending on the rate of change of frequency (ROCOF). At the initial period of a disturbance, where the ROCOF is large, the droop is set to be small to release a large amount of the kinetic energy (KE) and thus the frequency nadir can be increased significantly. However, as times goes on, the ROCOF will decrease and thus the droop is set to be large to prevent over-deceleration of the rotor speed of a WG. The performance of the proposed inertial control was investigated in a model system, which includes a 200 MW wind power plant (WPP) and five SGs using an EMTP-RV simulator. The test results indicate that the proposed scheme improves the frequency nadir significantly by releasing a large amount of the KE during the initial period of a disturbance.