• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.640-648
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• 2022

In the United States, the Safety Rest Areas (SRAs) were introduced as highway roadside infrastructures in the early 1900s. The State Departments of Transportation (DOTs) operate/maintain their SRAs using different methods. The Washington DOT used the in-house workforce method for over 20 years, whereas some states moved to Performance-Based Contracting (PBC) from the in-house workforce to save cost primarily. Several existing studies claimed that using the PBC approach saved costs on several highway assets. Thus, the principal objective of this study is to compute and compare the unit operating/maintenance cost of SRAs using the in-house workforce method (in Washington state) with the PBC approach (in other states). The findings of this study show that the average annual cost using the PBC approach was much more than the average annual cost using the in-house workforce approach. The findings also show that in Washington state, the 'Labor Cost' category was a key expenditure, which is statistically higher than other categories. The 'Labor Cost' was followed by the 'Other Services', and then 'Materials and Supplies' and 'Equipment.' The study's findings indicated that outsourcing does not always save costs for agencies. The study findings may help transportation construction/maintenance professionals select a cost-effective approach for their future planning.

• 한국콘텐츠학회논문지
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• 제20권9호
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• pp.271-284
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• 2020

하프라이프 알릭스에 대한 시장의 호평과 VR장비 판매 증가는 수익모델의 부재로 미래가 불확실한 VR시장 활성화의 전환점이 될 수 있다. 이에 선행연구를 바탕으로 VR게임의 특성을 그래픽, 1인칭시스템, 인터페이스, 컨트롤러, 인터랙션 기술, 사운드, 스토리로 분류하고 분석하였다. 분석결과 7개 요소는 VR의 구성 요소 중 게임의 완성도를 의미하는 '상호작용'과 '가상이미지'에 해당하였으며 상호 연결되어 있어 이를 묶은 상위 개념인 '현존감'을 제안하였다. VR 구성요소로서 사용자의 감정을 나타내는 '몰입감'은 유저의 능력에 적절한 과제의 난이도를 부여하는 몰입이론으로 분석하였으며 연구 과정은 전문가 패널 15명에게 델파이 기법과 FGI를 실시하여 객관성 확보를 위해 노력하였다. 마지막으로 '현존감'과 '몰입감'은 비례하는 특성으로서 알릭스는 물론 앞으로 VR게임 분석에서도 계속 유효한 개념이 될 수 있으므로 두 단어를 합한 '프레즌스 이펙트'라는 개념적인 틀을 제안하였다.

• Journal of Dental Anesthesia and Pain Medicine
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• 제18권1호
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• pp.47-56
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• 2018

Background: The purpose of this study is to investigate the effects of administration order when a sedative drug (midazolam) and an opioid analgesic drug (fentanyl) is applied for moderate intravenous (IV) sedation in dentistry. Methods: A retrospective chart review was conducted in one dental clinic during its transition from a midazolam-first to a fentanyl-first protocol for dental procedures requiring moderate IV sedation. Physiological parameters, drug administration times, patient recovery times, drug dosages, and patient recall and satisfaction were investigated for differences. Results: A total of 76 charts (40 midazolam-first and 36 fentanyl-first administrations), were used in the analysis. Administering midazolam first resulted in an average 4.38 min (52%) decrease in administration times (P < 0.001), and a decrease in procedural recollection immediately following the procedure (P = 0.03), and 24 to 48 hours later (P = 0.009). Administering fentanyl first required an average of 2.43 mg (29%) less midazolam (P < 0.001). No significant differences were found for change in vital signs, minimum oxygen saturation levels, recovery times, and patient satisfaction (P > 0.05). Oxygen saturation levels did not drop below 90% for either group; however, 5 cases in the fentanyl-first group fell to between 90% and 92%, compared with 0 cases in the midazolam-first group. Conclusions: The administration order of fentanyl and midazolam may have different effects on patients and the sedation procedure. Findings from this study should be used to facilitate discussion among dental practitioners and to guide additional research investigating this topic.

• The Journal of Advanced Prosthodontics
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• 제8권1호
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• pp.53-61
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• 2016

PURPOSE. This study conducted an analysis of cost-effectiveness of the implant and conventional fixed dental prosthesis (CFDP) from a single treatment perspective. MATERIALS AND METHODS. The Markov model for cost-effectiveness analysis of the implant and CFDP was carried out over maximum 50 years. The probabilistic sensitivity analysis was performed by the 10,000 Monte-Carlo simulations, and cost-effectiveness acceptability curves (CEAC) were also presented. The results from meta-analysis studies were used to determine the survival rates and complication rates of the implant and CFDP. Data regarding the cost of each treatment method were collected from University Dental Hospital and Statistics Korea for 2013. Using the results of the patient satisfaction survey study, quality-adjusted prosthesis year (QAPY) of the implant and CFDP strategy was evaluated with annual discount rate. RESULTS. When only the direct cost was considered, implants were more cost-effective when the willingness to pay (WTP) was more than 10,000 won at $10^{th}$ year after the treatment, and more cost-effective regardless of the WTP from $20^{th}$ year after the prosthodontic treatment. When the indirect cost was added to the direct cost, implants were more cost-effective only when the WTP was more than 75,000 won at the $10^{th}$ year after the prosthodontic treatment, more than 35,000 won at the $20^{th}$ year after prosthodontic treatment. CONCLUSION. The CFDP was more cost-effective unless the WTP was more than 75,000 won at the $10^{th}$ year after prosthodontic treatment. But the cost-effectivenss tendency changed from CFDP to implant as time passed.

• International Journal of Oral Biology
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• 제48권1호
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• pp.1-7
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• 2023

Oral squamous cell carcinoma (OSCC), which accounts for approximately 90% of oral cancers, has a high rate of local recurrence and a poor prognosis despite improvements in treatment. Exosomes released from OSCC cells promote cell proliferation and metastasis. Although it is clear that the biogenesis of exosomes is mediated by the endosomal sorting complex required for transport (ESCRT) machinery, the gene expression pattern of ESCRT, depending on the cell type, remains elusive. The exosomal release from the human OSCC cell lines, HSC-3 and HSC-4, and their corresponding gefitinib-resistant sub-cell lines, HSC-3/GR and HSC-4/GR, was assessed by western blot and flow cytometry. The levels of ESCRT machinery proteins, including Hrs, Tsg101, and Alix, and whole-cell ubiquitination were evaluated by western blot. We observed that the basal level of exosomal release was higher in HSC-3/GR and HSC-4/GR cells than in HSC-3 and HSC-4 cells, respectively. Long-term gefitinib exposure of each cell line and its corresponding gefitinib-resistant sub-cell line differentially induced the expression of the ESCRT machinery. Furthermore, whole-cell ubiquitination and autophagic flux were shown to be increased in gefitinib-treated HSC-3 and HSC-4 cells. Our data indicate that the expression patterns of the ESCRT machinery genes are differentially regulated by the characteristics of cells, such as intracellular energy metabolism. Therefore, the expression patterns of the ESCRT machinery should be considered as a key factor to improve the treatment strategy for OSCC.