• Title/Summary/Keyword: Factor model

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Factors which Influence Customers' Intention to Switch from Call-Based Driver-for-hire Services to App-Based Driver-for-hire Services Based on Online to Offline (O2O) Business Model: Focusing on Kakao Driver service (콜 대리업체 서비스에서 O2O 방식이 적용된 대리운전 사업 모델로의 소비자 전환 의도에 관한 연구: 카카오 드라이버를 중심으로)

  • Kim, Daewon;Jeong, Hye Seung
    • The Journal of Society for e-Business Studies
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    • v.21 no.3
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    • pp.51-78
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    • 2016
  • Online-to-offline (O2O) commerce is the new trend that merges online commerce with traditional industries in various fields. The primary purpose of this paper is to find out which factors influence customers' intention to switch from call-based driver-for-hire services to O2O app-based services. This study used variables and factors based on Theory of Switching Intention, and Extended Unified Theory of Acceptance and Use of Technology in order to design research questions. We surveyed 500 users of call-based driver-for-hire services. According to the result of this study, dissatisfaction with the current call-based driver-for-hire services is estimated to be a significant factor that strengthens customers' intention to switch from the call-based driver-for-hire services to the app-based services. Loyalty to the previous call-based driver-for-hire services was not seen as a crucial motivator that causes customers to switch to the new O2O driver service. Switching cost also did not play a key role in explaining the relationship between dissatisfaction with the current call-based service and the intention to use the new app-based service. Performance expectancy, easiness in use, the level of user's knowledge or available assistance in relation to the use of app-based services, and expectancy for reasonable price was found to have meaningful impacts on customers' intention to switch from the call-based driver-for-hire services to the app-based services. Age, gender and user experience on the new service were found incapable of moderating the relationship between aforementioned factors which influence customers' choice of the app-based driver-for-hire service, and customers' intent to switch to the app-based service.

An Analysis of Prognostic Factors in the Uterine Cervical Cancer Patients (자궁경부암 환자의 예후인자에 관한 분석)

  • Yang, Dae-Sik;Yoon, Won-Sub;Kim, Tae-Hyun;Kim, Chul-Yong;Choi, Myung-Sun
    • Radiation Oncology Journal
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    • v.18 no.4
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    • pp.300-308
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    • 2000
  • Purpose :The aim of this study is to analysis of suwival and recurrence rates of the uterine cervical carcinoma patients whom received the radiation therapy respectively. The prognostic factors, such as Papanicolaou (Pap) smear, carcinoembriogenic antigen (CEA) and squamous cell carcinoma (SCC) antigen has been studied. Methods and Materials : From January 1981 to December 1998, eight-hundred twenty-seven uterine carvical cancer patients were treat with radiation therapy. All of the patients were divided into two groups : the radiation therapy only (S2l patients) group and the postoperative radiation therapy (326 patients) group. The age, treatment modality, clinical stage, histopathology, recurrence, follow-up Pap smears, CEA and SCC antigen were used as parameters for the evaluation. The prognostic factors such as survival and recurrence rates were peformed with the Kaplan-Meier method and the Cox hazard model, respectively. Median rollow-up was 38.6 months. Results :On the radiation therapy only group, 314 patients (60$\%$) achieved complete response (CR), 47 patients (9$\%$) showed local recurrence (LR), 78 patients (15$\%$) developed distant metastasis (DM). On the Postoperative radiation therapy group, showed 276 Patients (85$\%$) CR, 8 Patients (2$\%$) LR, 37 Patients (11$\%$) DM. The 5-year survival and recurrence rates was evaluated for all parameters. The statistically significant factors for the survival rate in univariate analysis were clinical stage (p=0.0001), treatment modality (p=0.0010), recurrence (p=0.0001), Pap smear (p=0.0329), CEA (p=0.0001) and SCC antigen (p=0.0001). Conclusion: This study indicated that after treatment, the follow-up studies of Pap smear, CEA and SCC antigen were significant parameter and prediction factors for the survival and recurrence of the uterine cervical carcinoma.

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Optimization Mixture Ratio of Petasites japonicus, Luffa cylindrica and Houttuynia cordata to Develop a Functional Drink by Mixture Design (혼합물 실험계획법에 의한 머위 및 부원료의 혼합비율 최적화)

  • Jeong, Hae-Jin;Lee, Kyoung-Pil;Chung, Hun-Sik;Kim, Dong-Seop;Kim, Han-Soo;Choi, Young-Whan;Im, Dong-Soon;Seong, Jong-Hwan;Lee, Young-Guen
    • Journal of Life Science
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    • v.25 no.3
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    • pp.329-335
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    • 2015
  • This study was performed to determine the optimal ratio of Petasites japonicus, Luffa cylindrica, and Houttuynia cordata, all of which are supposed to have anti-respiratory disease effects, such as against rhinitis. The experiment incorporated a mixture design and included 12 experimental points with center replicates for three different independent variables (Petasites japonicus 30~70%; Luffa cylindrica 10~30%; and Houttuynia cordata 10~30%). Based on this design, the mixture was extracted in hot water at 121℃ for 45 min and anti-allergy and anti-microbial activities were observed. The response surface and trace plot described for the anti-allergy activity showed Petasites japonicas was a relatively important factor. The correlation coefficient (R2) value 82.10% for the inhibition effect of degranulation was analyzed by the regression equation. The analysis of variance showed the model fit was statistically significant (p<0.05). The optimal ratio of the mixture was Petasites japonicus 0.75%, Luffa cylindrica 0.11%, and Houttuynia cordata 0.14%. The anti-microbial activity for each extraction of the mixture was valid on gram-positive, such as Staphylococcus aureus (KCCM 40881) and Staphylococcus epidermidis (KCCM 35494), while it was less effective on gram-negative, such as Escherichia coli (KCCM 11234) and Pseudomonas aeruginosa (KCCM 11328).

Medicinal Herb Extracts Attenuate 1-Chloro-2,4dinitrobenzene-induced Development of Atopic Dermatitis-like Skin Lesions (한약재 단일 추출물 및 복합 추출물을 이용한 아토피성 피부염 억제 효과)

  • Lee, Moon Hee;Han, Min Ho;Yoon, Jung Jeh;Song, Myung Kyu;Kim, Min Ju;Hong, Su Hyun;Choi, Byung Tae;Kim, Byung Woo;Hwang, Hye Jin;Choi, Yung Hyun
    • Journal of Life Science
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    • v.24 no.8
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    • pp.851-859
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    • 2014
  • The present study was designed to investigate whether ethanol extracts of Sophora flavescens (GS), Glycyrrhiza uralensis (GC), Dictamnus dasycarpus (BSP), and their mixtures (GGB-1, -2, -3, and -4) inhibit 1-chloro-2,4-dinitrobenzene (DNCB)-induced atopic dermatitis (AD) in a mouse model. DNCB was topically applied on the dorsal surface of Balb/c mice to induce AD-like skin lesions. The pathological phenotypes of AD, such as erythema, ear thickness, edema, scabs, and discharge, were significantly decreased in the GGB (DNCB + GS:GC:BSP = 3:1:1 mixture)-1-treated groups compared with the other treated groups. The weight of the spleen in immune organs was significantly decreased in the GGB-1-treated groups, whereas the weight of the liver in a control group was similar to that of the groups treated with the samples. Furthermore, toluidine blue staining analysis, a method used to specifically identify mast cells, showed that master cell infiltration into the dermis of the GGB-1-treated group was significantly decreased. The immunoglobulin E concentration was lower in the GGB-1-treated group. In addition, the levels of inflammatory cytokines (interferon-${\gamma}$, interleukin-1, 4, 5, 6, and 13, $1{\beta}$, and tumor necrosis factor-${\alpha}$) were also significantly reduced in the GGB-1-treated group. Taken together, these results suggest that a mixture of GS, GC, and BSP in a proportion of 3:1:1 (GGB-1) may contribute to the relief of AD symptoms and may be considered an excellent candidate for an AD therapeutic drug.

Anti-aging and Anti-diabetes Effects of Aconitum pesudo-laeve var. erectum Extracts (진범(Aconitum pesudo-laeve var. erectum) 추출물의 항노화 및 항당뇨 효과)

  • Kim, Jeung-Hoan;Lee, Soo-Yeon;Kwon, O-Jun;Park, Joo-Hoon;Lee, Jin-Young
    • Journal of Life Science
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    • v.23 no.5
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    • pp.616-621
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    • 2013
  • Aconitum pesudo-laeve var erectum has been known to possess anti-inflammatory activity and modulate the intestinal immune system. In addition, it has traditionally been used for the treatment of water retention in the body. In this study, the anti-aging and anti-diabetes effects of water and ethanol extracts from Aconitum pesudo-laeve var. erectum were investigated. The activities of each extract were measured by antioxidant tests such as DPPH and ABTS radical scavenging activity, antioxidant protection factor (PF), TBARs content, and ${\alpha}$-amylase and ${\alpha}$-glucosidase inhibition activity assay. DPPH radical scavenging activity was found in over 50% of water and ethanol extracts at $100{\mu}g/ml$, $50{\mu}g/ml$, respectively. The ABTS radical scavenging activity of ethanol extract was $99.8{\pm}0.1$% at $1,000{\mu}g/ml$ in water, which was highest among the ethanol extract concentrations. PFs measured with ${\beta}$-carotene-linoleate model systems were in the order of ethanol (1.49 PF at $1,000{\mu}g/ml$) > ethanol (1.40 PF at $500{\mu}g/ml$) > water (1.33 PF at $1,000{\mu}g/ml$) > water (1.27 PF at $500{\mu}g/ml$). TBARs content in ethanol extracts ($1,000{\mu}g/ml$) was $0.16{\pm}0.03{\mu}M$, which was lower than that of water extracts and other ethanol extract concentrations. The extracts also showed over 90% of ${\alpha}$-amylase inhibition and over 60% of ${\alpha}$-glucosidase inhibition ratio in water ($1,000{\mu}g/ml$) and ethanol extracts (100~$1,000{\mu}g/ml$). These results suggest that Aconitum pesudo-laeve var. erectum extracts could be used as a cosmetic source and preventive agent for aging and diabetes.

A Study on Comparative Analysis of Socio-economic Impact Assessment Methods on Climate Change and Necessity of Application for Water Management (기후변화 대응을 위한 발전소 온배수 활용 양식업 경제성 분석)

  • Lee, Sangsin;Kim, Shang Moon;Um, Gi Jeung
    • Journal of Korean Society of societal Security
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    • v.4 no.2
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    • pp.73-78
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    • 2011
  • In order to resolve the problem of change in global climate which is worsening as days go by and to preemptively cope with strengthened restriction on carbon emission, the government enacted 'Framework Act on Low Carbon Green Growth' in 2010 and selected green technology and green industry as new national growth engines. For this reason, the necessity to use the un-utilized waste heat across the whole industrial system has become an issue, and studies on and applications of recycling in the agricultural and fishery fields such as cultivation of tropical crops and flatfishes by utilizing the waste heat and thermal effluent generated by large industrial complexes including power plants are being actively carried out. In this study, we looked into the domestic and overseas examples of having utilized waste heat abandoned in the form of power plant thermal effluent, and carried out economic efficiency evaluation of sturgeon aquaculture utilizing thermal effluent of Yeongwol LNG Combined Cycle Power Plant in Gangwon-do. In this analysis, we analyzed the economic efficiency of a model business plan divided into three steps, starting from a small scale in order to minimize the investment risk and financial burden, which is then gradually expanded. The business operation period was assumed to be 10 years (2012~2021), and the NVP (Net Present Value) and economic efficiency (B/C) for the operation period (10 years) were estimated for different loan size by dividing the size of external loan by stage into 80% and 40% based on the basic statistics secured through a site survey. Through the result of analysis, we can see that reducing the size of the external loan is an important factor in securing greater economic efficiency as, while the B/C is 1.79 in the case the external loan is 80% of the total investment, it is presumed to be improved to 1.81 when the loan is 40%. As the findings of this study showed that the economic efficiency of sturgeon aquaculture utilizing thermal effluent of power plant can be secured, it is presumed that regional development project items with high added value can be derived though this, and, in addition, this study will greatly contribute to reinforcement of the capability of local governments to cope with climate change.

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Analysis of Prognostic Factors in Glioblastoma Multiforme (다형성 교모세포증 환자의 예후인자 분석)

  • Chang Sei Kyung;Suh Chang Ok;Lee Sang Wook;Keum Ki Chang;Kim Gwi Eon;Kim Woo Cheol
    • Radiation Oncology Journal
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    • v.14 no.3
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    • pp.181-189
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    • 1996
  • Purpose : To find the more effective treatment methods that improving the survival of patients with glioblastoma multiforme(GBM), we analyze the prognostic factors and the outcome of therapy in patients with GBM. Materials and Methods : One hundred twently-one patients with a diagnosis of GBM treated at Severance Hospital between 1973 and 1993 were analyzed for survival with respect to patients characteristics, that is, duration of symptom, age, and Karnofsky performance status, as well as treatment related variables such as extent of surgery and radiotherapy. Results : The median survival time(MST) and 2-year overall survival rate (OSR) of the patients with GBM were 13 months and $20.8\%$, respectively. Duration of symptom, age, Karnofsky performance status(KPS), radiotherapy, and extent of surgical resection were associated with improved survial in a univariate analysis. Patients whose duration of symptom was longer than 3 months, had the 2-year OSR of $47.2\%$(p=0.0082), who were younger than age 50, $32.9\%$(p=0.0003) In patients with a KPS of 80 or higher, the 2-rear OSR was $36.9\%$(p=0.0422). Patients undergoing radiotherapy had the 2-year OSR of $22.9\%$(p=0.0030), and surgical resection of $23.3\%$ (p<0.000). A Cox regression model confirmed a significant correlation of duration of symptom, age, radiotherapy, and extent of surgical resection with survival, excluding KPS(P=0.8823). The 2-year OSR were $22.3\%$ and $19.4\%$, combined with chemotherapy or without, respectively(p=0.6028). The duration of symptom of 3 months or shorter, 50 years of age or older, and undergoing stereotactic biopsy only were considered as risk factors, then patients without any risk factors had the MST of 29 months and 2-year OSR of $53.9\%$ compared to 4 months and $0\%$ for Patients who had all 3 risk factors. Most of all treatment failures occurred in the primary tumor site($80.4\%$). Conclusion : The duration of symptom, age, radiotherapy, and extent of surgical resection were a prognostically significant indeuendent variables. To get a better survival, it seems to be reasonable that the study design which improves the local control rates is warranted.

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Prognostic Factors for Local Control in Early Glottic Cancer Treated with Radiation Therapy (방사선치료를 받은 조기 성문암 환자의 국소 종양 제어에 관한 예후 인자)

  • Chung Woong-Ki;Ahn Sung Ja;Nam Taek Keun;Nah Byung Sik;Cho Jae-Shik;Lim Sang-Chull
    • Radiation Oncology Journal
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    • v.18 no.4
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    • pp.226-232
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    • 2000
  • Purpose :This study was performed to find out the prognostic factors affecting local control in early glottic cancer treated with radiation therapy alone. Materials and Methods :We analysed 37 patients of histologically confirmed early glottic cancer treated at Chonnam National University Hospital between July Im and December 1995, retrospectively. Age of patients ranged from 30 to 73 years (median; 59 years). Thirty-five (95$\%$) patients were male. Histological type was all squamous cell carcinoma. According to the staging system of 1997 American Joint Committee on Cancer, 37 patients were restaged as follows: Tla; U (73$\%$), Tlb; 3 (8$\%$), 72: 7 (19$\%$). Radiation therapy was done using 6 MV X-ray of linear accelerator The range of total radiation dose delivered to the glottic lesion was between 5,040 cGy and 7,020 cGy (median; 6,600 cGy). Median follow-up period was U months. local control rates were calculated by Kaplan-Meier method. Generalized Wilcoxon test was used to evaluate the difference of control rates between comparable groups. Multivariate analysis using Cox proportional hazard model was done to find out prognostic factors affecting local control. Results:5 year survival rate of 37 patients was 89$\%$. Local control rate of 37 patients was 74$\%$ in 5 years. We included age, 7-stage, anterior commissure involvement, fraction size, total radiation dose, treatment time of radiotherapy as potential prognostic factors in univariate and multivariate analysis. As a result, treatment time had statistical significance in local control rate in both univariate (p=0.026) and multivariate (p=0.017) analysis. Complication was not recorded except one patient with hypothyroidism. Conclusion :This study revealed that overall treatment time of radiation was a significant factor affecting local control rate.

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Postoperative Radiotherapy in Malignant Tumors of the Parotid Gland (이하선 악성종양의 수술 후 방사선 치료)

  • Chung Woong-Ki;Ahn Sung Ja;Nam Taek Ken;Chung Kyung-Ae;Nah Byung Sik
    • Radiation Oncology Journal
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    • v.16 no.3
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    • pp.251-258
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    • 1998
  • Purpose : This study was performed to analyze the factors affecting local control in malignant tumors of the parotid gland treated with surgery and postoperative radiation. Materials and methods : Twenty-six patients were treated for malignant tumors of the parotid gland from 1986 to 1995 at Department of Therapeutic Radiology, Chonnam University Hospital. Age of the patients ranged from 14 to 72 years (median : 55 years). Histologically 10 patients of mucoepidermoid carcinoma, 7 of squamous cell carcinoma, 4 of acinic cell carcinoma, 4 of adenoid cystic carcinoma and 1 of adenocarcinoma were treated. Total parotidectomy was performd in 15 of 26 patients, superficial in 7, subtotal in 4. Facial nerve was sacrificed in 5 patients. Postoperatively 4 patients had residual disease, 4 had positive resection margin. Radiation was delivered through an ipsilateral wedged pair of photon in 11 patients. High energy electron beam was mixed with photon in 15 patients. Electron beam dose ranged from 900 cGy to 3800 cGy (median 1700 cGy). Total radiation dose ranged from 5000 cGy to 7560 cGy (median : 6020 cGy). Minimum follow-up period was 2 years. Local control and survival rate were calculated using Kaplan-Meier method. Generalized Wilcoxon test and Cox proportional hazard model were used to test factors affecting local control. Results : Five (19$\%$) of 26 patients had local recurrence. Five year local control rate was 77$\%$. Overall five year survival rate was 70$\%$. Sex, age, tumor size, surgical involvement of cervical lymph node, involvement of resection margin, surgical invasion of nerve, and total dose were analyzed as suggested factors affecting local control rate. Among them patients with tumor size less than 4 cm (p=0.002) and negative resection margin (p=0.011) were associated with better local control rates in univariate analysis. Multivariate analysis showed only tumor size factor is associated with local control rate (p=0.022). Conclusion : This study suggested that tumor size is important in local control of malignant tumors of parotid gland.

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Reliability Analysis on Firewater Supply Facilities based on the Probability Theory with Considering Common Cause Failures (소방수 공급설비에 대한 공통원인고장을 고려한 확률론적 신뢰도 분석)

  • Ko, Jae-Sun;Kim, Hyo
    • Fire Science and Engineering
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    • v.17 no.4
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    • pp.76-85
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    • 2003
  • In this study, we write down the definitions, their causes and the techniques of analysis as a theoretical consideration of common cause failures, and investigate the limitation and the importance of the common cause failures by applying to the analysis on the fire protection as a representative safety facility. As you can know in the reliability analysis, most impressive cause is the malfunctions of pumping operations; especially the common cause failure of two pumps is dominant. In other words, it is possible to assess system-reliability as twice as actual without CCF From these, CCF is extraordinarily important and the results are highly dependent on the CCF factor. And although it would increase with multiple installations, the reliability are not defined as linear with those multiplications. In addition, the differences in results due to the models for analysis are not significant, whereas the various sources of data produce highly different results. Therefore, we conclude that the reliabilities are dependent on the quality of the usable data much better than the variety of models. As a result, the basic and engineering device for the preventions of CCF of the multiple facilities is to design it as reliably as to design the fire-water pump. That is to say, we must assess those reliabilities using PFD whether they are appropriate to SIL (Safety Integrity Level) which is required for the reliability in SIS (Safety Instrumented System). The result of the analysis on the reliability of the fire-water supply with CCF shows that PFD is 3.80E-3, so that it cannot be said to be designed as safely as in the level of SIL5. However, without CCF, PFD is 1.82E-3 which means that they are designed as unsafely as before.