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THE EFFECT OF LACTIC ACID CONCENTRATION AND pH OF LACTIC ACID BUFFER SOLUTIONS ON ENAMEL REMINERALIZATION (완충 용액의 유산 농도와 pH가 법랑질의 재광화에 미치는 영향)

  • Kwon, Jung-Won;Suh, Duk-Gyu;Song, Yun-Jung;Lee, Yun;Lee, Chan-Young
    • Restorative Dentistry and Endodontics
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    • v.33 no.6
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    • pp.507-517
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    • 2008
  • There are considerable in vitro and in vivo evidences for remineralization and demineralization occurring simultaneously 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 (${\times}100$) 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.

EFFECT OF IRRIGATION METHODS ON THE ADHESION OF RESILON/EPIPHANY SEALER AND GUTTA-PERCHA/AH 26 SEALER TO INTRACANAL DENTIN (근관 세척법이 Resilon/Epiphany sealer와 Gutta-percha/AH 26 sealer의 근관 상아질과의 접착에 미치는 영향)

  • Kim, Seo-Kyong;Hwang, Yun-Chan;Hwang, In-Nam;Oh, Won-Mann
    • Restorative Dentistry and Endodontics
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    • v.33 no.2
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    • pp.98-106
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    • 2008
  • The purpose of this study was to evaluate whether intracanal irrigation method could affect the adhesion between intracanal dentin and root canal filling materials (Gutta-percha/AH 26 sealer and Resilon/Epiphany sealer). Thirty extracted human incisor teeth were prepared. Canals were irrigated with three different irrigation methods as a final rinse and obturated with two different canal filling materials (G groups: Gutta-percha/AH 26 sealer, R groups: Resilon/Epiphany sealer) respectively. Group G1, R1-irrigated with 5.25% NaOCl Group G2, R2-irrigated with 5.25% NaOCl, sterile saline Group G3, R3-irrigated with 5.25% NaOCl, 17% EDTA, sterile saline Thirty obturated roots were horizontally sliced and push-out bond strength test was performed in the universal testing machine. After test, the failure patterns of the specimens were observed using Image-analyzing microscope. The results were as follows. 1. Gutta-percha/AH 26 sealer groups had significantly higher push-out bond strength compared with the Resilon/Epiphany sealer groups (p < 0.05). 2. Push-out bond strength was higher when using 17% EDTA followed by sterile saline than using NaOCl as a final irrigation solution in the Resilon/Epiphany sealer groups (p < 0.05). 3. In the failure pattern analysis, there was no cohesive failure in Group G1, G2, and R1. Gutta-percha/AH 26 sealer groups appeared to exhibit predominantly adhesive and mixed failure patterns, whereas Resilon/Epiphany sealer groups exhibited mixed failures with the cohesive failure occurred within the Resilon substrate.

A Study on the Change of Landscape in Bulguksa Temple through a Iconographic Materials in the Period of Japanese Occupation (일제강점기 도상자료를 통한 불국사의 경관변화에 관한 연구)

  • Kim, Kyu-Won;Ahn, Gye-Bog;Sim, Woo-Kyung
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.33 no.1
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    • pp.21-30
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    • 2015
  • Bulguksa Temple, a typical temple of Silla was lost during Japanese Invasion of Korea and there are records of reconstructing in its record, Bulguksa Sajeok. There is no record after that. And reconstructing was stopped due to lack of money and repair works were conducted for two times in Japanese colonial era. First repair work was from 1989 to 1919 and second repair work was conducted from 1922 to 1925. After Liberation, Bulguksa Temple Restoration Committee was established in 1969 and the construction has started since 1970 after excavation investigation to complete in 1973. The shape of south arcade without walls in the main temple of Bulguksa was found in a blue print of Bulguksa in Japanese colonial era in National Archives of Korea now and a picture of Bulguksa in 1902 taken by Sekino Tadashi. It verified the correlation between Gupumyeonji which was discovered in restoration work in 1970s and a legend of Muyoungtap. And a stair from the hall of Paradise to the main temple was introduced as a stair including Pure Land Buddhism doctrine in many literature materials, but a blue print of Bulguksa in Japanese colonial era and reports of excavation investigation in 1970s verified that it was a temporary stair built by Japan and its meaning was given later. This research checked the scenery of Bulguksa Temple before Japanese colonial era and it is intended for basic data to conduct restoration or reconstruction project in the future.

Content and Meaning of Royal Garden Sightseeing Event in Pyoam's 「Hogayugeumwongi」 (표암(豹菴)의 「호가유금원기(扈駕遊禁苑記)」에 나타난 궁원 유람행사의 내용과 의미)

  • Hong, Hyoung-Soon
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.32 no.2
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    • pp.1-11
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    • 2014
  • This study aimed at investigating the content and meaning of royal garden(宮苑) sightseeing event in Pyoam Gang, sehwang's "Hogayugeumwongi" As the research method, descriptive research method was used, which is to consider and interpret the content and meaning in the historical records. Research results are summarized as follows. 1. "Hogayugeumwongi", which recorded the event that the King personally guided and explained the palace to the vassals, is a very precious historical records in Korean landscape gardening cultural history. Such thing is unprecedented in Joseon Dynasty as well as China. 2. The person who recorded this event was famous for shi seo hwa samjeol in the time, and the point that he was Pyoam, who was appreciated as 'the head(總帥) of artistic and literary circles(藝苑)', adds more value to the future generations. 3. The characteristic of this sightseeing event was to praise the vassals' labor, who contributed to the completion of Kyujanggak, to establish King Jongjo's direct rule in the early period of seizure of power, and eojin(御眞) dosa(圖寫), etc., which expressed the King's dignity. Jongjo utilized Geumwon, a forbidden place in the palace, to give a special privilege to the vassals' effort, who took a great part in realizing his political ideal. 4. One of sightseeing lines toward the backyard of Changdeok Palace could be identified. Though the sightseeing lines toward the backyard were not fixed, however this might be the best sightseeing line which Jongjo intentionally chose to enjoy that day's flavor of autumn. 5. The characteristic of this event was informal and somewhat extemporary 'sightseeing'. Therefore, it is considered, that day's event was relatively private and free 'play(遊)', while 'sanghwaeojoyeon(賞花漁釣宴)', which Jongjo gave to the vassals middle after his reign, was a royal 'banquet', which prepared frames, such as event holding time and form, qualification for participation, e.g. flower viewing, fishing, writing poems, etc. This research has a significance that it considered the content and meaning in historical records including the front and the rear context that "Hogayugeumwongi" was written through the consideration of related historical materials. "Hogayugeumwongi" can be utilized as a material for storytelling with regard to royal garden sightseeing in future as a valuable cultural content, also, follow-up study on this is necessary.

Spatio-temporal Distributions of Phytoplankton Community in the Coastal Waters of Gogunsan Islands(CoWGIs), West Sea of Korea (고군산군도 해역의 식물플랑크톤 군집의 시·공간적 분포 및 출현 환경특성)

  • Yoon, Yang Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.3
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    • pp.2287-2300
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    • 2015
  • This study examined the spatio-temporal distributions of the phytoplankton community in the coastal waters of Gogunsan Islands (CoWGIs), West Sea of Korea, from January to September 2011. A total of 104 species of phytoplankton belonging to 56 genera were identified. This was low compared to the surrounding seas of the West Sea. In particular, diatoms and dinoflagellates comprised 60.5% and 34.6%, respectively, and it was most diverse in autumn. The standing crops fluctuated from $9.6{\times}10^4cells/L$ to $1.0{\times}10^7cells/L$. This was high in winter and summer and low in spring and autumn. The seasonal dominant species were Skeletonema costatum-like species, Thalassiosira nordenskioeldii, Dactyliosolen fragillisimus, and Chaetoceros debilis in winter, Guinardia delicatula in spring, Eucampia zodiacus, Cylindrotheca closterium, Ch. debilis, and Ch. curvisetus in summer, and S. costatum-like species, Ch. debilis, Ch. curvisetus, G. delicatula, and Leptocylindrus danicus in autumn. The total number of autochthonous and tychopelagic species was 39 species. This showed a 1/3 (33.3%) decrease compared to the 1980's. The chlorophyll a concentration fluctuated from $3.82{\mu}g/L$ in autumn to $13.36{\mu}g/L$ in summer. The bio-oceanographic characteristics of the CoWGIs based on principle component analysis (PCA) showed that it was dominated by the Saemangeum water mass in the high temperature season and by the Geum River water mass in the low temperature season. In other words, there has been a conversion to a closed inner bay followed by the dramatic progress of eutrophication, even in the CoWGIs after completion of the Saemangeum embankment.

A Control Method for designing Object Interactions in 3D Game (3차원 게임에서 객체들의 상호 작용을 디자인하기 위한 제어 기법)

  • 김기현;김상욱
    • Journal of KIISE:Computing Practices and Letters
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    • v.9 no.3
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    • pp.322-331
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    • 2003
  • As the complexity of a 3D game is increased by various factors of the game scenario, it has a problem for controlling the interrelation of the game objects. Therefore, a game system has a necessity of the coordination of the responses of the game objects. Also, it is necessary to control the behaviors of animations of the game objects in terms of the game scenario. To produce realistic game simulations, a system has to include a structure for designing the interactions among the game objects. This paper presents a method that designs the dynamic control mechanism for the interaction of the game objects in the game scenario. For the method, we suggest a game agent system as a framework that is based on intelligent agents who can make decisions using specific rules. Game agent systems are used in order to manage environment data, to simulate the game objects, to control interactions among game objects, and to support visual authoring interface that ran define a various interrelations of the game objects. These techniques can process the autonomy level of the game objects and the associated collision avoidance method, etc. Also, it is possible to make the coherent decision-making ability of the game objects about a change of the scene. In this paper, the rule-based behavior control was designed to guide the simulation of the game objects. The rules are pre-defined by the user using visual interface for designing their interaction. The Agent State Decision Network, which is composed of the visual elements, is able to pass the information and infers the current state of the game objects. All of such methods can monitor and check a variation of motion state between game objects in real time. Finally, we present a validation of the control method together with a simple case-study example. In this paper, we design and implement the supervised classification systems for high resolution satellite images. The systems support various interfaces and statistical data of training samples so that we can select the most effective training data. In addition, the efficient extension of new classification algorithms and satellite image formats are applied easily through the modularized systems. The classifiers are considered the characteristics of spectral bands from the selected training data. They provide various supervised classification algorithms which include Parallelepiped, Minimum distance, Mahalanobis distance, Maximum likelihood and Fuzzy theory. We used IKONOS images for the input and verified the systems for the classification of high resolution satellite images.

The Prediction of Shelf-life of Pickle Processed from Maengjong bambo (맹종죽순 장아찌의 유통기한 설정)

  • Kim, Dong-Chung;Cho, Eun-Hye;In, Man-Jin;Oh, Chul-Hwan;Hong, Ki-Woon;Kwon, Sang-Chul;Chae, Hee-Jeong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.6
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    • pp.2641-2647
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    • 2012
  • Quality and sensory characteristics such as microbial count, pH, acidity, flavor, taste, color and overall acceptance of bamboo shoot pickle cured with red pepper paste and bamboo shoot pickle cured with soy sauce paste made of Maengjong bamboo shoots were investigated during a long-term storage at different temperature (at $25^{\circ}C$, $35^{\circ}C$ and $45^{\circ}C$). Microbial contamination was not observed, and water content did not showed significant change in all samples of both pickles during the whole storage period of 30 days, regardless of storage temperature. At $25^{\circ}C$, all sensory characteristics of bamboo shoot-red pepper paste pickle did not show a significant change for 30 d. However, at $35^{\circ}C$ and $45^{\circ}C$, the flavor, taste and color of bamboo shoot-red pepper paste pickle did not change remarkably, but the overall acceptance significantly changed from the beginning of storage. Bamboo shoot-soy sauce pickle did not give a significant change in flavor, taste and overall acceptance at $25^{\circ}C$, $35^{\circ}C$ and $45^{\circ}C$. However a remarkable change in color started to be shown at 25 d in case of storage at $45^{\circ}C$. Overall acceptance and color were selected as indicating parameters for the shelf-life estimation of bamboo shoot-red pepper paste pickle and bamboo shoot-soy sauce pickle, respectively. Based on room temperature storage and delivery at $20^{\circ}C$, the shelf-life of bamboo shoot-red pepper paste pickle and bamboo shoot-soy sauce pickle were determined as 308 d (about 10 month) and 447 d (about 14 month), respectively.

Correlation analysis of sodium-related knowledge, dietary behavior, attitudes towards a low-salt diet and meal attitude guidance for elementary school teachers in Jeonbuk area (전북지역 초등학교 교사의 나트륨에 대한 지식, 나트륨섭취 식행동, 저염식 태도 및 식생활지도와의 관계 연구)

  • Moon, Hyun Ok;Rho, Jeong Ok
    • Journal of Nutrition and Health
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    • v.50 no.2
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    • pp.180-191
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    • 2017
  • Purpose: The purpose of the study was to identify teacher's knowledge about sodium, dietary behaviors related to sodium, attitudes towards a low-salt diet, and meal attitude guidance as well as examine the relationship between these variables. Methods: The participants were 351 teachers at an elementary school in the Jeonbuk area. The data were analyzed using ANOVA, Duncan test, and Pearson correlation coefficients with SPSS v. 20.0. Results: The score for teachers' knowledge about sodium was 12.92 points of a possible 16, the score for dietary behavior related to sodium was 46.85 points of a possible 70, and the score for attitude towards a low-salt diet was 33.63 points of a possible 50. Their score for meal attitude guidance was 59.95 points of a possible 80. The knowledge showed significant differences by hypertension drug (p < 0.05) and stress level (p < 0.05). The dietary behavior of sodium use showed significant differences by gender (p < 0.01), work experience (p < 0.05), BMI (p < 0.01), drinking (p < 0.05), concern about health (p < 0.05), and stress level (p < 0.05). The attitude towards a low-salt diet showed significant differences by gender (p < 0.05), marital status (p < 0.05), work experience (p < 0.05), drinking (p < 0.05), concern about health (p < 0.001), and stress level (p < 0.05). Meal attitude guidance showed a significant difference by marital status (p < 0.001), age (p < 0.001), work experience (p < 0.001), drinking (p < 0.01), regularity of health checkup (p < 0.001), concern about health (p < 0.001), and stress level (p < 0.05). There was a low positive correlation between knowledge about sodium and dietary behavior related to sodium as well as between dietary behavior related to sodium and attitudes towards a low-salt diet. Attitudes towards a low-salt diet showed a positive correlation with meal attitude guidance. Conclusion: Therefore, it is necessary to consider educational programs on increasing knowledge and attitudes towards a low-salt diet in teachers for improvement of meal attitude guidance activities for students.

Evaluation of the sodium intake reduction plan for a local government and evidence-based reestablishment of objectives: Case of the Seoul Metropolitan Government (지자체의 나트륨 섭취 감소 계획 평가 및 근거 기반 목표 재설정 : 서울시 사례를 중심으로)

  • Lim, A-Hyun;Hwang, Ji-Yun;Kim, Kirang
    • Journal of Nutrition and Health
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    • v.50 no.6
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    • pp.664-678
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    • 2017
  • Purpose: To identify the effectiveness of policy evaluation, consistent monitoring is necessary. This study aimed to carry out mid-term evaluation of objectives and programs related to comprehensive plans for sodium intake reduction by 2020 for Seoul city and then reestablish the objectives of the sodium intake reduction plans. Methods: Literature reviews, data analysis, and reviews of expert focus-groups were performed to evaluate objectives, to develop a new goal, and to identify the priority subjects of the sodium intake reduction programs. In order to examine target populations for the programs, awareness and behaviors related to sodium intakes among Seoul citizens were examined by sex, age, and income level using the 2008~2013 Korea National Health and Nutrition Examination Survey data. Results: Current objectives of the sodium intake reduction plan by 2020 for Seoul city were not appropriate, so objectives were reset to 3,600 mg of sodium intake by 2020 among Seoul citizens with 2% reduction per year. Although sodium intake showed a decreasing trend by year, it was still high, especially in men. The sodium intake reduction programs currently in progress have not been assessed at multiple levels across multiple sectors and have only been assessed fragmentarily. For dietary behavior related to sodium intakes by sex, age, and income level, sodium intake was higher in the group with less than 100 g of fruit intake compared to the group with 100 g or more. Subjects aged 30~59 years and the low household income group showed relatively higher sodium intakes. Based on the data analysis and the expert review, the priority subject of the sodium intake reduction programs was determined to be adult men. In terms of a program strategy for sodium intake reduction, multi-level and setting approaches, including work sites, home, and restaurants, were suggested to reduce sodium intakes of the target subject. Conclusion: The suggested objectives should be consistently monitored by data analysis, and the determined programs need to be phased in over 5 years.

Energy expenditure of physical activity in Korean adults and assessment of accelerometer accuracy by gender (성인의 13가지 신체활동의 에너지 소비량 및 가속도계 정확성의 남녀비교)

  • Choi, Yeon-jung;Ju, Mun-jeong;Park, Jung-hye;Park, Jong-hoon;Kim, Eun-kyung
    • Journal of Nutrition and Health
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    • v.50 no.6
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    • pp.552-564
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    • 2017
  • Purpose: The purpose of this study was to measure energy expenditure (EE) the metabolic equivalents (METs) of 13 common physical activities by using a portable telemetry gas exchange system ($K4b^2$) and to assess the accuracy of the accelerometer (Actigraph $GT3X^+$) by gender in Korean adults. Methods: A total of 109 adults (54 males, 55 females) with normal BMI (body mass index) participated in this study. EE and METs of 13 selected activities were simultaneously measured by the $K4b^2$ portable indirect calorimeter and predicted by the $GT3X^+$ Actigraph accelerometer. The accuracy of the accelerometer was assessed by comparing the predicted with the measured EE and METs. Results: EE (kcal/kg/hr) and METs of treadmill walking (3.2 km/h, 4.8 km/h and 5.6 km/h) and running (6.4 km/h) were significantly higher in female than in male participants (p < 0.05). On the other hand, the accelerometer significantly underestimated the EE and METs for all activities except descending stairs, moderate walking, and fast walking in males as well as descending stairs in females. Low intensity activities had the highest rate of accurate classifications (88.3% in males and 91.3% females), whereas vigorous intensity activities had the lowest rate of accurate classifications (43.6% in males and 27.7% in females). Across all activities, the rate of accurate classification was significantly higher in males than in females (75.2% and 58.3% respectively, p < 0.01). Error between the accelerometer and $K4b^2$ was smaller in males than in females, and EE and METs were more accurately estimated during treadmill activities than other activities in both males and females. Conclusion: The accelerometer underestimated EE and METs across various activities in Korean adults. In addition, there appears to be a gender difference in the rate of accurate accelerometer classification of activities according to intensity. Our results indicate the need to develop new accelerometer equations for this population, and gender differences should be considered.