• Archives of Pharmacal Research
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• 제23권5호
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• pp.507-512
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• 2000

This study set out to improve the physical and pharmaceutical characteristics of the present formulation using an appropriate experimental design. The work described here concerns the formulation of the dispersible tablet applying direct compression method containing roxithromycin in the form of coated granules. In this study $2^3$ factorial design was used as screening test model and Central Composite Design (CCC) associated with response surface methodology was used as optimization study model to develop and to optimize the proper formulation of roxithromycin dispersible tablet. The three independent variables investigated were functional excipients like binder (X1), disintegrant (X2) and lubricant (X3). The effects of these variables were investigated on the following responses: hardness (Y1), friability (Y2) and disintegration time (Y3) of tablet. Three replicates at the center levels of the each design were used to independently calculate the experimental error and to detect any curvature in the response surface. This enabled the best formulations to be selected objectively. The effect order of each term to all response variable was X3> X2> Xl> X1＊X2> X2＊X2> X2＊X3> X3＊X3> Xl＊X3> Xl＊Xl and model equations on each response variables were generated. Optimized compositions of formula were accordingly computed using those model equations and confirmed by following demonstration study. As a result, this study has demonstrated the efficiency and effectiveness of using a systematic formulation optimization process to develop the tablet formulation of roxithromycin dispersible tablet with limited experiment.

• Ocean Systems Engineering
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• 제7권2호
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• pp.143-155
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• 2017

For complex flexible structures such as nets, the determination of drag forces and its deformation is a challenging task. The accurate prediction of loads on cages is one of the key steps in designing fish farm facilities. The basic physics with a simple cage, can be addressed by the use of experimental studies. However, to design more complex cage system for various environmental conditions, a reliable numerical simulation tool is essential. In this work, the current load on a cage is calculated using a Morison-force model applied at instantaneous positions of equivalent-net modeling. Variations of solidity ratio ($S_n$) of the net and current speed are considered. An equivalent array of cylinders is built to represent the physical netting. Based on the systematic comparisons between the published experimental data for Raschel nets and the current numerical simulations, carried out using the commercial software OrcaFlex, a new formulation for $C_d$ values, used in the equivalent-net model, is presented. The similar approach can also be applied to other netting materials following the same procedure. In case of high solidity ratio and current speed, the hybrid model defines $C_d$ as a function of Re (Reynolds number) and $S_n$ to better represent the corresponding weak diffraction effects. Otherwise, the conventional $C_d$ values depending only on Re can be used with including shielding effects for downstream elements. This new methodology significantly improves the agreement between numerical and experimental data.

• 한국해안·해양공학회논문집
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• 제27권6호
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• pp.443-451
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• 2015

유수실을 두 개 가지는 유공케이슨에 작용하는 파력 산정식은 아직까지 없다. 이 연구에서는 이러한 이중유수실 케이슨 모형에 작용하는 파력을 측정한 수리실험 자료 분석 결과를 제시하였다. 실험결과로부터 세 가지 연직벽체에 작용하는 파력의 첨두값에 연관된 다섯 가지 파의 위상에 따른 파력의 변화 양상을 명확하게 규명할 수 있었으며, 이로부터 Takahashi and Shimosako (1994)와 유사한 형태의 이중유수실 파력보정계수를 산정하였다. 이 결과는 향후 추가 실험 및 현장 실무에의 적용을 통해 검증될 필요가 있다.

• Steel and Composite Structures
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• 제21권6호
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• pp.1227-1250
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• 2016

Most of the research work has been conducted on K-joints under static loading. Very limited information is available in consideration of fatigue strength of K-joints with concrete-filled chord. This paper aims to describe experimental and numerical investigations on stress concentration factors (SCFs) of concrete-filled circular chord and square braces K-joints under balanced axial loading. Experiment was conducted to study the hot spot stress distribution along the intersection of chord and braces in the two specimens with compacting concrete filled in the chord. The test results of stress distribution curves of two specimens were reported. SCFs of concrete-filled circular chord and square braces K-joints were lower than those of corresponding hollow circular chord and square brace K-joints. The corresponding finite element analysis was also conducted to simulate stress distribution along the brace and chord intersection region of joints. It was achieved that experimental and finite element analysis results had good agreement. Therefore, an extensive parametric study was carried out by using the calibrated finite element model to evaluate the effects of main geometric parameters and concrete strength on the behavior of concrete-filled circular chord and square braces K-joints under balanced axial loading. The SCFs at the hot spot locations obtained from ABAQUS were compared with those calculated by using design formula given in the CIDECT for hollow SHS-SHS K-joints. CIDECT Design Guide was generally quite conservative for predicting SCFs of braces and was dangerous for predicting SCFs of chord in concrete-filled circular chord and square braces K-joints. Finally SCF formulae were proposed for circular chord and square braces K-joints with concrete-filled in the chord under balanced axial loading. It is shown that the SCFs calculated from the proposed design equation are generally in agreement with the values derived from finite element analysis, which were proved to be reliable and accurate.

• 한국지반신소재학회논문집
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• 제22권4호
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• pp.27-34
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• 2023

본 연구에서는 말뚝에 작용하는 구속압과 지반의 세립분 함유율을 고려한 말뚝 인발실험을 실시하였다. 그리고 실험 결과를 이용하여 말뚝의 인발저항에 미치는 지중 구속압의 영향을 분석하여 인발저항정수를 고찰하였다. 인발실험 결과, 모형지반의 세립분 함유율과 구속압의 크기에 관계없이 약 7mm~9mm의 인발변위에서 최대인발저항력이 발생되었다. 말뚝의 최대인발저항력은 모형지반의 세립분 함유율이 증가할수록 감소하였고, 이러한 경향은 구속압이 클수록 현격하게 나타났다. 말뚝인발실험 결과의 신뢰성을 검토하기 위해 인발저항력을 이론식으로 산정해 실험결과와 비교한 결과, 모든 구속압 조건에서 세립분 함유율 증가에 따라 실험값과 이론값 모두 동일하게 인발저항력이 감소하는 경향을 보였다. 인발저항정수에 대한 분석 결과, 말뚝과 지반의 경계에서 발생하는 인발저항력에 있어서 주변 지반의 세립분 함유율이 증가할수록 경계면 마찰각보다 부착력의 영향이 커지는 것을 확인하였다.

• 대한한의학방제학회지
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• 제26권1호
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• pp.13-26
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• 2018

Objectives : This study was carried out to enhance the activity of Iksuyoungjingo, which has the tonify Qi, nourish Yin effect of oriental medicine, and to study the effect of the prescriptions on the immunological activities. Methods : Immunosuppression was induced by methotrexate (MTX) 2 mg / kg, the experimental group was divided into IYGgami-I, IYGgami-I-F, IYGgami-II and IYGgami-II-F groups. Each prescription was administered with drinking water for 20 days, and body weight was measured every 5 days during this period. Leukocyte, $TNF-{\alpha}$, IL-2, IL-6, IgE, spleen weight and body weight were measured Results : In the changes of $TNF-{\alpha}$, IL-2 and IL-6 as pro-inflammatory elements, all of the experimental groups showed a significant increase compared to the control group. In the IgE changes, the IYGgami-I-F, IYGgami-II and IYGgami-II-F groups showed a significant decrease compared to the control group. In the changes of spleen weight, the IYGgami-II-F group showed a significant increase compared to the control group. In the changes of WBC and lymphocytes, the IYGgami-I-F group showed a significant increase compared to the control group. Conclusions : From the above results, it can be observed that the efficacy against immunity is exerted in all of the preparations, and it was confirmed that the efficacy was maintained constant even when utilizing the Rehmannia glutinosa Residue and Poria cocos Bark, and that a more beneficial effect can be exerted in the effectiveness when the fermentation is carried out.

• 동의생리병리학회지
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• 제32권4호
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• pp.255-260
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• 2018

Chung-Sang (CS) is an experimental herbal remedy that is formulated to treat respiratory diseases implicated by inflammation. The herbs comprised of CS are frequently prescribed for treating various inflammatory symptoms: Menthae haplocalycis Herba, Magnoliae Flosis, Xanthii Fructus, Herba Asari, and Caryphylli Flos. Here, we prepared the extract of CS with boiling water (wCS) or with 50 % ethanol (eCS) and examined whether the two different extracts of CS exhibit a toxicity to cultured cells and mice. RAW 264.7 cells were treated with wCS or eCS, and the cytotoxicity of these extracts to RAW 264.7 cells was determined by an MTT assay. Although the production of intracellular reactive oxygen species that are detrimental to the cells was not increased by the extracts, the cytotoxicity to the cells was evident from 10 mg/ml of wCS and 100 mg/ml of eCS, suggesting that eCS is less cytotoxic. When mice (n = 10/group) received a single intratracheal wCS or eCS daily for 14 days, wCS yielded 40 % mortality, whereas eCS showed none. Both wCS and eCS did not significantly affect the weight of the body and of vital organs, except the lung. Biochemical analyses of mice blood indicated no damage to liver or kidney. However, unlike eCS, wCS significantly increased the level of IgE in serum. Collectively, our results show that eCS was less toxic than wCS, suggesting that CS prepared with 50 % ethanol is preferential over the conventional way of preparing CS.

• 대한토목학회논문집
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• 제33권5호
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• pp.1777-1783
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• 2013

유량측정방법 중에서 파샬플륨을 이용하는 방법은 유속이 매우 느리거나 토사유입이 많은 지점에서 상대적으로 유리하다. 국제표준화기구(ISO : International Organization for Standardization)에 파샬플륨의 규모별 규격화된 경험식이 제시되어 있지만, 규격을 따르지 않는 파샬플륨에 대한 수리실험이나 수치모의를 통한 연구는 다소 부족한 실정이다. 따라서 본 연구에서는 ISO 규격 파샬플륨에 대하여 경험식과 수치모의를 비교하여 파샬플륨에 대한 수치모의의 적정성을 검토하였고 현장 여건 등의 이유로 ISO 규격을 따르지 않는 파샬플륨은 유량산정공식을 얻기 위해서 수리실험을 수행해야만 했다. 이러한 임의형상의 파샬플륨에 대하여 동일 조건의 수리실험 및 수치모의 결과를 비교 검토하였다. 그 결과 수치모의가 파샬플륨의 수심과 유량을 적절하게 모의하고 있음을 확인하였다. 이 결과를 이용하여 임의형상에 대한 무차원 유량산정공식을 도출하였으며, 식을 통해 산정된 값과 실험값을 비교하였다. 그 결과 오차는 최대 2.3%로 나타났다. 파샬플륨의 규모결정시 실제 지형과 유입부 형상 등을 고려한 수치모의를 수행한다면 수치모의에 기초한 유량산정공식을 쉽게 도출 할 수 있을 것이다. 또한, 복잡한 수행과정으로 인해 오차가 발생하기 쉬운 수리모형실험을 경제적으로 보완할 수 있을 것으로 판단된다.

• 대한한의학방제학회지
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• 제6권1호
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• pp.119-139
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• 1998

간경변(肝硬變)은 각종(各種) 만성미만성간염(慢性彌滿性肝炎)이나 광범위(廣範圍)한 간장실질(肝臟實質)의 손상(損傷)이 계속적(繼續的)으로 발전(發展)하여 이루어진 결과(結果)이다. 주(主)된 병리적(病理的) 특징(特徵)은 간세포(肝細胞)의 변성(變成), 괴사(壞死) 후(後)에 나타나는 섬유조직(纖維組織)의 증식(增殖), 간세포(肝細胞)의 결절상(結節狀) 재생(再生), 가소엽(假小葉)의 형성(形成) 등(等)으로서, 이들 세가지의 변화(變化)가 뒤섞여 진행(進行) 되는 가운데, 간내(肝內) 혈관망(血管網)이 감소(減少)하거나 혈관망(血管網)에 이상(異狀) 함몰(陷沒)이 발생(發生)하는 것이다. 주(主)된 임상표현(臨床表現)은 간기능감퇴(肝機能減退)와 문맥압(門脈壓) 상승(上升)으로 인(因)한 비종대(脾腫大), 복수(腹水), 복벽정맥(腹壁靜脈)의 노장(怒張), 식도(食道)와 위저정맥(胃底靜脈)의 노장파열(怒張破裂), 간성혼수(肝性昏睡) 등(等)이 나타난다. 한의학(韓醫學)의 범주(範疇)로는 '적취(積聚), 징가, 황달(黃疸), 고창(鼓脹), 협통(脇痛), 단복창(單腹脹), 비괴' 등(等)에 해당(該當)되는 것으로 습열(濕熱)이 구울(久鬱)함에 따라 간(肝), 비(脾)가 손상(損傷)되고 이것이 더욱 오래되어 기체혈어(氣滯血瘀)로 발전(發展)하게 되는 병리변화(病理變化)를 갖는다. 이에 담도결찰(膽道結紮) 및 dimethylnitrosamine의 복강투여(腹腔投與)로 간경화(肝硬化)를 유발(誘發)하고, 울증(鬱證)에 다용하는 익국환과 익국보화환이 이러한 병증(病症)에 간기능보호작용(肝機能保護作用)이 있는가를 관찰(觀察)하고, 한의학적(韓醫學的) 병증(病症)의 분류(分類)에 따라 간질환(肝疾患)에 대(對)한 치료(治療)의 가능성(可能性)을 알아보고자 본(本) 실험(實驗)을 실시(實施)한 결과(結果), 유의성(有意性) 있는 결과(結果)를 얻었기에 보고(報告)하는 바이다.

• 대한한의학방제학회지
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• 제18권1호
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• pp.57-77
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• 2010

Objective : This study reviews the recent trend of oriental medical prescription research. The data examined are the articles published in the Korean Journal of Oriental Medical Prescription from 1990 to 2009. Method : The data are retrieved through the internet database Oriental Medicine Advanced Searching Integrated System (OASIS) and the collection of the Korean Journal of Oriental Medical Prescription. The number of articles examined is 385, published in 25 volumes of the journal. This study examines the nature of the articles, research methods, subjects, and author information. Research subjects are sorted out by the OASIS key words for the articles published before 1999, and by key word indexes cited in the abstracts for the articles published sinceafter. Results : Among the 385 articles collected, 206 are research articles, 143 philological articles, 35 case studies, and 1 special contribution. A majority of research articles are experimental studies (199 articles or 96.6%), while clinical reports (5 articles or 2.43%), and others studies (2 articles) occupy a small portion. Most of experimental studies (183 articles or 91%) examine the effectiveness of certain prescriptions or treatments. Among the effectiveness studies, 114 articles (62.3%) employ in vivo experiment design, 52 articles (28.42%) in vitro experiments, and 17 articles (9.29%) both in vivo and in vitro experiments. In terms of research subject, the most frequently indexed key words are hepatotoxicity among diseases (9 articles), Bojungikgitang (Bu-Zhong-Yi-Qi-Tang) among prescriptions (10 articles), Buja (Acontii Tuber) among meteria medica (4 articles), immunity and anti-oxidation among efficacy terminology (6 articles each), and Donguibogam(東醫寶鑑) among references in the key words (25 articles). Universities are the main affiliation of authors (76.42%), followed by university hospitals (6.71%), non-academic research institutes (5.55%), local clinics (4.67), academic research institutes (2.81%), hospitals (2.38%), and others (1.44%). The most affiliated institute of the first and correspondent authors is Wonkwang University. In terms of authorship, co-authorship outnumbers sole-authorship by 82.08% to 17.92%. The proportion of authors of a single article is 63.54% which is near the author productivity distribution described by Lotka's law.