• Journal of Korean Neurosurgical Society
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• v.66 no.3
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• pp.247-257
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• 2023

Recently, the survival of the high-risk population of preterm infants has steadily improved, and the severity of prematurity is a growing threat of gestational-age-related fatal conditions. Posthemorrhagic hydrocephalus (PHH) is the most common but serious neurological complication in premature infants, which can have life-threatening consequences during the acute phase in the neonatal period and life-long psychomotor and cognitive sequelae in their later life. Although neonatologists, pediatric neurologists, and pediatric neurosurgeons have investigated a diversified strategy for several decades, a consensus on the best management of PHH in premature infants still must be reached. Several approaches have tried to reduce the incidence of intraventricular hemorrhage (IVH) and mitigate the effect of IVH-related hydrocephalus. This paper reviews and discusses the clinical feature of PHH in premature infants, general/nonsurgical management of prematurity for IVH prevention, and posthemorrhagic management, and how and when to intervene.

• Current Optics and Photonics
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• v.7 no.1
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• pp.28-32
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• 2023

Frequency characteristics of gain-saturated erbium-doped fiber amplifier (EDFA) are experimentally evaluated to mitigate the optical signal fluctuation induced by atmospheric turbulence in terrestrial freespace optical communication systems. Here, an acousto-optic modulator (AOM) is used to emulate optical signal fluctuations induced by atmospheric turbulence. The waveform which is generated in proportion to the refractive-index structural parameters is used to drive the AOM at various periodic frequencies. Thus, the dependence of the signal fluctuation suppression on the frequency is evaluated. The experiment is conducted using a periodic frequency sweep of the AOM driving voltage waveform and signal input power variation of the amplifier. It is observed that a low periodic frequency and high input signal power effectively suppress the optical signal fluctuation. This study evaluates the experimental results from the high-pass filter and gain-saturation characteristics of the EDFA.

• The Journal of Korea Robotics Society
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• v.18 no.2
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• pp.203-215
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• 2023

Social robots, which are mainly used by individuals, emphasize the importance of human-robot relationships (HRR) more compared to other types of robots. Emotional expression in robots is one of the key factors that imbue HRR with value; emotions are mainly expressed through the face. However, because of cultural and preference differences, the desired robot facial expressions differ subtly depending on the user. It was expected that a robot facial expression customization tool may mitigate such difficulties and consequently improve HRR. To prove this, we created a robot facial expression customization tool and a prototype robot. We implemented a suitable emotion engine for generating robot facial expressions in a dynamic human-robot interaction setting. We conducted experiments and the users agreed that the availability of a customized version of the robot has a more positive effect on HRR than a predefined version of the robot. Moreover, we suggest recommendations for future improvements of the customization process of robot facial expression.

• International Journal of High-Rise Buildings
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• v.10 no.2
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• pp.117-121
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• 2021

In 2016, an innovative liquid damper system was installed on the roof of a 35-story modular building in Brooklyn, NY to mitigate wind-induced movement of the structure. The new damper presented several advantages over traditional pendulum, liquid column or sloshing dampers, including lower fabrication and maintenance costs, modularity, and the flexibility to be tuned to a wider range of frequencies. The performance of the system was monitored on a regular basis over the past four years and found adequate, with only minor re-tuning and maintenance operations needed. Based on the experience and data gained through this project, a second iteration of the damper was developed. Called Hummingbird, the improved system further mitigates maintenance and tuning concerns, while allowing significant space savings.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.5
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• pp.1471-1483
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• 2023

One of the fastest-growing mobile services accessible today is mobile payments. For the safety of this service, the Near Field Communication (NFC) technology is used. However, NFC standard protocol has prioritized transmission rate over authentication feature due to the proximity of communicated devices. Unfortunately, an adversary can exploit this vulnerability with an antenna that can eavesdrop or alter the exchanged messages between NFC-enabled devices. Many researchers have proposed authentication methods for NFC connections to mitigate this challenge. However, the security and privacy of payment transactions remain insufficient. We offer a privacy-preserving, anonymity-based, safe, and efficient authentication protocol to protect users from tracking and replay attacks to guarantee secure transactions. To improve transaction security and, more importantly, to make our protocol lightweight while ensuring privacy, the proposed protocol employs a secure offline session key generation mechanism. Formal security verification is performed to assess the proposed protocol's security strength. When comparing the performance of current protocols, the suggested protocol outperforms the others.

• Journal of the Korea Institute of Building Construction
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• v.23 no.4
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• pp.485-496
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• 2023

Precise construction cost estimation is paramount to determining the total construction expense of a project prior to the initiation of the construction phase. Despite this, manual quantification and cost estimation methods, which continue to be widely used, may result in imprecise estimation and subsequent financial loss. Given the fast-paced and efficiency-demanding nature of the construction industry, trustworthy quantity and cost estimation is essential. To mitigate these obstacles, this research is focused on establishing an automated quantity estimation algorithm, particularly designed for the main rebar of beams which are recognized for their complicated reinforcement configurations. The exact quantity derived from the proposed algorithm is compared to the manually approximated quantity, reflecting a variance of 10.27%. As a result, significant errors and impending financial loss can be averted. The implementation of the findings from this research holds the potential to significantly assist construction firms in quickly and accurately estimating rebar quantities while adhering strictly to applicable specifications and regulatory requirements.

• Journal of the Korea Safety Management & Science
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• v.25 no.2
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• pp.91-97
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• 2023

Ensuring the safe arrival of delivery cargo at its intended destination is of utmost importance. Truck drivers play a crucial role in guaranteeing the secure delivery of cargo without any mishaps. However, there are various factors that may lead to delayed arrival of trucks at their destination, such as late departures or prolonged loading operations. The timely departure of cargo transportation is contingent upon several variables, including the driver's experience, cargo volume, and loading time. If the transportation commencement is delayed, it may increase the risk of accidents due to an elevated operating speed. Consequently, we conducted a study to investigate the correlation between cargo loading time, cargo volume, driving experience, and the likelihood of accidents. Our findings indicate that both cargo volume and driver experience can impact the likelihood of vehicle accidents. Furthermore, all factors can have an interactive effect on the occurrence of accidents. However, extending the loading time may mitigate the impact on the likelihood of accidents.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.332-333
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• 2020

본 논문에서는 태양광 출력 감발 시 입력 커패시터의 영향을 분석하고, 이를 완화시키는 제어 방법을 제안한다. 기존의 감발 제어는 태양광 시스템 출력에 대한 입력 커패시터의 영향을 고려하지 않아, 출력 감발 시 오히려 태양광 시스템 출력이 순간적으로 증가할 위험이 있다. 따라서 입력 커패시터 출력을 고려한 제어 방법을 제안하여, 순간적인 태양광 시스템 출력 증가를 방지하고 연계된 계통의 안정적인 운영을 가능케 한다.

• Advances in nano research
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• v.15 no.1
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• pp.67-74
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• 2023

The combination of physical activities and individual skills in sports creates an entertaining and competitive environment governed by a set of rules. In today's world, sports attract significant attention and are approached differently by various groups. Inevitably, injuries occur in sports, significantly impacting an athlete's performance and ability to participate in exercises and competitions. Addressing this issue, one of the crucial measures involves restoring the athlete's ability to engage in sports and compete. Sports rehabilitation serves as a treatment to mitigate the effects of injuries, and when combined with surgery, it can expedite the recovery process. Therefore, the primary objective of this study is to utilize a biocompatible technology for synthesizing zinc oxide (ZnO) nanoparticles in sports rehabilitation, ensuring minimal harm to the environment.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.19 no.1
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• pp.36-43
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• 2023

Lots of researches have been conducted on in-vessel retention (IVR) to prevent or mitigate severe accident in nuclear power plants. Various methodologies were proposed and the external reactor vessel cooling was selected as a part of promising IVR strategy. In this study, the strategy is strengthened by enhancing the natural circulation performance through the adoption of insulation in the reactor cavity. A thermal analysis was carried out based on an assumed accident scenario and its results were used as boundary conditions for subsequent seven flow analysis cases. By comparing the natural circulation performance, effects of annular gaps and insulation shapes on the mass flow rate and flow velocity were quantified. The improvement in cooling performance can be reflected in actual design via detailed assessment.