완충 용액의 유산 농도와 pH가 법랑질의 재광화에 미치는 영향

권중원,서덕규,송윤정,이윤,이찬영 大韓齒科保存學會 2008 Restorative Dentistry & Endodontics Vol.33 No.6

There are considerable in vitro and in vivo evidences for remineralization and demineralization occurring Simul-taneously in incipient enamel caries. In order to "heal" the incipient dental caries, many experiments have been carried out to determine the optimal conditions for remineralization. It was shown that remineralization is affected by different pH, lactic acid concentrations, chemical composition of the enamel, fluoride concentrations, etc. Eighty specimens from sound permanent teeth without demineralization or cracks, 0.15 mm in thickness, were immersed in lactic acid buffered demineralization solutions for 3 days. Dental caries with a surface zone and subsurface lesion were artificially produced. Groups of 10 specimens were immersed for 10 or 12 days in lactic acid buffered remineralization solutions consisting of pH 4.3 or pH 6.0, and 100, 50, 25, or 10 mM lactic acid. After demineralization and remineralization, images were taken by polarizing microscopy (×100) and micro-computed tomography. The results were obtained by observing images of the specimens and the density of the caries lesions was determined. 1.As the lactic acid concentration of the remineralization solutions with pH 4.3 was higher, the surface zone of the carious enamel increased and an isotropic zone of the subsurface lesion was found. However, the total decalcification depth increased at the same time 2.In the remineralization solutions with pH 6.0, only the surface zone increased slightly but there was no significant change in the total decalcification depth and subsurface zone. In the lactic acid buffer solutions with the lower pH and higher lactic acid concentration, there were dynamic changes at the deep area of the dental carious lesion. 본 연구의 목적은 유산 완충 용액의 pH및 유산 농도 변화가 법랑질에서 인공 우식 병소의 재광화 양상에 미치는 영향을 평가하기 위함이다. 유산 완충 용액을 이용하여 법랑질을 탈회시키고, 유산의 농도가 100, 50, 25, 10 mM이고 pH가 4.3인 네 가지 재광화 용액 (Group 1, 2, 3, 4)에 10일, pH 6.0인 네 가지 재광화 용액 (Group 5, 6, 7, 8)에 12일간 처리한 후 무기질의 양적 변화를 편광 현미경에서 얻은 상에서의 탈회 깊이의 변화, 우식 표면층 깊이의 변화로 측정하였다. 또한 micro-computed tomography (micro-CT)를 이용하여 탈회 후와 재광화 후를 촬영하여 얻은 상으로부터 lesion부위의 density를 비교하였다. 1. pH 4.3에서 유산 농도가 증가할수록 우식 표면층의 증가와 표층하 탈회부 중 심층부의 isotropic zone등의 재광화 현상을 보이나, 전체 탈회 깊이 역시 증가하였다. 2. pH 6.0에서 우식 표면층에 국한된 재광화 현상을 보이고, 전체 탈회 깊이는 변화가 없었다. 이상의 실험 결과로 미루어 포화도가 일정한 유산 완충 용액으로 재광화 유도시 pH가 낮고 유산의 농도가 높을수록 표면으로부터 심층부 동역학적 변화에 더 영향을 주었으며, micro-CT를 이용한 우식 병소부위의 density 확인을 통해 무기질의 침착과 방출 현상을 객관적으로 평가할 수 있었다.

21세기 대구 · 경북의 성장 동력으로서 『문화자본』의 의미

권찬태,권기정,김진수,이영기 慶北大學校出版部 2005 經商論集 Vol.32 No.2

본 연구에서는 문화자본의 의미를 바탕으로 대구 · 경북이 본래 가지고 있지만, 활용하지 못하고 있던 문화자본을 대구 · 경북 지역의 성장동력 산업으로 이끌기 위한 전체적인 방향을 제시하고자 하였다. 첫째, 대구 · 경북은 문화의 21세기에서 창조적이고 차별화된 문화자본을 축적하기 위해 지역 내 숨겨진 자원을 발굴하고, 개발해야 한다. 둘째, 사회 · 문화 주동적 성향을 토대로 창의적이고 미래지향적인 문화상품을 개발해 나가야 하고, 세계 속에 대구 · 경북을 알릴 수 있는 대표 브랜드 상품 개발에 주력해야 한다. 셋째, 풍부한 문화유산, 자연환경 등의 유 · 무형의 자원을 최대한 활용하여야 한다. 본 연구에서는 이러한 세 가지 방안의 실천을 위한 행정기관, 기업, 언론 및 교육기관에 따른 방법 또한 제시하였다. 먼저, 지역정부는 문화인프라 구축의 중요성을 인식해야한다. 다음으로, 기업은 문화자본 축적을 비용으로 생각하기보다는 투자로 생각할 수 있는 인식의 전환이 필요하다. 마지막으로, 언론 및 교육기관에서는 선진문화지역으로 도약하기 위한 지역 주민들의 자긍심과 인식이 확대될 수 있도록 도와주어야한다. This paper suggested that the role of cultural capital to be economic growth engine in Daegu and Kyungpook region. Daegu and Kyungpook's role is as followed ; The first, Daegu and Kyungpook should develop and unearth hidden cultural resources, and the second, should develop creative cultural goods based on social and cultural propensity, the third should use the tangible and intangible resources such as cultural inheritance and nature. Besides this, this paper also suggested the roles of local government, local business, local press and local educational institution in Dageu and Kyungpook region. At first, local government should recognize the importance of cultural infrasturcture, the local business needs the concept of cultural capital, and the local press and educational institution should help local citizens have the pride of local culture.

폐결핵 환자 혈청에서 수용성 Interleukin 2 수용체 및 Adenosine Deaminase 활성도에 관한 연구

고정희,박성규,백상현,박찬권,박병수,안진영,최우석,박정규 충남대학교 의과대학 지역사회의학연구소 1993 충남의대잡지 Vol.20 No.1

Interleukin-2 (IL-2) induces T cell proliferation in an autocrine manner and provides a means by which antigen triggered T cells can be clonally expanded in vitro. During the following activation, the activity of IL-2 is mediated by specific high affinity IL-2 binding membrane receptors which are expressed shortly after activation. In this process, a 42 KD-fragment (soluble IL-2R) is continuously cleaved off and circulates as a soluble marker of T lymphocyte activation. Elevated level of soluble IL-2R has been identified in the serum of patients with malignant autoimmune and allergic disorders, systemic parasitic infection, undergoing graft versus host disease, acute or chronic lymphocytic leukemia and HIV-infection. ADA (adenosine deaminase) completes the process of differentiation of T cell and is essential for progression of T cell maturation. Therefore level of ADA is to correlated with magnitude of T cell immune response. The fact that expression of sIL-2R and ADA activity increases in peripheral blood T-lymphocytes of patients with active pulmonary tuberculosis suggests that T cell activation might have a major role in the pathogenesis of pulmonary tuberculosis. In order to evaluate the T cell immune response in pulmonary tuberculosis, we measured the serum concentration of sIL-2R and ADA activity in 17 patients with current pulmonary tuberculosis, 10 chronic inactive pulmonary tuberculosis, 10 as normal controls. (1) Current pulmonary tuberculosis had significantly higher levels of sIL-2R (237.24±95.47)when compared with those of inactive tuberculosis (78.6±11.06). and the control (68.17±15.4) group. (2) ADA activity in current pulmonary tuberculosis was significantly increased (34.41±20.63) when compared with those of inactive tuberculosis (24.7±14.36) and control (17.65± 5.94) group. (3) There was good correlation between sIL-2R concentration and ADA activity in serum in current pulmonary tuberculosis group. (4) sIL-2R concentration and ADA activity was decreased significantly 6 months after anti-tuberculosis drug medication. In conclusion, sIL-2R concentration and ADA activity in serum in current pulmonary tuberculosis group was increased when compared with those of inactive pulmonary tuberculosis and the control group. By the way, T cell mediated immune response was enhanced in current pulmonary tuberculosis, but in inactive chronic pulmonary tuberculosis who had treated by antituberculosis drug medication, the concentration of sIL-2R and ADA activity was nearly normal.

리벳 구멍을 가진 알루미늄 박판구조의 피로손상 탐지를 위한 음향방출의 활용

김정찬,권오양,김성진 한국비파괴검사학회 2003 한국비파괴검사학회지 Vol.23 No.3

항공기 구조를 모사하여 일련의 리벳 구멍을 갖는 AA2024-T3 박판 구조를 대상으로 피로하중에 의한단균열(short crack)의 발생시점과 성장거동을 음향방출(AE)을 위주로 한 측정으로 평가하였다.AE 위치표정에 의해 단균열의 좌표를 정확하게 결정하였으며, 이동식 현미경으로 균열의 크기를 측정하였다. 누적 AE 발생수 곡선은 단균열의 발생과 성장에 따라 일정한 간격을 두고 급격히 증가하는 양상을 보임으로써 여러 차례의 계단식 곡선을 형성하였다. AE 위치표정에서는 리벳구멍을 중심으로 파괴역학에 근거한 관심영역(ROI)을 설정하였으며, 웨이블릿변환 잡음제거 방법을 사용하여 위치표정의 정확도를 향상할 수 있었다. 실제로 탐지된 신호의 대부분이 단균열의 발생 및 성장과 관계없는 외부 잡음신호로 나타났으며, ROI 내에서 발생한 AE 발생원의 위치도 구조의 기하학적 특징이나 신호대잡음비의 영향에 의해 왜곡될 수 있음을 알 수 있었다. The initiation and growth of short fatigue cracks in the simulated aircraft structure with a series of rivet holes was detected by acoustic emission (AE). The location and the size of short cracks were determined by AE source location techniques and the measurement with traveling microscope. AE events increased intermittently with the initiation and growth of short cracks to form a stepwise increment curve of cumulative AE events. For the precise determination of AE source locations, a region-of-interest(ROI) was set around the rivet holes based on the plastic zone size in fracture mechanics. Since the signal-to-noise(SNR) was very low at this early stage of fatigue cracks, the accuracy of source location was also enhanced by the wavelet transform de-noising. In practice, the majority of AE signals detected within the ROI appeared to be noise from various origins. The results showed that the effect of structural geometry and SNR should be closely taken into consideration for the accurate evaluation of fatigue damage in the structure.

철근콘크리트 전단벽체의 형식에 따른 구조성능 평가

全燦穆,權重培,申鍾學,河基柱 慶一大學校 1996 論文集 Vol.13 No.2

In this study, nine reinforced concrete infilled frames involved bare frames were tested during vertical and cyclic loads simultaneously. This test programs were carried to investigate the horizontal strength and the crack propagation in variance with hoop reinforcement ratio. All specimens were modeling in one-third scale size. In this experimental program structural performance of reinforced concrete shear wall were focus at connection types. Based on the test results, the following conclusions are made. (1) In fully rigid frame, increasing the ratio of hoop bar 2∼3 times on the basis of its ratio of in column(p??=0.196%). The horizontal strength of specimen did not varied, but the increased ductility of specimens were showed greatly at the final failure. (2) In the boundary column menber of reinforced concrete shear wall, increasing the ratio of hoop bar in two or three times, in the fully babel type, the shear and horizontal strength of specimens were increased 1.1-1.2 times than that of fully rigid frame. And infilled shear wall specimen were increased 1.17-1.27 times than that. (3) Fully rigid babel type shear wall specimens were increased 5.7∼8.0 times, and infilled shear wall specimens were increased about 4.0∼5.6 times in comparision with the full rigid frame.

윈도우 환경에서 음성인식을 이용한 인터넷 검색기 구현

임중혁,원호준,백인찬,권영헌,이건상 한양대학교 이학기술연구소 1999 이학기술연구지 Vol.1 No.-

본논문에서는 Window 상에서 웹브라우저 검색어로 영문 알파벳을 인식하도록 하였다. 음성의 특징 벡터로는 10차원의 LPC, cepstrum, LSF(Line Spectrum Frequency) 계수와, 규격화된 필터뱅크 에너지를 사용하였으며 인식 알고리즘으로는 MSVQ 모델을 사용하였다. 인식 대상 어휘는 26개의 알파벳을 사용하였으며 실험결과 필터뱅크 에너지를 사용한 인식결과가 가장 우수한 것으로 나타났다. This paper represents the speech recognizer of English alphabet for the internet explorer in Windows. We use 10-dimensional LPC, cepstrum, LSF coefficients and normalized filter bank energies as the speech feature vectors and MSVQ model as the recognition algorithm. As the results the recognizer using the normalized filter bank energies shows the better performance than that using the other feature vectors.

저주파수 및 저입력전압용 박막형 다중접합 열전변환기

황찬순,이형주,김진섭,이정희,박세일,권성원 한국센서학회 2002 센서학회지 Vol.11 No.3

저주파수의 저전압용 크로멜-알루멜 다중접합 열전변환기를 개발하고자 NiCr 히터의 두께를400 nm, 600 nm 및 800 nm로 변화시켰다. 40 Hz∼10 kHz의 직류 역방향 주파수 범위로 0.5 V의 교류 실효전압을 열전변환기에 인가시켰을 때 히터의 두께가 400 nm인 열전변환기가 ±0.51∼±1.69 ppm 범위의 열전효과에 의한 교류-직류 전압 변환오차를 나타내었고, 열전효과 및 주파수에 의한 교류-직류 변환오차는 40 Hz∼l MHz의 주파수 범위에서 ±40∼±115 ppm 범위를 나타내어, 저주파수의 저전압용으로 사용할 수 있었다. NiCr-heaters with three different thicknesses ranging from 400 nm to 800 nm were fabricated and their characteristics were compared for the purpose of developing a chromel-alumel multijunction thermal converter for low input voltage with low frequency. The thermoelectric effect-induced AC-DC voltage transfer difference of the thermal converter with a built-in NiCr-heater of 400 nm-thickness was ±0.51∼±1.69 ppm in the DC reversing frequency of 40 Hz∼10 kHz with appling 0.5 V_rms and the difference was increased to ±40∼±115 ppm in the frequency of 40 Hz~l MHz, when both thermoelectric effects and frequency effects were considered, showing the thermal converter would be suitable for the low input voltage application with low frequency.

항공기구조 모사 알루미늄 박판에서의 피로균열 탐지 및 표면초음파를 이용한 균열크기 측정

김정찬,권오양 한국비파괴검사학회 2004 학술대회 논문집 Vol.- No.-

Since the fatigue damage usually occurs around the rivet holes in aircraft structures, the detection and sizing of short fatigue cracks emanating from rivet holes is extremely important. The initiation of fatigue cracks in a simulated aircraft structures with a series of rivet holes was detected by acoustic emission(AE), and the crack length was determined by the surface acoustic wave(SAW) technique. AE events increased intermittently with the initiation and growth of short cracks to form a stepwise incremental curve of cumulative AE events. with the SAW technique employed, the crack sizing in the range of 1∼8 mm long was possible but it was impossible in the range shorter than 1 mm.

正氣天香湯 및 加味正氣天香湯의 效能에 대한 實驗的 硏究

朴贊基,權貞南,金榮均 한국한의학연구원 1997 한국한의학연구원논문집 Vol.3 No.1

Effects of Jeongkicheonhyangtang and Kamijeongkicheonhyangtang have been experimentally studies. The results have been obtained as follows: 1. It is proved that analgecic effect on sample I group and sample II group are clearly decreased than control group. Thus, the statistically significant decrease is p<0.005. 2. It is proved that anti-inflammatory effect on sample I group and sample II group are decreased compare to control group. Thus, the statistically significant decrease of sample I group is p<0.05 in 30 and 60-minute, p<0.01 in 90-minute, and p<0.005 in 12 and p<0.005 in 90, 120 and 180-minute. 3. It is proved that appearance of gastric ucler is decreased compare to the control group and the statistically significant decrease is p<0.05. 4. It is proved that plasma epinephrine contents of sample I and II group are clearly decreased compare to the Control Group and the statistically significant decrease is p<0.005 5. It is proved that plasma norepinephrine contents of sample I group is drastically decreased compare to the control group and the statistically significant decrease is p<0.005. 6. It is proved that plasma dopamine contents of sample I and II group are decreased than the control group and statistically significant decrease of the sample I group is p<0.005, and those of the sample II group is p<0.05. As the above mentioned results of experiment, it is believed that Jeongkichenhyang and Kamijeongkicheonhyang have effect for stress.

스포츠 미디어의 윤리성에 대한 담론

김동제,권창기,정찬수 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.4

This research discussed and diagnosed the current ethics of sports media, and indicated a need to report sporting events objectively and evaluated them to ensure more useful and interesting articles and improve sports media. It likewise addressed a need to educate sports reporters who can produce such finest sports articles, and how to secure them. To ensure the ethics of sports media, the research discussed the following matters. They are the conclusion of the research and future direction of sports media. First, a proper understanding of sports media is needed, Likewise, sports media can form public opinions objectively, Thus, sports media play an important role for games and players alike. Second, reporting guidelines of sports media must be established, and education should be offered to foster quality sports reporters and corresponding educational programs should also be secured, Articles, which are written by reporters who are not well-experienced in sports and do not know rules of games well, focus on featuring intriguing and fun-oriented titles, but they do not properly convey details of games and their comments. Third, Sports Media Ethics Committee (tentative name) should be established to systemize the code of ethics of sports media.