시판되는 에너지음료의 법랑질 침식효과에 대한 연구

정문진 ( Moon Jin Jeong ),정순정 ( Soon Jeong Jeong ),손정희 ( Jung Hui Son ),정성균 ( Sung Kyun Chung ),김아름 ( A Reum Kim ),강은주 ( Eun Ju Kang ),김은주 ( Eun Ju Kim ),김혜인 ( Hye In Kim ),장고은 ( Ko Eun Jang ),조민희 ( Min 한국치위생과학회 2014 치위생과학회지 Vol.14 No.4

To find out the effect of commercially available energy drinks on tooth enamel erosion, analyzed pH, buffering capacity, and the content of some of the inorganic components selecting 4 energy drinks that has high affinity of the products currently being sold. In addition, by observing the degree of erosion before and after immersion in energy drink by surface microhardness and scanning electron microscope (SEM) the results were as follows: Acidity of energy drink ?Burn Intense? was the lowest as 2.78±0.01 highest on distilled water as 6.475±0.01. ?Burn Intense? buffering capacity was 3.48±0.155 at pH 5.5, 1.88±0.15 at pH 7.0 which is the highest, and ?Hot6? was 1.71±0.37, 1.23±0.35 on each of it showing the lowest points. Ca content on energy drink was the highest at ?Volt Energy? as (77.21±2.70 mg/kg), the lowest at ?Hot6? as (0.98±0.05 mg/kg). P content was the highest on ?Hot6?(1.34±0.05 mg/kg) and detected at ?Red Bull?. Enamel surface hardness variation of the energy drinks before and after immersion showed rapid decrease at ?Red Bull? (66.65±35.60), and ?Volt Energy? (61.96±31.42), ?Burn Intense? (58.53±24.84), ?Hot6? (53.99±60.26) was in order. Distilled water, the control group, showed significant difference with the experimental group (p<0.05). But there was no significant difference between energy drinks. At SEM observation and analysis, ?Burn Intense? was the most severe demineralization, ?Volt Energy?, ?Hot6?, ?Red Bull?, distilled water was in order. In the above results, taken together there were no statistically differences between energy drinks but significant difference in comparison with distilled water. In addition, at SEM observation and analysis all energy drink caused dental erosion, especially ?Burn Intense?, has the lowest acidity, was serious. Thus, it is believed to provide a variety of oral health education and information about energy drinks that can affect the erosion of the teeth so public have the right to be recognized and reasonable dental care.

간세포암 환자에서 경간동맥화학색전술 후 혈장 Insulin-Like Growth Factor-II의 변화와 전이와의 연관성

송병철(Byung Cheol Song),정영화(Young Hwa Chung),김정아(Jung A Kim),양수현(Soo Hyun Yang),이한주(Han Chu Lee),윤현기(Hyun Ki Yoon),성규보(Kyu Bo Sung),정성애(Sung Ae Jung),유권(Kwon Yoo),이영상(Young Sang Lee),서동진(Dong Jin Suh) 대한소화기학회 2000 대한소화기학회지 Vol.36 No.3

N/A

쿠레레(Currere) 방법에서의 교육의 원리

정성아(Jung, Sung-A) 한국교육사상연구회 2006 敎育思想硏究 Vol.20 No.-

본 연구는 Pinar와 Grumet가 제안한 교육과정 재개념화로서의 쿠레레 방법이 가지는 교육의 원리를 분석해 냄으로써 쿠레레 방법의 적용을 위한 실제적인 안내지침을 마련하고 이것이 가지는 교육적 함의를 살펴보는 데 그 목적이 있다. 이를 위해서 쿠레레 방법의 이론적 기반이라 할 수 있는 정신분석학, 현상학, 실존주의, 해석학에 대해 분석하였으며, 이러한 이론적 기반에 기초하여 쿠레레 방법에 내재된 지식관과 학생관, 교사관을 살펴보았고, 이를 통해 쿠레레 방법이 가지는 교육원리를 추출하였다. 연구의 결과, 쿠레레 방법은 첫째, 자신의 삶과 자기 자신에 대한 이해의 원리 둘째, 학생 개개인이 가지는 경험의 고유성의 원리 셋째, 인식 주체와 인식대상 간의 변증법적 관계로서의 지식과 의미 구성의 원리 넷째, 자율성의 원리 다섯째, 교사와 학생간, 학생과 학생간의 학습공동체의 원리에 의해 이루어진다고 할 수 있다. The purpose of this study was to find the educational significance of Currere, suggested by Pinar and Grumet as a methodological model of curriculum reconceptualization. Firstly, in the analysis of theoretical backgrounds of Currere, the researcher came to know that this is based on psychoanalysis, phenomenology, existentialism, and hermeneutics, and among them phenomenology, existentialism, and hermeneutics were not separated and were emphasized repeatedly in all the steps of Currere. Secondly, pedagogical principles based on the theoretical backgrounds were as follows. The first principle was the principle of understanding. Currere is a process in which students analyze their current educational experience, and understand themselves and their lives. The second one was the principle of idiosyncrasy. In Currere, each student's idiosyncrasy had to be respected. The third one was the principle of knowledge construction. In Currere, knowledge was constructed in the constant dialectic relationships between the knower and the known. The fourth one was the principle of autonomy. The fifth one was the principle of learning community. This principle worked in all steps of Currere and emphasized open and trusting learning climate between students and teachers. The results of this study had an academic significance in respects that they give applicable Currere guidelines in real teaching contexts. Moreover, the pedagogical principles of Currere had an educational significance in curriculum and instruction by making students' lives and experience the focus of education, providing opportunities to form students' self-identity, trying to integrative development of the knowing and the doing, and applying to Moral education, Korean language education and extra curriculum.

불면의 두침치료에 대한 임상논문 고찰 -1994년부터 2011년까지 중국 논문을 중심으로-

유춘길 ( Chun Gil Ryu ),김수정 ( Soo Jung Kim ),조아람 ( A Ram Cho ),서주희 ( Joo Hee Seo ),정성식 ( Seong Sik Jeong ),이지수 ( Ji Su Lee ),성우용 ( Woo Yong Sung ) 대한한방신경정신과학회 2012 동의신경정신과학회지 Vol.23 No.1

Objectives : The study was designed to evaluate the effects of scalp acupuncture treatment on patients with insomnia in China. Methods : A journal search was performed using China National Knowledge Infrastructure(CNKI) from 1994 to 2011. Key words used within the search were ``insomnia`` and ``scalp acupuncture``. Results : 19 studies were selected. 9 RCTs and 2 case control studies showed that scalp acupuncture therapy reported better results than routine acupuncture, western medicine, and herbal medicine therapy. 8 case reports described a significant improvement in patients with insomnia by scalp acupuncture. Conclusions : There have been many studies regarding scalp acupuncture on patients with insomnia in China and these studies can be applied to clinical practices within Korea.

갑상선기능항진증의 간소엽중심부 간세포손상의 진단적 평가를 위한 isocitrate dehydrogenase 활성도 측정

최원범(Won Bum Choi),정영화(Young Hwa Chung),정성애(Sung Ae Jung),송병철(Byung Cheol Song),김정아(Jeong A Kim),김정원(Jung Weon Kim),송일한(Il Han Song),장우영(Woo Young Chang),송영기(Young Kee Shong),이영상(Yung Sang Lee),서동진(Don 대한내과학회 2000 대한내과학회지 Vol.58 No.2

N/A Background : The zonal differentiation of hepatic necrosis is important in the aspect of treatment, follow-up and prognosis of patients. The purpose of this study was evaluating the clinical usefulness of serum isocitrate dehydrogenase (ICDH) as a marker of centrilobular hepatic necrosis in patients with hyperthyroidism. Methods : We determined the serum ICDH and alanine aminotransferase (ALT) activities in 56 patients with hyperthyroidism, 16 patients with chronic viral hepatitis, and 17 normal controls. Results : The activities of serum ICDH were significantly higher in patients with hyperthyroidism than those of patients with chronic viral hepatitis or normal control (p<0.01), even though those of serum ALT were higher in patients with chronic viral hepatitis (p<0.01). The ratio of serum ICDH and ALT activities were markedly different between the patients with hyperthyroidism and chronic viral hepatitis (p<0.001). There was a significant correlation between the serum ICDH and ALT activities in patients with hyperthyroidism as well as in those with chronic viral hepatitis (p<0.05). In patients with hyperthyroidism, the serum ICDH levels were more significantly correlated with serum triiodothyronine (T3) than thyroxine (T4) levels. In a patients with hyperthyroidism and elevated ALT levels, the serum ICDH activity decreased progressively and was normalized ultimately, as serum ALT level and thyroid function were normalized with antithyroid medication. Conclusion : The serum ICDH or ratio of serum ICDH and ALT activities might be useful clinically in differentiating the centrilobular from periportal hepatic necrosis, and following up the degree of hepatic necrosis in patients with hyperthyroidism.(Korean J Med 58:189-196, 2000)

경영자 인센티브 스톡옵션의 민감도와 기업의 위험관리 특성

정성창(Jung, Sung Chang),김현아(Kim, Hyeon A) 한국경영학회 2015 한국경영학회 통합학술발표논문집 Vol.2015 No.08

본 연구는 경영자에게 인센티브 스톡옵션을 부여한 유가증권시장 상장기업을 대상으로 주식가격 및 주식수익률 변동성에 대한 옵션가치 변화의 민감도인 델타와 베가가 기업의 파생상품을 활용한 위험헤징전략에 미치는 영향력을 살펴보았다. 델타가 클수록 경영자는 위험회피적인 의사결정을 하므로 헤징의 크기를 늘릴 것이며, 베가가 클수록 경영자는 보다 위험을 추구하고자 헤징을 줄이거나 하지 않을 것이다. 2004년부터 2011년까지 총 703개 패널 데이터를 대상으로 분석한 결과, 총델타가 클수록 파생상품을 사용한 것으로, 총베가가 클수록 파생상품을 활용하지 않은 것으로 나타났다. 그리고 총델타가 클수록 위험헤징 목적의 파생상품 계약금액의 크기는 유의적으로 증가한 반면 총베가가 클수록 파생상품 계약금액의 크기는 유의하지는 않지만 부(-)의 값으로 나타났다. 본 연구의 결과는 경영자가 인센티브 스톡옵션을 부여받은 경우 그들의 부를 극대화 하고자 하는 사적 이익 추구 행위가 기업의 위험관리전략에 영향을 미치며, 이는 또 다른 대리인 비용으로서 경영자 보상설계 시 고려되어져야 할 것으로 판단되었다. This study explores whether executive stock options(ESOs) provide managers with risk preferences to maximize their wealth and affect hedging activities. Because there is a direct link between options and stock price, managers have an incentive to utilize derivatives to avoid risk. In contrast, they are likely to decrease the hedging activities in that the value of an manager’s stock option portfolio increases with the volatility of the firm’s stock returns. We measure the opposing effects of stock options on their wealth with the two sensitivities of options?Total sensitivity to stock price(TDelta) and Total sensitivity of stock return volatility(TVega). We analyzed a total of 703 firm panel data whose executives are holding stock options, selected from the listed companies in Korea Stock Exchange(KSE) from year 2004 to year 2011. In univariate analysis, these data are categorized into two groups by the risk hedging with derivatives ? ‘derivatives are used’ (n=290), ‘derivatives are not used’(n=413). The results are like followings; Firstly, according to the univariate analysis between groups of derivatives used versus nonused, Tdelta is significantly higher and Tvega is statistically lower for the group of derivatives used. Secondly, in the logit analysis, Tdelta affects positively the usage of derivatives, which means that mangers avoid risk by utilizing derivatives more if their sensitivities of option value to stock price is higher. In contrast, Tvega has an negative effect on the usage of derivatives, implying that derivatives are less used to take risk as Tvega is increasing. Lastly, in the tobit analysis where dependent variable is the contract value of derivatives scaled by firm size, the same results have been found. But there is evidence that managers are more active in risk hedging than risk taking. This study has an significance in that this is the first in Korea to explore the relationship empirically between sensitivity of managers’ stock option portfolios to stock price and the sensitivity of their portfolios to stock return volatility and risk hedging strategies. Still more this study’s measures are more sophisticated than prior research, because the sensitivities are calculated under the full information method.

경영자 인센티브 스톡옵션의 민감도와 기업의 위험관리 특성

정성창(Sung-Chang Jung),김현아(Hyeon-A Kim) 한국산업경제학회 2015 산업경제연구 Vol.28 No.6

본 연구는 경영자에게 인센티브 스톡옵션을 부여한 기업을 대상으로 그들의 스톡옵션가치 변화의 민감도인 델타와 베가가 기업의 파생상품을 활용한 위험헤징전략에 미치는 영향력을 살펴보았다. 스톡옵션의 델타가 클수록 경영자는 위험회피적인 의사결정을 하므로 헤징의 크기를 늘릴 것이며, 베가가 클수록 경영자는 보다 위험을 추구하고자 헤징을 줄이거나 하지 않을 것이다. 구체적으로 보면, 옵션가격을 결정짓는 두 요인(주식가격, 주식가격 변동성)의 변화에 대한 옵션가치의 변화(델타, 베가)를 측정한 후, 각 기업별로 보유 중인 경영자 스톡옵션 수를 반영하여 총민감도를 산출하였다. 그리고 로짓 및 패널 토빗분석을 통해 이러한 총민감도가 위험회피목적의 파생상품 활용에 미치는 영향을 살펴보았다. 2004년부터 2011년까지 총 703개 패널 데이터를 대상으로 하였으며, 이 중 290개가 파생상품을 위험헤지 목적으로 활용한 기업이었다. 분석 결과, 총델타가 클수록 파생상품을 더 사용한 것으로, 총베가가 클수록 파생상품을 활용하지 않은 것으로 나타났다. 그리고 총델타가 클수록 위험헤징 목적의 파생상품 계약금액의 크기는 유의적으로 증가한 반면 총베가가 클수록 파생상품 계약금액의 크기는 유의하지는 않지만 부(-)의 값으로 나타났다. 즉, 경영자는 보유 중인 스톡옵션의 가치를 극대화하기 위해 주식가격 및 주식수익률 변동성에 대해 다른 태도를 보이며, 이는 파생상품을 활용한 헤징의 크기에 영향을 미치는 것으로 판단되었다. 본 연구의 결과는 경영자가 인센티브 스톡옵션을 부여받은 경우 그들의 부를 극대화 하고자 하는 사적 이익 추구 행위가 기업의 위험관리전략에 영향을 미치며, 이는 또 다른 대리인 비용으로서 경영자 보상설계 시 고려되어져야 할 것으로 생각되었다. 한편 국내 대기업의 경우 대주주 중심의 지배구조이기 때문에 이러한 경영자의 사적이익추구행위는 지배구조의 영향을 받을 수 있다. 본 연구는 이러한 한계점을 추후 연구에서 보완하겠다. This study explores whether executive stock options(ESOs) provide managers with risk preferences to maximize their wealth and affect hedging activities. Because there is a direct link between options and stock price, managers have an incentive to utilize derivatives to avoid risk. In contrast, they are likely to decrease the hedging activities in that the value of managers’ stock option portfolio increase with the volatility of the firm’s stock returns. Firstly, we measure the opposing effects of stock options on their wealth with the two sensitivities of options–Total sensitivity to stock price(TDelta) and Total sensitivity of stock return volatility(TVega). Then, we explore how TDelta and TVega have impacts on the derivatives usage through panel Logit and panel Tobit analysis. We analyzed a total of 703 firm panel data whose executives are holding stock options, selected from the listed companies in Korea Stock Exchange(KSE) from year 2004 to year 2011. In univariate analysis, these data are categorized into two groups by the risk hedging with derivatives – ‘derivatives are used’ (n=290), ‘derivatives are not used’(n=413). The results are like followings; Firstly, according to the univariate analysis between groups of derivatives used versus non-used, Tdelta is significantly higher and Tvega is statistically lower for the group of derivatives used. Secondly, in the logit analysis, Tdelta affects positively the usage of derivatives, which means that mangers avoid risk by utilizing derivatives more if their sensitivities of option value to stock price is higher. In contrast, Tvega has an negative effect on the usage of derivatives, implying that derivatives are less used to take risk as Tvega increases. Lastly, in the tobit analysis where dependent variable is the contract value of derivatives scaled by firm size, the same results have been found. But there is evidence that managers are more active in risk hedging than risk taking. This study has an significance in that this is the first in Korea to explore the relationship empirically between sensitivity of managers’ stock option portfolios to stock price and to stock return volatility and risk hedging strategies. Still more this study’s measures are more sophisticated than prior research, because the sensitivities are calculated under the full information method. In the following research, this study would supplement the limitation that it didn’t consider the possibility of corporate governance affecting the Managerial Opportunism. Particularly in a leading conglomerate in Korea, employed managers can have a weak decision-making power in hedging strategies due to its major shareholder’s ownership.

이어도 해양종합과학기지에서의 3차원 바람성분에 따른 에어로솔 수 농도 변동 특성

박성화(Sung-Hwa Park),장상민(Sang-Min Jang),이동인(Dong-In Lee),정운선(Woon-Seon Jung),정종훈(Jong-Hoon Jung),정성아(Sung-A Jung),정창훈(Chang Hoon Jung),김경식(Kyungsik Kim),김경익(Kyung-Eak Kim) 한국기상학회 2012 대기 Vol.22 No.1

Volume-Controlled Mode의 기계환기시 동일환 I:E Ratio하에서 Inspiratory Pause가 기도압 몇 가스교환에 미치는 영향

최원준,정성한,이정아,최강현,Choi, Won-Jun,Jung, Sung-Han,Lee, Jeong-A,Choe, Kang-Hyeon 대한결핵및호흡기학회 1998 Tuberculosis and Respiratory Diseases Vol.45 No.5

연구배경: Volume controlled ventilation(VCV)시 inspiratory pause의 사용은 흡기시간을 연장하여 평균기도압을 상승시키고 가스교환을 호전시키는 것으로 알려져 있다. 그러나 같은 흡기시간을 유지하더라도 inspiratory pause를 사용하였을 경우 평균기도압과 가스교환의 변화에 대하여는 잘 알려지지 않았다. 방 법: 저자들은 VCV으로 기계호흡을 받는 12명의 환자를 대상으로 흡기산소농도, 상시호흡량, 호흡수 및 I : E ratio(1 : 3)는 변화시키지 않고 5%의 pause를 사용한 경우와 사용하지 않은 경우의 기도압 및 가스교환의 변화를 관찰하여 비교하였다. 결 과: 동맥혈 이산화탄소분압은 pause를 사용한 경우 $38.6{\pm}7.4$ mmHg로 시용하지 않은 경우의 $41.0{\pm}7.7$ mmHg보다 유의하게 낮았다 (p<0.01). 동맥혈 산소분압은 pause를 사용한 경우 $94.4{\pm}23.2$ mmHg로 사용하지 않은 경우의 $91.8{\pm}19.7$ mmHg보다 높은 경향이 있었으나 (p=0.054), 폐포-동맥혈 산소분압차$(P(A-a)O_2)$는 pause 유무에 따른 차이가 없었다 ($185.3{\pm}86.5$ mmHg vs. $184.9{\pm}84.9$ mmHg, P=0.766). 평균기도압은 pause를 사용한 경우 $9.7{\pm}4.0\;cmH_2O$로 사용하지 않은 경우의 $8.8{\pm}4.0\;cmH_2O$보다 유의하게 높았다 (p<0.01). Pause를 사용했을 때의 pause pressure와 pause를 사용하지 않을 때의 최고흡기압의 차이는 호흡기계의 저항과 역상관관계를 보였으나 (r=-0.777, p<0.01), pause가 없을 때의 최고흡기압에서 pause를 사용했을 때의 최고흡기압으로의 증가는 호흡기계의 저항과 정상관관계를 보여 (r=0.811, p<0.01), 평균기도압의 차이는 호흡기계의 저항과 유의한 정상관관계를 보였다(r=0.681, p<0.05). 평균기도압의 변화는 $PaCO_2$의 변화와 상관관계를 보이지 않았다. 결 론: Volume control ventilation시 동일한 1:3 의 I:E ratio하에서라도 5%의 inspiratory pause를 사용하는 것이 평균기도압을 더 높게 유지할 수 있으며 폐환기를 호전시킬 수 있는 것으로 사료되었다. 또한 호흡기계의 저항이 증가되어 있을수록 평균기도압의 상승이 많았으나 평균기도압의 상승 정도는 폐환기의 변화와 상관관계를 보이지 않았다. Background : In volume-controlled ventilation, the use of inspiratory pause increases the inspiratory time and thus increases mean airway pressure and improves ventilation. But under the same I : E ratio, the effects of inspiratory pause on mean airway pressure and gas exchange are not certain. Moreover, the effects may be different according to the resistance of respiratory system. So we studied the effects of inspiratory pause on airway pressure and gas exchange under the same I : E ratio in volume-controlled ventilation. Methods: Airway pressure and arterial blood gases were evaluated in 12 patients under volume-controlled mechanical ventilation with and without inspiratory pause time 5%. The I : E ratio of 1 : 3, $FiO_2$, tidal volume, respiratory rate, and PEEP were kept constant. Results: $PaCO_2$ with inspiratory pause was lower than without inspiratory pause ($38.6{\pm}7.4$ mmHg vs. $41.0{\pm}7.7$ mmHg. p<0.01). P(A-a)$O_2$ was not different between ventilation with and without inspiratory pause $185.3{\pm}86.5$ mmHg vs. $184.9{\pm}84.9$ mmHg, p=0.766). Mean airway pressure with inspiratory pause was higher than without inspiratory pause ($9.7{\pm}4.0\;cmH_2O$ vs. $8.8{\pm}4.0\;cmH_2O$, p<0.01). The resistance of respiratory system inversely correlated with the pressure difference between plateau pressure with pause and peak inspiratory pressure without pause (r=-0.777, p<0.l), but positively correlated with the pressure difference between peak inspiratory pressure with pause and peak inspiratory pressure without pause (r=0.811, p<0.01). Thus the amount of increase in mean airway pressure with pause positively correlated with the resistance of respiratory system (r=0.681, p<0.05). However, the change of mean airway pressure did not correlated with the change of $PaCO_2$. Conclusion: In volume-controlled ventilation under the same I : E ratio of 1 : 3, inspiratory pause time of 5% increases mean airway pressure and improves ventilation. Although the higher resistance of respiratory system, the more increased mean airway pressure, the increase in mean airway pressure did not correlated with the change in $PaCO_2$.

임직원 스톡옵션의 행사패턴 및 조기행사에 영향을 미치는 요인에 관한 연구

김현아 ( Hyeon A Kim ),정성창 ( Sung Chang Jung ) 한국재무관리학회 2009 財務管理硏究 Vol.26 No.2