• Journal of Dental Anesthesia and Pain Medicine
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• v.23 no.2
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• pp.69-81
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• 2023

Background: In order to assess the effectiveness of various analgesio-sedative combinations for pain relief and sedation in pediatric dental patients, a thorough evaluation of clinical studies and patient outcomes is necessary. Methods: A total of 128 healthy, uncooperative pediatric dental patients were randomly allocated to receive one of the four combinations of drugs via the intranasal (IN) route: Group I received midazolam-ketamine (MK), Group II received dexmedetomidine-ketamine (DK), Group III received midazolam-fentanyl (MF), and Group IV received dexmedetomidine-fentanyl (DF) in a parallel-arm study design. The efficacy and safety of the combinations were evaluated using different parameters. Results: The onset of sedation was significantly faster in the DF group than in the DK, MF, and MK groups (P < 0.001). The depth of sedation was significantly higher in the DK and DF groups than in the MK and MF groups (P < 0.01). DK and DF produced significant intra- and postoperative analgesia when compared with combinations of MK and MF. No significant adverse events were observed for any of the combinations. Conclusions: The DK and DF groups showed potential as analgesio-sedatives in view of their anxiolytic and analgesic effects.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.3
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• pp.265-274
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• 2022

MSMEs in the food and beverage industry play a critical role in the Indonesian economy since they account for the majority of the manufacturing sector's GDP. Despite its importance, it is unable to compete on a worldwide scale due to a lack of technological adoption. As a result, the purpose of this study is to look into the concerns and challenges that F&B MSMEs have when it comes to technology adoption. An online survey of 626 MSMEs and in-depth interviews as well as focus groups with diverse stakeholders from four provinces, namely West Java, East Java, South Sulawesi, and North Sumatera, provided the data for this study. To be thorough, the approach used in the study is based on the Technology, Organization, and Environment (TOE) framework. According to the findings, the majority of MSMEs use technology for marketing and sales, mainly through e-commerce. Meanwhile, for a variety of reasons, most of them continue to rely on traditional and semi-automatic technologies for production. According to the TOE framework, MSMEs lack those three parts of the technology adoption framework, particularly the environmental aspect, which is mostly due to a lack of cooperation among stakeholders. Finally, as a policy proposal, we offer a comprehensive technology adoption strategy based on the findings through an integrated MSMEs development information system including many important stakeholders.

• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2315-2324
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• 2023

Space nuclear reactors are becoming popular in deep space exploration owing to their advantages of high-power density and stability. Following the fourth-generation nuclear reactor technology, a conceptual design of the dual drum-controlled space molten salt reactor (D²-SMSR) is proposed. The reactor concept uses molten salt as fuel and heat pipes for cooling. A new reactivity control strategy that combines control drums and safety drums was adopted. Critical physical characteristics such as neutron energy spectrum, neutron flux distribution, power distribution and burnup depth were calculated. Flow and heat transfer characteristics such as natural convection, velocity and temperature distribution of the D²-SMSR under low gravity conditions were analyzed. The reactivity control effect of the dual-drums strategy was evaluated. Results showed that the D²-SMSR with a fast spectrum could operate for 10 years at the full power of 40 kWth. The D²-SMSR has a high heat transfer coefficient between molten salt and heat pipe, which means that the core has a good heat-exchange performance. The new reactivity control strategy can achieve shutdown with one safety drum or three control drums, ensuring high-security standards. The present study can provide a theoretical reference for the design of space nuclear reactors.

• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2158-2165
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• 2023

Marine radioactivity monitoring is critical for taking immediate action in case of unexpected nuclear accidents at nuclear facilities located near coastal areas. Especially when the level of contamination is not predictable, mobile monitoring systems will be useful for wide-area ocean radiation survey and for determination of the level of radioactivity. Here, we used a silicon photomultiplier and a high-efficiency GAGG crystal to fabricate a compact, battery-powered gamma spectroscopy that can be used in an ocean environment. The developed spectroscopy has compact dimensions of 6.5 × 6.5× 8 cm³ and weighs 560 g. We used LoRa, a low-power wireless protocol for communication. Successful data transmission was achieved within 1.4 m water depth. The developed gamma spectroscopy was able to detect radioactivity from a ¹³⁷Cs point source (3.7 kBq) at a distance of 20 cm in water. Moreover, we demonstrated an unmanned radioactivity monitoring system in a real sea by combining unmanned surface vehicle with the developed gamma spectroscopy. A hidden ¹³⁷Cs source (3.07 MBq) was detected by the unmanned system at a distance of 3 m. After successfully testing the developed mobile spectroscopy in an ocean environment, we believe that our proposed system will be an effective solution for mobile real-time marine radioactivity monitoring.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.80-80
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• 2021

2020년은 장마와 태풍으로 인해 중부 및 남부지방에 폭우가 발생하여 강남역을 비롯한 지하철 역사와 지하 주차장 등 많은 지하시설이 침수되었고, 부산에서는 침수된 지하차도에 진입한 차량의 운전자가 사망하는 등의 사고가 발생하였다. 지하에 설치된 시설들은 침수가 발생할 경우 대부분 출입구를 통해 유입되는 물을 거슬러 대피해야 하므로 낙상과 그로 인한 익사 등 자칫 큰 인명피해를 초래할 수 있어 특별히 주의할 필요가 있다. 대피 여부를 결정하고 그에 필요한 시간을 계산하기 위해서는 안전하게 대피 가능한 최대수심(한계수심)을 결정하는 것이 필요하다. 현재 한계수심을 제시한 여러 연구가 있지만 대부분 소수의 성인만을 대상으로 한 실험 결과이기 때문에 성별, 연령, 체중 등 다양한 유형의 사람을 고려한 대피방법 제시가 필요하다. 이에 본 연구에서는 실험 참가자의 유형(성별, 연령, 체중, 신장)에 따른 대피시간의 차이를 고려한 한계수심을 제시할 수 있도록 하였다. 총 308명이 실험에 참여하였으며, 이중 남성은 164명, 여성은 144명이었다. 참가자의 연령은 14세부터 75세까지이며, 신장은 최소 145cm에서 최대 187cm, 체중은 35kgf에서 110kgf 범위이다. 대피시간은 물이 흘러 내려오는 5.1m 길이의 계단을, 난간을 잡은 채 거슬러 올라가는 시간으로 설정하였으며, 계단 상층부의 수심이 30cm일 때와 40cm일 때(한계수심 조건), 2회 측정하였다. 또한, 측정이 종료된 후, '안전하게 대피 가능할 것으로 예상되는 수심'을 선택하도록 하여 참가자가 체감한 실험 난이도를 간접적으로 확인하고 향후 연구에 활용할 수 있도록 하였다. 수집된 자료를 분석한 결과 여성의 경우 수심 30cm와 40cm의 평균 대피시간이 4초 정도의 차이가 나타났으나, 남성의 경우 유의미한 차이가 나타나지 않았다. 또한 '안전하게 대피 가능할 것으로 예상되는 수심'에 대한 답변으로 다수가 실험의 최대 수심 조건인 40cm 이상을 선택하였다. 이와 같은 결과를 보아, 실험의 난도가 높지 않았다고 예상할 수 있으며, 그 원인은 참가자의 안전을 고려해 실험 조건을 난간을 잡은 채 보행하도록 설정한 것이 한계수심을 증가시키는 결과를 가져왔다고 볼 수 있다. 유형에 따른 대피시간의 차이를 분석하기 위해서는 실험의 한계수심 조건을 높이거나, 난간을 잡지 않고 보행할 수 있도록 안전장치를 추가하는 등, 실험조건의 변화가 필요할 것으로 판단되며, 추가적으로 난간을 잡은 채 보행하는 것이 한계수심을 얼마나 높일 수 있는지에 대한 검토를 통하여 정량적인 대피가능 시간을 제시할 수 있을 것으로 사료된다.

• Journal of Korean Academy of Rural Health Nursing
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• v.18 no.1
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• pp.57-71
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• 2023

Purpose: This study aims to provide primary data for policy alternatives by identifying the problem of the nursing workforce shortage. Methods: For quantitative data, 446 questionnaires were analyzed. The mean and standard deviation were used for content description. ANOVA analysis and Scheffe? test were used to compare the differences according to the hospital level. For qualitative data, 1:1 in-depth and group interviews were conducted for six participants. Results: The factors nurses prioritized when choosing a workplace were salary, commuting distance, and work-life balance. Clinical nurses cited low wages, heavy workloads, and burnout as the most considerable difficulties in performing their duties. Factors influencing nurse's turnover intention were low wages, unmanageable workload, and rotation to unwanted departments in that order. New nurses tend not to apply to small-medium-sized hospitals, experienced nurses in their 30s-40s leave hospitals due to childcare and shift work difficulties, and nurses in their 50s and older tend to move to nursing homes rather than acute hospital settings. Conclusion: In this study, wage and workload were mentioned as the most critical factors in nurses' workplace selection, job performance difficulties, and turnover intention, so it is necessary to pay attention to this aspect when improving treatment for nurses.

• Coupled systems mechanics
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• v.12 no.3
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• pp.199-220
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• 2023

This article presents a new analytical model to study the effect of porosity on the shear correction factors (SCFs) of functionally graded porous beams (FGPB). For this analysis, uneven and logarithmic-uneven porosity functions are adopted to be distributed through the thickness of the FGP beams. Critical to the application of this theory is a determination of the correction factor, which appears as a coefficient in the expression for the transverse shear stress resultant; to compensate for the assumption that the shear strain is uniform through the depth of the cross-section. Using the energy equivalence principle, a general expression is derived from the static SCFs in FGPB. The resulting expression is consistent with the variationally derived results of Reissner's analysis when the latter are reduced from the two-dimensional case (plate) to the one-dimensional one (beam). A convenient algebraic form of the solution is presented and new study cases are given to illustrate the applicability of the present formulation. Numerical results are presented to illustrate the effect of the porosity distribution on the (SCFs) for various FGPBs. Further, the law of changing the mechanical properties of FG beams without porosity and the SCFare numerically validated by comparison with some available results.

• Geomechanics and Engineering
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• v.34 no.5
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• pp.491-505
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• 2023

The practical usage of underground space and demand for vehicular tunnels necessitate the construction of non-circular wide rectangular tunnels. However, constructing large tunnels in soft clayey soil conditions with no ground improvement can lead to excessive ground deformations and collapse. In recent years, in situ ground improvement techniques such as jet grouting and deep cement mixing are often utilized to perform cement-stabilisation around the tunnel boundary to prevent large deformations and failure. This paper discusses the stability characteristics and failure behaviour of a wide rectangular tunnel in cement-treated soft clays. First, the plane strain finite element model is developed and validated with the results of centrifuge model tests available in the past literature. The critical tunnel support pressures computed from the numerical study are found to be in good agreement with those of centrifuge model tests. The influence of varying strength and thickness of improved soil surround, and cover depth are studied on the stability and failure modes of a rectangular tunnel. It is observed that the failure behaviour of the tunnel in improved soil surround depends on the ratio of the strength of improved soil surround to the strength of surrounding soil, i.e., q_ui/q_us, rather than just q_ui. For low q_ui/q_us ratios,the stability increases with the cover; however, for the high strength improved soil surrounds with q_ui >> q_us, the stability decreases with the cover. The failure chart, modified stability equation, and stability chart are also proposed as preliminary design guidelines for constructing rectangular tunnels in the improved soil surrounded by soft clays.

• Korean Journal of Social Welfare Studies
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• v.44 no.2
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• pp.59-87
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• 2013

The goal of this study is to understand the experiences of emigration to Vietnam for Korean older males through a qualitative case study. The specific research questions are following. Firstly, what do they experience through emigration to Vietnam? Secondly, what are the meanings of emigration to Vietnam for them? Thirdly, what are the contextual meanings of it? To explore these questions, the data were collected through diverse data collection methods including in-depth interviews with seven research participants for eleven months. Each case was carefully examined and summarized in the within-case analysis and major issues appeared in each case were described in the cross-case analysis before the reconstitution of story-telling considering a holistic context on the older males' experiences of emigration to Vietnam. The six integrated themes are 'Motivation and background of immigration', 'Acculturation', 'Social network', 'Meaning of work', 'Family' and 'Spirituality and attitude to the life', 'Perceptions on death'. Finally, the critical results were summarized before indicating limits and implications of this study and then some suggestions for following studies are summarized on the conclusion.

• Educational Technology International
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• v.13 no.2
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• pp.257-281
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• 2012

This study aims to examine individual perceptions and lived experiences of the Net generation of student teachers and the previous generation of teachers about their technology use in education. The participants of this study include 106 pre-service teachers and 50 in-service teachers from one teacher education university in Korea. Employing a mixed methodology, we first empirically examined the participants' perceptions toward multiple variables related to technology use in education, namely (a) past ICT experiences in schools, (b) personal computer use, (c) constructivist belief, (d) computer efficacy, (e) attitude toward computer in education, and (f) prospective computer use. In addition, we conducted face-to-face interviews with selected participants for the in-depth investigation of their lived experiences about technology use, beliefs, and attitude. Results indicate that there are significant differences between in-service and pre-service teachers in their prior experiences with technology in schools. However, the pre-service and in-service teachers did not differ significantly in their beliefs, attitude and other technology-related variables, which may indicate the danger of generational determinism in the Net Generation debate. The analysis of interview narratives revealed two major themes about the interplay of one's agency and structural changes in the participants' lived experiences with technology use in education: (a) transition from negative past experiences to opportunities for positive computer use, and (b) attitudes formation and change through apprenticeship experiences and structural influences. In conclusion, this study suggests that the Net Generation debate should move beyond dichotomous or techno-centric thinking. There is a critical need to pay more attention to develop deeper understandings of the fundamental diversity existing within the generation itself. Implications for teacher education are also discussed.