• 제목/요약/키워드: duration ratio

검색결과 1,415건 처리시간 0.025초

마갈드레이트의 합성조건과 그 현탁액의 유동학적 특성 (Synthesis Conditions of Magaldrate and Rheological Characteristics of its Aqueous Suspensions)

  • 신화우;최광식
    • 약학회지
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    • 제40권1호
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    • pp.25-35
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    • 1996
  • Magaldrate. an antiacid was synthesized by reacting magnesium oxide, aluminum sulfate, and dried aluminum hydroxide gel. The optimum synthesis conditions based on the yield of t he product were established by applying Box-Wilson experimental design. It was found that the optimum synthesis conditions of Magaldrate were as follows: Reaction temperature; 61~$85{\circ}C$, concentration of two reactants. Mgo and $Al(OH)_3$: 16~19.8%, molar concentration ratio of two reactants, [MgO]/[$Al(OH)_3$]; 4.2~5.0, temperature of washing water; 36~$41^{\circ}C$ and drying temperature of the product: 76~$80^{\circ}C$. Magaldrate was synthesized under the optimum synthesis conditions and identified by analyzing the chemical composition, and by differential scanning calorimetry and X-ray diffraction method. The Magaldrate sample synthesis under these conditions was used to prepare 15.6% Magaldrate original suspension which was utilized to make 13% Magaldrate suspension dispered in various concentrations of eight types of suspending agents. The acid-neutralizing capacity of 13% Magaldrate suspension dispersed in 0.25% suspending agents was examined by Rosset-Rice method. The maximum pH was reached within 1 minute in all suspension tested, and duration maintained between pH 3~5 was decreased in the order of Na alginate Na silicate(meta) Veegum HV pectin agar>Na>CMC>xanthan gum>bentonite. It was found that the hysteresis loop area was increased with temperature in the case of Riopan Plus and the addition of agar, whereas the area was decreased with temperature in the case of the addition of Na alginate and xanthan gum. 13% Magaldrate suspension tends to sediment by the addition of bentonite.

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Treatment Outcomes of Pediatric Craniopharyngioma : A 15-Year Retrospective Review of 35 Cases

  • Jo, Kwang-Wook;Shin, Hyung-Jin;Kong, Doo-Sik;Seol, Ho-Jun;Nam, Do-Hyun;Lee, Jung-Il
    • Journal of Korean Neurosurgical Society
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    • 제52권1호
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    • pp.37-41
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    • 2012
  • Objective : The aim of this study was to describe a single center's experience in the management of craniopharyngiomas in children over a 15-year period. Methods : The clinical records of pediatric patients treated for craniopharyngiomas between December 1995 and February 2011 were reviewed. Thirty-five pediatric patients diagnosed with craniopharyngioma were treated, and their medical records and imaging data were analyzed retrospectively. Results : The mean follow-up duration was 76 months (range, 10-195). Overall survival and local control rates at 10 years were $94.7{\pm}5.1%$ and $37.1{\pm}11.9%$, respectively. The female-to-male ratio was 16 : 19, and the mean age was 8.6 years (range, 1-17). Initially, gross total resection (GTR) was performed in 30 patients; subtotal resection (STR) followed by radiotherapy was performed in 5 patients. Of the 14 cases that showed recurrence after GTR, 5 patients were treated with GTR, 1 with radiation therapy (RT), 4 with gamma knife radiosurgery (GKRS), and 4 with subtotal resection followed by RT. No patients who underwent RT or GKRS had recurrences. Two cases with recurrence after STR followed by RT were treated with GTR. One patient died of hormonal insufficiency 64 months after the first surgery. The overall median time progression was 51.2 months (range, 3-182) : 49.7 months in the patients who underwent GTR and 60.2 months in the patients who underwent STR followed by RT. Conclusion : If safe resection is possible, GTR at the initial treatment should be attempted to reduce the tumor recurrence. However, if the tumor recurs after the first surgery, RT or GKRS with/without reoperation may be an effective salvage treatment for recurrent craniopharyngioma.

초등수학 수업의 동기 유발 방법 분석 (An Analysis on the Motivations in the Elementary Mathematics Lessons)

  • 박만구
    • 한국수학교육학회지시리즈C:초등수학교육
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    • 제20권1호
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    • pp.101-115
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    • 2017
  • 본 연구의 목적은 초등 예비교사들의 관점에서 수학 수업을 관찰하면서 동기 유발의 측면을 중심으로 동기 유발의 내용 및 방법, 그리고 예비교사들의 동기 유발에 대하여 분석하는 것이다. 연구 참여자들은 서울 지역의 2학년 또는 3학년에 재학 중인 예비교사 62명이었다. 이 예비교사들이 1주 또는 2주간의 교육실습 중 수학수업의 동기 유발 부분을 집중적으로 관찰한 후, 자신들의 관점에서 수학 수업에서의 동기 유발에 대한 분석한 결과와 의견을 제시하도록 하였다. 연구 결과, 예비교사들은 동기 유발을 주로 학생들의 흥미를 진작하기 위한 것과 주위집중을 위한 것으로 생각하였다. 동기 유발의 시간은 평균 5분 50초이고, 제한된 자료만을 사용하여 동기를 유발하였다. 연구자는 동기 유발 내용 및 방법이 차시의 목표와 세밀하게 연계할 수 있는 방안에 대한 후속 연구를 제언하였다.

저장 마늘의 녹변현상에 관한 연구 (On the Development of Flesh Greening of the Stored Garlic)

  • 김동만;김길환
    • 한국식품과학회지
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    • 제22권1호
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    • pp.50-55
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    • 1990
  • 녹변현상을 나타내는 마늘의 주요 구성성분의 함량을 건전한 마늘과 비교하였고 녹변의 진행에 관련한 몇 가지 인자의 영향에 관한 실험을 수행하였다. 마늘에 함유된 유기산 중 피르브산 및 숙신산, 아미노산 중 아르기닌, 지방산 중 리놀레산 및 리놀렌산은 녹변이 발생하는 마늘이 건전한 마늘에 비해 높은 값을 보였으며 전기영동에 의한 단백질의 양상에 있어서는 45-66.2kd 부근에서 큰 차이를 보였다. 한편 마늘의 녹변반응은 pH, 온도, 반응시간 및 에틸알콜농도에 의존성을 보였으며 pH 5.5의 완충용액에 현탁시켜 $50^{\circ}C$에서 30분간 열처리시 녹변도가 가장 높은 것으로 나타났다.

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한반도 집중호우의 종관적 특성 (The Synoptic Characteristics of Heavy Rain in South Korea)

  • 정관영;류찬수
    • 통합자연과학논문집
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    • 제1권2호
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    • pp.89-114
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    • 2008
  • Interrelationship between heavy rainfalls and related with low-level jets(LLJ) is analyzed by using fifty cases of heavy rainfall events occurred over the Korean peninsula from 1992 to 2001. Those cases are classified with four synoptical features. There are 32% chances that the low pressure exist in heavy rainfall over than 150 mm per day case by case. Secondly Changma front and front zone account for 28% of all cases. The ratio of marine tropical boundary type and trough type record 22% and 18% respectively. The moist and warm south-westerly winds associated with low-level jets have been induced convective instability and baroclinic instability. Therefore, heavy rainfall due to the approach of a low pressure occurred at September and before Changma. During the period of Changma, this type has been happened heavy rainfall when low pressure and stationary front has vibrated south and north. Changma type has longer the duration time of precipitation than other types. Third type, located with marine Tropical boundary, have mainly rained in August and September. The last trough case locally downpoured in short time with developing cell. The occurrence low-level jets related to heavy rainfall has increased over 12.5 m/s wind speed. The result is that 43 heavy rainfalls out of 50 cases reach peak at the time of maximum precipitation intensity. Also, the variation of wet number and K-index corresponded with the variation of wind speed. It is found that the number of frequency of low-level jets with southwestward direction has been increased and these jets are mainly passed from the southwest toward to the northeast of the Korean peninsula in that time.

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CVP 분석을 이용한 면허어업 손실보상액 평가 모형의 도출 (The Derivation of a Model to Estimate Compensation for Damages in Chartered Fisheries by Using CVP Analysis)

  • 정형찬
    • 수산경영론집
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    • 제31권2호
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    • pp.133-153
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    • 2000
  • During the last several decades, Korea has been regarded as one of the fastest growing economies in the world. However, the small size of national land has not met the vigorous demand for land necessary to develop economic infra-structures such as large-scale harbors airports and highways. In order to satisfy the growing demand for land, the Korean government and industry have implemented the national land development programs to reclaim land from the sea fur the several decades. It is certain that these land development programs have resulted in a lot of property disputes between fishermen and public project administrators. This paper is to develop a quantitative model to estimate compensation for damages or restriction of charted fisheries resulting from large-scale public projects. In this paper, the compensation model is derived by using cost-volume-profit analysis framework because the compensation for charted fisheries basically depends on the factors such as the costs, production volume, profit of charted fisheries damaged or restricted by public projects. The model shows that the compensation for damages or restriction of charted fisheries is determined by the average annual profit, damage duration period, and the degree of fishery damages. In addition, the degree of fishery damages measured by the ratio of lost profit to annual average profit turns out to be determined by the following factors: annul profit, unit variable cost, decrease in production volume, the rate of increase in variable cost, and a change in fixed cost. Furthermore, this parer discusses the nam issues related to practices and regulation of the compensation for fishery damages in the current Fishery Act of Korea and suggests some appraisal methods which will be able to lead to theoretically correct and fair compensation for fisheries damages resulting from large-scale public projects.

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교통사고 환자 47례에 대한 임상적 고찰 (The clinical study of the 47 traffic accident victims)

  • 김민정;이수홍;김경호
    • Journal of Acupuncture Research
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    • 제17권3호
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    • pp.250-264
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    • 2000
  • A retrospective study has been carried out for 47 cases of traffic accident victims which was entered to the Dongguk Bundang O. M. Hosp. from Jan 1, 1999 to May 4, 2000. This study was focused on finding out the distribution, pattern of the traffic accidents, clinical characteristics of the patients, motives of their choosing oriental medical treatments, the kinds of oriental medical treatment. This results were as follows : 1. The highest incidence was shown in the age of twenties to thirties as much as 59.6% and the ratio of male to female was 17:30. 2. 80.9% of all patients was injured by car accidents. 68.2% of all patients was injured as drivers and passengers and 19.2% was injured as pedestrians. The highest type in the collision between cars, was rear impact. 3. The number of patient(61.7%) via other hosp. was more than that of the first visitor(38.3%) to our hosp. 4. In admission motives, The patients who had been treated by western medical treatment, expressed the dissatisfaction of that treatment, so hoped to be treated by oriental medical styles. Also The others wanted to be treated by oriental medical methods in the reason of no deep surgical, orthopaedical lesions 5. C-spine sprain(80.9%) was the most frequent out of all patients's diagnosis and then L-spine sprain(51.1%), contusion(46.8%), etc. 6. Head Cervix(80.9%) was the commonest pain region of all patients. and then shoulder back(70.2%), lumbar region(61.7%), etc. 7. In general, the pedestrian injuries were more serious than those sustained in the car as passengers. 8. After discharge, Duration of OPD treatment was long as much as that of admission treatment. 9. At first stage of admission period, Herb medication was frequently prescribed for hwalhyultonglakgige(活血通絡之劑). but As going to end stage, was frequently used for bogi(補氣) bohyul(補血), gudam(祛痰), ansin(安神).

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요통환자 80례에 대한 임상적 고찰 (The Clinical Study on 80 Cases of Low Back Pain Patients)

  • 전성하;류헌식;장병선;김수현;박회진
    • Journal of Acupuncture Research
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    • 제24권2호
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    • pp.155-167
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    • 2007
  • Objectives : This study was performed to evaluate the general distribution and the efficacy of oriental medical treatment for low back pain. Methods: We have selected of the moxa bucket moxibustion. We make a comparative study of the thermodynamic characteristics of moxa bucket moxibustion. We examined combustion times, temperatures, temperature gradients in each period during a combustion of moxa bucket moxibustion made by oak wood. Results : The 80 cases of low back pain patients was analyzed according to the distribution of sex, age, the period of disease, contributing factor, the patient-condition on admission, the symptom on admission, the duration of admission, the reading of the X-ray and the treatment efficacy was evaluated respectively. 1. Female was more than male in the ratio of 1:1.2, and thirties and seventies 25% the most, the acutest phase 46.3% the most, reason unknown 33.8% the most, Grade III 50% the most, L.B.P. only 51.3% the most, the day of 6-10 30% the most, compression Fx 30% the most. 2. In the total treatment result, the good was 51.3%, the excellent 22.5%, the fair 17.5%, the poor 8.8% in order. About 'the effective rate'(the percentage of positive effective treatment cases) of each distribution, the fifties 100% the most, the acutest phase 97.3% the most, the slip down, weight lifting, overuse 100% the most respectively, Grade III 97.5% the most, L.B.P. only 95.1% the most, the day of 11-15 100% the most, HN.P. 93.3% the most. Conclusions : We have known the efficacy of oriental medical treatment for L.B.P. was good and early treatment was better than late treatment and main cause of L.B.P. was degenerative change.

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PRAM을 위한 $Ag_x(Ge_2Sb_2Te_5)_{1-x}$ (x= 0, 0.05, 0.1) 박막의 특성 (Characteristics of $Ag_x(Ge_2Sb_2Te_5)_{1-x}$ (x= 0, 0.05, 0.1) thin films for PRAM)

  • 김성원;송기호;이현용
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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    • pp.21-22
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    • 2008
  • In the paper, we report several experimental data capable of evaluating the phase transformation characteristics of $Ag_x(Ge_2Sb_2Te_5)_{1-x}$ (x =0, 0.05, 0.1) thin films. The $Ag_x(Ge_2Sb_2Te_5)_{1-x}$ phase change thin films have been prepared by thermal evaporation. The crystallization characteristics of amorphous$Ag_x(Ge_2Sb_2Te_5)_{1-x}$ thin films were investigated by using nano-pulse scanner with 658 nm laser diode (power; 1~17 mW, pulse duration; 10~460 ns) and XRD measurement. It was found that the more Ag is doped, the more crystallization speed was 50 improved. In comparision with $Ge_2Sb_2Te_5$ thin film, the sheet resistance$(R_{amor})$ of the amorphous $Ag_x(Ge_2Sb_2Te_5)_{1-x}$ thin films were found to be lager than that of $Ge_2Sb_2Te_5$ film($R_{amor}$ $\sim10^7\Omega/\square$ and $R_{cryst}$ 10 $\Omega/\square$). That is, the ratio of $R_{amor}/R_{cryst}$ was evaluates to be $\sim10^6$ This is very helpful to writing current reduction of phase-change random acess memory.

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차량 네트워크에서 V21 통신을 위한 안정된 라우팅 프로토콜 (Reliable Routing Protocol for Vehicle to Infrastructure Communications in VANET)

  • 김정훈;이수경
    • 한국통신학회논문지
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    • 제34권8B호
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    • pp.839-845
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    • 2009
  • 차량들의 멀티 홉으로 구성되어 있는 Vehicular Ad-hoc Network (VANET)은 차량의 빠른 이동 속도와 빈번한 밀도 변화로 인하여 링크 연결 시간이 짧고 패킷 손실율이 높은 단점을 가지고 있다. 이러한 VANET의 문제점을 해결하기위해 차량의 속도, 이동 방향, 위치 정보를 이용하여 차량의 이동성을 예측하여 높은 링크 연결 시간을 가지는 차량으로 멀티 홉을 구성하려는 연구가 활발히 진행되고 있다. 이러한 연구들은 라우팅 경로의 안정성을 향상시키고 링크 연결 시간을 증가시켰지만 릴레이 노드간 거리가 짧아져 라우팅 경로의 길이와 delay가 길어지는 문제점을 가지고 있다. 본 논문에서는 기존 연구의 라우팅 경로의 길이와 delay가 길어지는 문제점을 해결하기 위한 새로운 라우팅 알고리즘을 제안하고 교차로가 존재하는 시내 도로에서의 차량 이동 예측 알고리즘을 제안하여 효율적이면서도 안정적인 라우팅 경로를 찾는 것을 목표로 한다. 다양한 환경에서의 실험 결과를 통해 우리는 제안하는 알고리즘이 Greedy Perimeter Stateless Routing (GPSR)과 기존 연구 결과들에 비해 더 뛰어난 성능을 보이는 것을 확인하였다.