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        검색결과 20

        1.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study aimed to identify factors affecting the duration of traffic incidents in tunnel sections, as accidents in tunnels tend to cause more congestion than those on main roads. Survival analysis and a Cox proportional hazards model were used to analyze the determinants of incident clearance times. METHODS : Tunnel traffic accidents were categorized into tunnel access sections versus inner tunnel sections according to the point of occurrence. The factors affecting duration were compared between main road and tunnel locations. The Cox model was applied to quantify the effects of various factors on incident duration time by location. RESULTS : Key factors influencing mainline incident duration included collision type, driver behavior and gender, number of vehicles involved, number of accidents, and post-collision vehicle status. In tunnels, the primary factors identified were collision type, driver behavior, single vs multi-vehicle involvement, and vehicles stopping in the tunnel after collisions. Incidents lasted longest when vehicles stopped at tunnel entrances and exits. In addition, we hypothesize that incident duration in tunnels is longer than in main roads due to the reduced space for vehicle handling. CONCLUSIONS : These results can inform the development of future incident management strategies and congestion mitigation for tunnels and underpasses. The Cox model provided new insights into the determinants of incident duration times in constrained tunnel environments compared to open main roads.
        4,000원
        2.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The process control methods based on the statistical analysis apply the analysis method or mathematical model under the assumption that the process characteristic is normally distributed. However, the distribution of data collected by the automatic measurement system in real time is often not followed by normal distribution. As the statistical analysis tools, the process capability index (PCI) has been used a lot as a measure of process capability analysis in the production site. However, PCI has been usually used without checking the normality test for the process data. Even though the normality assumption is violated, if the analysis method under the assumption of the normal distribution is performed, this will be an incorrect result and take a wrong action. When the normality assumption is violated, we can transform the non-normal data into the normal data by using an appropriate normal transformation method. There are various methods of the normal transformation. In this paper, we consider the Box-Cox transformation among them. Hence, the purpose of the study is to expand the analysis method for the multivariate process capability index using Box-Cox transformation. This study proposes the multivariate process capability index to be able to use according to both methodologies whether data is normally distributed or not. Through the computational examples, we compare and discuss the multivariate process capability index between before and after Box-Cox transformation when the process data is not normally distributed.
        4,000원
        5.
        2014.11 구독 인증기관 무료, 개인회원 유료
        보증데이터의 분석방법은 크게 두 가지로 분류할 수 있다. 첫째, 현상파악이다. 현상 파악은 각 부품별 보증클레임데이터를 이용하여 각부품의 현 수준을 분석하는 방법으 로 단변량 분석방법이다. 즉 부품의 현 수명(신뢰도)를 분석할 수 있는 생명표법, 카랜 마이어 방법이 대표적이라고 할 수 있다. 둘째, 고장원인분석이다. 부품의 고장에 다양 한 인자가 영향을 줄 것이다. 생산부터 고객의 사용조건까지 다양할 것이다. 이처럼 단순히 사용시간을 가지고 분석하는 것이 아닌 다양한 원인변수를 통해서 원인을 파 악하는 다변량 방법이다. 본 연구에서는 다변량 방법 중 Tree기법과 Cox모형을 적용 하고자 한다. 두 방법을 제시하는 이유는 이 두 방법의 서로의 장단점을 보완하여 최 적을 결과를 얻기 위함이다. Tree의 장점은 결과 해석이 다른 모형에 비해 쉽다. 단점 은 유의한 변수가 무엇인지는 알 수 있으나 정량적으로 표현하기 어렵다. 반면에 COX 모형의 경우는 위험도를 정량적으로 표현할 수 있다. 즉 다양한 인자의 기여도를 비교 적 쉽게 찾을 수 있다. 보증데이터는 다양한 정보와 고장에 대한 정보를 가지고 있으 며 이를 바탕으로 원인분석이 가능하다. 본 논문에서는 다양한 인자를 고려하여 고장원인을 추정할 수 있는 다변량 분석방 법을 보증데이터에 적용해 보았고, 실제 유의함을 확인하였다. 특히 Tree 모형 및 Cox 모형를 통해서 서로의 장단점을 보완하였고, 더욱 정확한 원인을 찾을 수 있었다.
        4,000원
        8.
        2006.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cyclooxygenase(COX)-2 is an enzyme engaged in the synthesis of prostaglandin(PG) and is upregulated by inflammation. It is related with the expression of the vascular endothelial growth factor(VEGF) in the angiogenesis of granulation tissue. By using immunohistochemical stains, the expressions for COX-2 and VEGF were evaluated according to the degree of inflammation and the type of lesion, and the correlation between the expressions were investigated in the 39 periapical lesions (7 periapical granulomas, 7 periapical granulomas with epithelium, 25 periapical cysts) and 13 dentigerous cysts. The expression rate of COX-2 in histiocytes of periapical lesions(97.4%) was significantly higher than that of dentigerous cysts(69.2%)(p=0.0032). The expression rate of VEGF was highest in plasma cells in the periapical lesions(69.4%) and in dentigerous cysts(69.2%). COX-2 expression rate in endothelium and VEGF expression rate in epithelium were significantly higher in the periapical cysts than in the periapical granuloma and. VEGF expression rate in endothelium of the periapical lesions was increased in cases with resolving inflammation. For the periapical lesions, epithelial expression of COX-2 and VEGF showed a positive relationship(p=0.0301), and endothelial COX-2 expression revealed positive relationship with VEGF expressions in epithelium(p=0.0008), in histiocytes(p=0.0136), and in endothelium(p=0.0439). According to these findings, as the periapical lesion progressed from granuloma to cyst, the expressions of COX-2 and VEGF were increased. COX-2 expression was significantly correlated with VEGF expression, which suggests that COX-2 seems to be involved in the progression of periapical lesion by inducing the expression of VEGF.
        4,000원
        10.
        2005.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cyclooxygenase- 2 (COX-2) is an inducible enzyme that is not found in normal conditions,. but is induced by a varie ty of pathophysiologic conditions of tissues by growth factors. inflammatory stimuli. oncogenes and tumor promoters, COX-2 is upregulated in a number of epithelial cancers. including in oral premalignant and malignant lesions, The mode of action of COX-2 in carcinogenesis may include mutiple mechanisms that may be acting at different stages of malignant disease, In this study. the expression of COX- 2 protein was assessed quantitatively 없d qualitatively by immunohistochemistry during DMBA-induced hamster buccal pouch carcinogenesis, The immunoreactivity for COX-2 protein increased as the tissue passed from hyperplasia to dysplasia and SCC, The highest mean expression was SCC at 14 week, The differences between COX-2 expression in the normal and that the dysplastic and carcinomatous lesions was statistically significant, In addition. the mean values of COX -2 expression in the stromal cells increased gradually during malignant progression, The results suggest that increased COX-2 expression may be associated with the chemically induced carcinogenic progression of hamster buccal pouch model, The gradual increasing COX-2 expression de tected during the progressive manner toward more malignant lesions shows that the COX-2 protein can have an important role in both the early and the later stages of multistep oral carcinogenesis
        4,000원
        11.
        2004.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Department of Oral Pathology, Dental Science Research Institute, College of Den디'suy, Chonnam National University It is well known that the expansion of radicular and dentigerous cyst is related to the change of osmotic pressure, while the prolifera디on ofthe 비피19 epithelium in odontogenic keratocyst. When the dentigerous cyst and odontogenic keratocyst has secondary infection, they present the loss of unique sπuctures and epithelial hyperplasia. There is a question whether inflammatory reaction affects cystic formation, expansion and their treatment. Present study is to evaluate the relationship between inflammation and epithelial hyperplasia using immunohistochemial study. Followings are result; 1. 까1e age of patients ranged from 10 to 73 years (mean age, 39 years) in radicular 이5t, 10 to 71 years (mean age, 35 years) in dentigerous cyst and 10 to 54 years (mean age, 23.4 years) in odontogenic keratocyst. The sex distribution of patient distributed 32 cases for male and 16 cases for female in radicular cyst, 13 and 10 in dentigerous cyst and equally 5 and 5 in odontogenic keratocyst. 2. Inflammatory cyst in the present study distributed 44/48 cases (9 1.7%) for radicular cyst, 15/ 23 cases for dentigerous cyst and 1/ 10 case for odontogenic keratocyst. 3. Evaluation of inflammatory reaction and antigen expression, ki-67 , cox-2 and glut-1 expression increase in the inflammatory radicular and dentigerous cyst. 4. In odontoge띠c keratocyst, expression of antigens increase regardless of inflammation. Above results showed that inflammation stimulate the proliferation of lining epithelium leading to cystic expansion.
        4,000원
        12.
        2017.06 서비스 종료(열람 제한)
        The clinical importance of biologic markers remains elusive in gastric cancer. The aim of this study was to evaluate the prognostic value of p53, Ki-67, and COX-2 in gastric cancer. This retrospective study examined based on medical records of postoperative immunohistochemical test of 176 patients who demonstrated high expression of all three biological markers being tested (p53, Ki-67, and COX-2), among 357 gastric cancer patients who underwent surgical resection consecutively. This study demonstrates the correlation with biologic marker between clinical relationship and recurrence free survival (RFS). A positive correlation was observed between the expression of Ki-67 and p53, and a positive correlation was also observed between the expression of Ki-67 and COX-2 Expression of p53 did not correlate with any of the clinicopathological variables examined. Both Ki-67 and COX-2 expression significantly correlated with tumor depth, classified as early gastric cancer and advanced gastric cancer. The expression of COX-2 significantly correlated with tumor differentiation, with more tumors being of the undifferentiated type than of the differentiated type in the COX-2 positive group. A significant difference between p53 and RFS, also COX-2 expression and RFS was observed. This study showed that only p53 and COX-2 have significantly correlated with the RFS of gastric cancer.
        13.
        2015.08 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        본 연구에서는 마늘의 부산물로 발생하는 마늘대의 항산화 및 항염증 효과를 알아보기 위하여 LPS로 염증을 유도한 Raw 264.7 세포에 대한 열수추출물(ASSW)과 70% 에탄올 추출물(ASSE)의 효과를 살펴보았다. ASSW의 폴리페놀 함량은 37.08±1.51 mg(TAE)/g, ASSE의 폴리페놀 함량은 44.7±1.32 mg(TAE)/g 이 함유되어있음을 확인하였다. DPPH 실험과 ABTS+ 실험에서 ASSW, ASSE 모두 농도 의존적으로 증가하였으며, DPPH의 경우 1,000 μg/mL에서 대조군인 Vit.C의 50 μg/mL의 항산화능이 있다는 것이 확인되었고, ABTS+의 경우 500 μg/mL 이상부터 대조군인 Vit.C와 비슷한 효과를 나타냄으로서 ASSW, ASSE 모두 항산화능이 있다는 것을 확인하였다. MTT측정으로 인해 세포 독성을 가지지 않았던 농도대(5, 10, 25, 50, 100 μg/mL)에서 염증 억제 효과를 살펴보기 위해 NO를 측정한 결과 ASSW, ASSE 모두 25 μg/mL에서부터 유의적으로 분비량이 감소함을 확인하였으며 특히 100 μg/mL의 농도에서 약 18%, 23%의 억제 효과를 보였다. 또한 대식세포의 염증성 cytokine인 IL-6, TNF-α, IL-1β 및 PGE2의 분비량을 첨가 농도 의존적으로 억제함을 확인하였다. 특히 PGE2에 대해 ASSW, ASSE 100 μg/mL의 농도에서 약 55%, 60%의 감소효과를 보였다. ASSW의 iNOS, COX-2의 발현 저해효과는 나타내지 못하였지만, ASSE는 100 μg/mL의 농도에서 iNOS의 발현량이 현저하게 억제됨을 확인하였고, COX-2의 경우 농도 의존적으로 저하되어 특히 50 μg/mL, 100 μg/mL의 구간에서 단백질 발현 저해효과가 있음을 확인하였다. 이를 통해 ASSW, ASSE 모두 항산화 효과와 항염증 효과가 있음을 확인하였으며, ASSW 보다 ASSE에서 활성산소종(reactive oxygen species, ROS) 및 ROS에 의해 유발되는 염증을 억제시켜주는 소재가 될수있을 것이라 예상된다.
        15.
        2010.10 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        나비류 추출물은 전통적으로 다양한 활성을 보유하여 의약용으로 사용되어졌다. 5종의 나비(산제비나비[Papilio maackii], 호랑나비[Papilio xuthus], 배추흰나비[Pieris rapae], 남방호랑나비[Eurema hecabe], 왕오색나비[Sasakia charonda])를 이용하여 물, dimethly sulfoxide (DMSO), ehtanol 및 methanol로 추출한 추출물로 항산화 활성 및 Cox-2 promote
        19.
        2005.04 KCI 등재 서비스 종료(열람 제한)
        Five coumarins, psoralen (1), scopoletin (2), isoimperatorin (4), (+)-marmesin (5) and xanthotoxin (6), three chromones, cimifugin (3), hamaudol (7) and sec-O-glucosylhamaudol (10), one sterol, daucosterol (8) and one aliphatic alcohol, galactitol (9) were isolated from the root of Peucedanum japonicum. Their chemical structures were identified by the physicochemical and spectroscopic data by comparing literature values. Among them, compounds 9 and 10 were isolated for the first time from this plant. The anti-inflammatory effects of isolated compounds were examined on cyclooxygenase (COX), compounds 1, 2 and 7 showed inhibitory activity on COX-1 with IC50 values of 0.88, 0.27 and 0.30 mM, respectively. In the test for COX-2 activity, only compound 7 showed significant inhibitory activity with the IC50 value of 0.57 mM. The other compounds exhibited weak inhibitory or no inhibitory activity.
        20.
        2003.04 KCI 등재 서비스 종료(열람 제한)
        I-D-F곡선을 유도할 때 강우자료의 보유연한이 충분하지 않을 경우 지속시간별 강우강도의 변화가 매끄럽게 연결되지 못하는 경우가 발생하기도 한다. 특히 곡선에서, 상대적인 장시간에 강우강도가 크게 되는 문제는 실무적으로 I-D-F 곡선을 이용하는데 큰 혼란을 야기 시킨다. 본 연구에서는 강우자료를 Box-Cox변환을 이용하여 지속시간과 강우강도의 상관관계를 통해 이러한 문제를 해결하는 방법을 제시한다. 산청과 영천의 강우자료에 대한 분석결과 Box-Co