• 멤브레인
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• 제13권1호
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• pp.9-19
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• 2003

무전해 PCB 도금 공정 수세액을 분리막으로 처리하여 투과수는 공업용수로 재사용하고 유가금속인 금(Au)을 회수하는 방법에 관하여 연구하였다. 역삼투 분리막 테스트 셀을 이용하여 수세액 처리에 적합한 분리막을 선정하였으며 scale-up을 위한 나권형 모듈 투과 실험을 실시하였다. 먼저, (주)새한에서 생산되는 RO-TL(tap water, low pressure), RO-BL(brackish water, low pressure), RO-normal(for water purifier)막으로 투과실험하였으며 그 중 RO-TL막이 soft etching, 촉매 및 Ni 수세액 처리에 우수한 것으로 판명되었다. 따라서 RO-TL막으로 제작한 나권형 가정용 정수기 모듈로 7bar, $25^{\circ}C$에서 scale-up 실험을 수행하였다. Au수세액의 투과 유속은 약 30 LMH로서 가장 높았으나 Au 제거율이 80% 미만이었다. Pd, Ni 및 soft etching 수세액의 투과유속은 각각 약 22, 17, 10 LMH 정도이며 Pd의 제거율은 85% 이상, Ni 및 Cu 제거율은 97% 이상이었다. 또한 Au, Ni 및 Cu 이온이 함유된 수세액 중 유가금속인 Au를 선택적으로 회수하기 위하여 NF막을 사용하였다. Au수세액 중 Ni 및 Cu 이온은 대부분 제거되었으며 투과액 중에 Au이온이 81.9% 존재하였고 계속하여 RO-TL막으로 Au를 농축 회수하였다. 마지막으로 4"직경의 NF 및 RO-TL 나권형 모듈을 연속적으로 사용하여 Au를 효과적으로 회수할 수 있음을 재확인하였다.인하였다.

• 유통과학연구
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• 제12권8호
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• pp.43-54
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• 2014

Purpose - This study was based on a theoretical consideration of the structural relationship between the support and control of the franchisor and the satisfaction and strategic response (voice, loyalty, exit, neglect) of the franchisee. First, based on the preceding research, this study systematically organized the type of support and control of the franchisor. Second, the study examined the effects of a franchisor's support and control on the expectancy disconfirmation between affiliated franchisees' expectations before a franchise agreement and performance after operating an affiliated store. Third, the study looked into the effects of expectancy disconfirmation relating to a franchisor's support and control on an affiliated franchisees' general satisfaction. Fourth, this study examined the influence of the general satisfaction of a franchisee on affiliated franchisees' response strategies. Research design, data, and methodology - In this study, the population comprised the nation's franchisors, and the sample comprised franchisees conducting business in Seoul and Gyeonggi-do. A self-administered questionnaire was used; the author and examiner explained the study's parameters to the interviewees in advance, to lessen the rate of rejection of the answers and to maintain reliability. The author distributed 350 copies of the questionnaire and collected 327 copies (93.4%). The author removed 54 copies of the sample, as these copies belonged to franchisees that were not registered by the Fair Trade Commission and/or were thought to have either defects or inadequate answers. The author selected an effective sample of 273 copies to enter data and to do the statistical analysis. Results - Both a reliability analysis and a confirmatory factor analysis were performed to measure reliability and validity, and a structural equation model was used to conduct the hypothesis test and investigate the models. The hypothesis was tested (Table 5). The models had a suitable fit, for instance, χ² = 447.663(df = 212, p = .000), χ²/df = 2.112, GFI = .881, AGFI = .858, RMR = .083, RMSEA = .067, NFI = .932, and CFI = .961. The hypothesis test results were as follows. Hypothesis 1 was accepted (C.R. = -2.339, p = .019). Hypothesis 2 was accepted (C.R. = 15.213, p = .000). Hypothesis 3 was accepted (C.R. = -2.631, p = .006). Hypothesis 4 was accepted (C.R. = 16.271, p = .000). Hypothesis 5 was accepted (C.R. = 2.391, p = .017). Hypothesis 6 was accepted (C.R. = 5.777, p = .000). Hypothesis 7 was accepted (C.R. = 17.153, p = .000). Hypothesis 8 was accepted (C.R. = 24.746, p = .000). Hypothesis 9 was accepted (C.R. = -10.150, p = .000). Hypothesis 10 was accepted (C.R. = -12.124, p = .000). Conclusions - The research results showed that expectations for a franchisor's support and control had a significant influence on expectation disconfirmation in a negative way, whereas the performance of support and control were found to have a significant influence on expectation disconfirmation in a positive way. In addition, the expectation disconfirmation of support and control was found to have a significant influence on satisfaction of franchisees in a positive way. Generally, regarding the research on control, control is found to have a negative influence on the satisfaction of franchisees, but this study proves that control is found to affect it in a positive way through conformity.

• 인지과학
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• 제32권3호
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• pp.117-139
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• 2021

짧은 시차를 두고 출현하는 기억과 검사배열 사이에 차이 항목의 유무를 찾아내는 변화탐지 원리는 검사배열 출현 시 기억항목들과 견주어 차이가 있는 한 항목을 탐색한다는 점에서 시각탐색 원리와 닮아있다. 본 연구는 두 과제 사이의 이러한 유사성을 배경으로, 시각단기기억 기반 변화탐지 과제에서 변화의 출현 가능성 증감이 변화탐지 반응의사결정에 미치는 영향 즉 변화출현확률 효과의 양상을 조사했다. 이를 위해 네 개의 색상 사각형에 뒤이어 출현한 또 다른 네 개의 색상 사각형 사이의 색상들을 비교해 색상 변화 항목의 유무를 판단하는 단순세부특징 변화탐지 과제를 실시했다. 변화 항목의 출현 가능성은 전체 시행 대비 20, 50 및 80% 확률로 처치되었으며 그에 따른 변화탐지 수행 오류와 탐지민감도 및 반응시간을 분석했다. 그 결과 변화 항목의 출현 가능성이 증가할수록 오경보는 증가하고 실수 반응은 감소했으며 정기각 반응시간 또한 지연된 것이 관찰되었다. 이 변화출현확률 효과는 시각탐색 과제에서 표적의 출현 가능성 증감에 따라 관찰되는 표적출현확률 효과와 매우 유사했으며 이는 두 효과를 초래하는 배경 원리가 서로 닮아있을 가능성을 시사한다.

• 마케팅과학연구
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• 제18권4호
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• pp.33-59
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• 2008

This paper aims to analyse the preference for German farm tourism among the German population. For this reason, we conducted an empirical study in Germany during summer 2007 and we applieda structural equation model based on partial leasts quares(PLS) to analyse the data. In the following chapters we will introduce the literature review and our conceptual frame work. We will then outline the procedures we adopted and the results of the empirical analysis. In the final part so me conclusions will be presented and a discussion will follow in order to draw the future directions of our research. According to our hypotheses, the possibility that agri-tourism enters in the evoked set of an individual is higher: H1: The higher the information degree about it. H2: The lower the influence of the social stimuli. H3: The higher the physical exposure to it (experience). H4: The higher the wellness image of agri-tourism. H5: The higher the traditional image of agri-tourism. H6: The higher the exciting image of agri-tourism. H7: The higher the perceived value for money. Our further hypotheses affirm that the possibility that agri-tourism enters in the evoked set of an individual is higher: H8: The lower the perceived risk. H9: The higher the motive to enjoy a holiday in the nature. H10: The higher the motive to enjoy a sport holiday. H11: The lower the motive to have an organized holiday. H12: The lower the motive to have a holiday abroad. H13: The lower the motive of action and night life. H14: The higher the motive to spend a holiday with the family. H15: The lower the motive to spend a city holiday. Finally, our model has some socio-demographics data. As we mentioned before, German agri-tourism has traditionally been the travel destination of large-size families, with low-to-middle income. For that reason, our final hypothesises are the following: the possibility that agri-tourism enters in the evoked-set of an individual is higher: H16: The higher the number of family members. H17: The lower the family income. Since in this study we use a path model with a PLS approach, we are able to state some interrelations among the exogenous latent variables: H18: The motive of sport holiday has a positive influence towards nature motives. H19: The physical exposition to agri-tourism has a positive influence toward information. H20: The motive of family holiday has a negative influence toward the motive of action and night life. H21: Social stimuli have a positive influence towards individuals risk perceptions. H22: Social stimuli have negative influence towards experience. Data for this study were gathered via administrated questionnaires during the summer 2007 within the frame of an academic "marketing research" course. The corresponding t-values are assessed using the bootstrapping method with 500 re-samples. In our model 61% of the degree of appreciation of German agri-tourism (evoked set) is explained by five independent variables: value for money ($0.335^{{\ast}{\ast}{\ast}}$) (H7) experience ($0.267^{{\ast}{\ast}}$) (H3), exciting image ($0.204^{\ast}$) (H6) organisation ($-0.162^{\ast}$) (H11) and holiday abroad ($-0.156^{\ast}$) (H12). The variance explained ($R^2$) for the other endogenous variables are the following: nature 24.3%, information 14.1%, action holiday 13.8%, risk perception 5.8% and experience 2.4%. An overview can be inferred from table 5. The results also allow us to test each of the proposed hypotheses. With exception of organization and abroad, none of the others travel style factors (H9 to H15) seem to have any significant impact towards evoked set which leads to the rejection of the respective hypotheses. As expected, social stimuli have a significant influence on individuals' risk perception (H21 accepted), however neither the former nor the latter have a valuable impact on evoked set (rejection of H2 and H8). Besides, since the influence of social stimuli towards experience is not significant, also H22 has to be rejected. Experience influences information (H19 accepted) but the latter does not affect significantly the evoked set (H1 rejected). Both H4 as well as H5, referring respectively to the perceived images of German agri-tourism as a wellness destination and the traditional image of the German farm tourism have to be rejected. Finally, none of the demographic data included in the model explains significantly the variance of the factor evoked set. Therefore neither H16 nor H17 has been accepted. As far as the interrelation between sport and nature (H18) and family and action (H20) are concerned, the stated relationship among these variables has been statistically confirmed. Our path model based on partial least squares shows the factors influencing the preference for farm tourism in Germany. Among others value for money and experience are the most significant ones. Practical implications are discussed.

• 한국산학기술학회논문지
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• 제21권6호
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• pp.212-217
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• 2020

본 연구의 목적은 Bollerslev(1986)의 GARCH 모형을 이용하여 제주지역 감귤가격의 시계열적 특성과 가격변동성(price volatility)에 대한 실증분석을 수행하는 것이다. 본 연구의 주요결과는 다음과 같이 요약된다. 첫째, 감귤 가격 변화율의 시계열이 정규분포가 아닌 꼬리가 두터운 분포를 지니고 있는 것으로 나타났다. 이는 Jarque-Bera 통계량이 1%의 유의수준에서 감귤 가격변화율의 시계열의 분포가 정규분포라는 귀무가설을 기각함으로써 검증되었다. 둘째, Ljung-Box Q 통계량을 통해 감귤 가격변화율 시계열 간 상관관계가 높은 것으로 분석되었으며, 이는 ARCH-LM 검정을 통해 통계적으로 검증되었다. 셋째 GARCH(1,1) 모형 추정결과, 평균방정식의 상수항을 제외하고는 모든 계수의 추정 값이 1%의 유의수준에서 통계적으로 유의한 결과를 보였다. 그리고 분산방정식의 지속성 모수(λ=α₁+β₁) 값이 1에 근접한 것으로 추정되었다. 이는 현재와 유사한 변동성 수준이 장래에도 지속될 가능성이 매우 높은 것으로 해석된다. 그리고 이러한 결과는 제주감귤 가격변화율 시계열에서도 기존의 선행연구에서처럼 '변동성 군집(volatility clustering)' 현상이 나타나고 있음을 밝혀낸 것이다. 끝으로, 본 연구의 결과는 정부의 감귤 수급조절정책을 수립하는데 유용한 기초 자료로 활용될 수 있을 것으로 기대된다.

• 한국세라믹학회지
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• 제42권3호
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• pp.165-170
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• 2005

Sol-gel 공정에 의해 제조된 세라믹 분리 막은 보다 순수한 재료를 이용할 수 있고, 균일성을 향상시킬 수 있을 뿐 아니라 다양한 복합체도 넓은 범위에서 반응을 유도할 수 있다는 장점을 가지고 있어 많은 연구가 진행되고 있다. 본 연구에서는 sc,1-gel 공정을 이용하여 Tetraethyl ortho-silicate(TEOS)-Polyethylene glycol(PEG)계 organically modified silicate(ORMOSt)sol을 합성하였다. Polymer분자량을 변수로 하여 sol 합성 후 특성 변화를 점도와 겔화 시간을 측정함으로써 관찰하였다. 합성된 sol을 다공성 담체 위에 dip-coating법을 이용하여 막을 제조하였으며, SEM관찰을 통해 분리 막의 미세구조를 확인하였다. 합성 복합 막의 Oil/water 에멀젼의 처리효율을 cross-flow 타입의 막 분리 장치를 이용하여 확인하였다. Ormosilsol은 유기물의 분자량이 증가될수록 보다 쉽게 코팅 층을 형성 시킬 수 있었고, 담체를 용매에 담지 시켜 코팅 물질이 담체의 기공내로 침투될 때의 모세관력을 줄임으로써 크랙이 방지된 얇은 막을 얻을 수 있었다. Colloidal sol 코팅 막에 비해 ormosil sol코팅 막은 분리효율 뿐 아니라 flux 특설이 시험 5분경과 시점에서 약 $200\;l/m^2h$이상 향상되었음을 확인 할 수 있었다.

• 구강회복응용과학지
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• 제19권4호
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• pp.297-308
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• 2003

Face-bow is used to transfer models to the articulator in diagnosing the patient or treating problems associated with occlusion. However, there have been few reports on the reliability of the face-bow procedure and the relationship between the experience of the operator and the reliability of the face-bow procedure. The purposes of this study are to examine the reliability of the face-bow procedure and to evaluate whether the face-bow transferring has any training effect. Nine dentists working at M hospital conducted a face-bow transfer in one patient having a normal dentition and interdental relationship. The procedure was done two times a week for four weeks. The maxillary model was mounted to the articulator every time, then the landmarks on the maxillary right first molar, the maxillary left central incisor, and the maxillary left first molar were measured with a special three-dimensional instrument. These data were input into a computer, and evaluated statistically. The results were as follows ; 1. When examined with ANOVA test, the results were p=0.2040 in maxillary right first molar, p=0.0578 in maxillary left incisor, and p=0.1433 in maxillary left first molar. There was no significant(0< $p{\leq}0.05$). 2. Training 1) The correlation coefficient between trial and rejection was -0.578 when analyzed with T-distribution. The more we tried, the less errors we found. 2) When the S.D. of the first three trials was compared to the S.D. of the last three trials in face-bow transfer, the results showed that the former was larger than the latter in thirty-nine times, and the latter was larger than the former in fifteen times. The more we tried face-bow transfer, the less errors we found. 3. When the S.D. of x, y, z coordinates were examined, the S.D. of x coordinates had the largest measurement in five times, the S.D. of y coordinates had the largest measurement in four times, and the S.D. of z coordinates had the largest measurement in nine times. The possibility which the error can occur in z coordinate was the highest.

• 한국동물위생학회지
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• 제42권4호
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• pp.193-200
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• 2019

Blood test is a useful tool in establishing medical treatment for livestock. It provides information such as disease diagnosis, treatment effects, prognostic judgment, and health status. This study compared the value of erythrocytes and leukocytes among conventional, transgenic miniature, and transgenic conventional pigs aged six months to 24 months. Further, it analyzed the aspects of hematological value changes according to the pigs' ages. As a result, the number of red blood cells (RBC), which include hemoglobin, and hematocrit, and the number of white blood cells (WBC), which include neutrophils, and lymphocyte, were high among transgenic miniature pigs, compared with the conventional and transgenic conventional pigs. Conventional pigs showed similar values of RBC and WBC regardless of transgenesis. In comparing their age, the RBC decreased as the age increased compared with the pigs among all the three groups aged of 6~12 months. On the other hand, WBC and neutrophils showed no significant difference regardless of different ages among all the three groups. However, various counts in RBC and WBC were mostly found to be higher in each age in transgenic miniature pigs than in conventional and transgenic conventional pigs. The results of this study show that the values of RBC and WBC were generally higher in transgenic miniature pigs than in conventional and transgenic conventional pigs. Based on this research, hematological values can be widely used in diagnosing diseases or checking the health status of transgenic pigs that are used as disease models, organ transplant source and alike.

• 한국음향학회:학술대회논문집
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• 한국음향학회 2002년도 하계학술발표대회 논문집 제21권 1호
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• pp.115-118
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• 2002

화자인식에 사용하는 파라미터는 화자의 특징을 충분히 표현함과 더불어 발성 시마다 변동이 작은 것이 바람직하다. 즉, 파라미터의 화자내의 변이보다 화자간의 변이가 큰 특성을 가져야 화자간의 구분이 용이하다. 또한, 화자간 오류를 최소화하기 위해 화자간 구별이 뚜렷한 특징 파라미터뿐만 아니라 분별력이 뛰어난 인식방법도 필요하다. 최근의 실험결과들을 살펴보면 발성기관에 의한 정적인 특징뿐 아니라, 발성습관에 의한 동적인 특징을 같이 이용함으로써 보다 정확한 인식결과를 얻고 있다. 따라서 본 논문에서는 이러한 문제점을 해결하기 위해 다음과 같이 제안한다. 음성의 특징벡터로 운율정보 사용을 제안한다 현재 화자인식 시스템에서 일반적으로 많이 사용되고 있는 특징벡터는 스펙트럼 정보를 모델링하고 있는 것으로 비잡음 환경에서 종은 성능을 보이고 있다. 그러나 잡음 환경변화에 크게 왜곡되며 인식율이 현저하게 저하되는 문제점이 나타난다. 그러므로 본 논문에서는 음성의 동적 변화를 측정할 수 있는 세그먼트로 분할한 피치열을 변경하여 인식의 특징패턴으로 사용한다. 이는 문장의 운율정보를 보여주는 것으로 소음환경에서 강인한 특성을 보였다.

• 대한치과보철학회지
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• 제44권2호
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• pp.250-263
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• 2006

Statement of problem: Ti-alloy has been used widely since it was produced in the United States in 1947 because it has high biocompatibility and anticorrosive characteristics. Purpose: The pure titanium, however, was used limitedly due to insufficient mechanical charateristics and difficult manufacturing process. Our previous study was focused on the development of a new titanium alloy. In the previous study we found that the Ti-Ta-Nb alloy had better mechanical characteristics and similar anticorrosive characteristics to Ti-6Al-4V Material and methods: In this study, the cytotoxicity of the Ti-Ta-Nb alloy was evaluated by MTT assay using MSCs(Mesenchaimal stem cells) and L929 cells(fibroblast cell line). The biocompatibility of the Ti-Ta-Nb alloy was performed by inserting the alloy into the femur of the rabbits and observing the radiological and histological changes surrounding the alloy implant. Results: 1. In the cytotoxicity test using MSCs, the 60% survival rate was observed in pure titanium, 84% in Ti-6Al-4V alloy and 95% in Ti-10Ta-10Nb alloy. 2. In the animal study, the serial follow-up of the radiographs showed no separation or migration revealing gradual bone ingrowth surrounding the implants. Similar radiographic results were obtained among three implant groups pure titanium, Ti-6Al-4V alloy and Ti-10Ta-10Nb alloy. 3. In the histologic examination of the bone block containing the implants. the bone ingrowth was prominent around the implants with the lapse of time. There was no signs of any tissue rejection, degeneration, or inflammation. Active bone ingrowth was observed around the implants. In the comparison of the three groups, the rate of bone ingrowth was better in the Ti-10Ta-10Nb alloy group than those in pure titanium group or Ti-6Al-4V alloy group. In conclusion, Ti-10Ta-10Nb alloy revealed better biocompatibility in survival rate of the cells and bone ingrowth around the implants. Therefore we believe a newly developed Ti-10Ta-10Nb alloy can replace currently used Ti-6Al-4V alloy to increase biocompatibility and to decrease side effects. Conclusion: In conclusion, Ti-10Ta-10Nb alloy revealed better biocompatibility in survival rate of the cells and bone ingrowth around the implants. Therefore we believe a newly developed Ti-10Ta-10Nb alloy can replace currently used Ti-6Al-4V alloy to increase biocompatibility and to decrease side effects.