• Journal of Advanced Navigation Technology
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• v.28 no.3
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• pp.272-277
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• 2024

In most countries, instrument flight procedures are designed by applying one of the following standards: the International Aviation Organization's DOC 8168, Air Navigation Services and Operation Procedures (PANS-OPS), or the US Federal Aviation Administration's TERPS, Terminal Procedures. In particular, the circling approach procedure has many differences between the two standards, and the US terminal procedure (TERPS) has become more complicated since 2013 by applying expanded standards depending on altitude. The circling approach procedures are more risky than straight-in approach procedures because it involves maneuvering the aircraft close to the ground at low energy for landing. In order to accurately understand these differences, this study provides to distinguish by what criteria the circling approach procedure is designed according to individual domestic airports in Korea, to calculate the radius for the range of circling approach areas that guarantee minimum obstacle avoidance during circling approach maneuvers, and to present methods for performing safe circling approach procedures.

• Journal of Chest Surgery
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• v.37 no.7
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• pp.559-569
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• 2004

The CarboMedics mechanical valve has been reported to show acceptable valve-related complication rates. The aim of this study is to evaluate our clinical experience with the CarboMedics valve. Material and Method: Between August 1988 and September 1999, we implanted 1,144 CarboMedics valves in 850 patients (aortic 179; mitral 385; double-valve 234; tricuspid 52). The mean age was 44.5 $\pm$ 12.5 years. Follow-up was completed in 95.2% and median follow-up period was 7.9 years (6753 patient-years). Result: The overall hospital mortality rate was 3.4% and the mortality rate for each group was 1.7% for aortic group, 2.6% for mitral group, 4.7% for double-valve group, and 9.6% for tricuspid group, Tricuspid group showed significantly higher mortality rate than aortic and mitral group (p〈0.05). The actuarial survival at 10 years was 87.1 $\pm$ 2.6%, 88.9 $\pm$ 1.7%, 82.4 $\pm$ 2.9%, and 77.5 $\pm$ 7.0% for aortic, mitral, double, and tricuspid valve group, respectively. Age and tricuspid valve replacement were significant risk factors for long-term survival in multivariate analysis (p 〈 0.05). Freedom from valve thrombosis at 10 years was 99.4 $\pm$ 0.6%, 98.2 $\pm$ 0.8%, 99.2 $\pm$ 0.8%, and 87.6 $\pm$ 0.5% for aortic, mitral, double and tricuspid valve group. Tricuspid valve group showed significantly higher rate of valve thrombosis (p 〈 0.05). Conclusion: Long-term results of our experience demonstrated that CarboMedics valve showed acceptable incidence of valve-related complications. However, tricuspid valve replacement showed higher rate of early mortality and valve thrombosis than other valve replacement groups.

• The Journal of the Korea Contents Association
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• v.18 no.7
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• pp.536-550
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• 2018

This paper examine how acceptance of AI robots can be achieved according to occupational groups when the discourse on human labor and occupation changes due to the new industrial revolution is spreading steadily. Previous research on the acceptance of new technologies and products has predicted use behavior through subjective beliefs and values that do not change well over the short term. Therefore, this study compares the beliefs, values, and use intention of AI robots according to occupation. As a result, the subjective belief factor for AI robots was classified into belief in rationality(reason) and belief in benevolence(emotion). The value factors were divided into acceptance value(role performance, communication, social comparison) and avoidance value(risk, complexity). There was a significant difference in the effect of these on the use intention of AI robot by occupation and employment types. This result suggests that there are gaps in the occupation group at the rate of technology acceptance, as opposed to the existing prediction that AI robots will be rapidly expanded by professionals.

• The Korean Journal of Financial Management
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• v.26 no.1
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• pp.165-188
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• 2009

This paper has suggested the methodology for the frontier portfolios and the optimal portfolio under the mean-VaR framework, not assuming the normal distribution and considering the investor's preferences for the higher moments of return distributions. It suggested the grid and rank approach which did not need an assumption about return distributions to find the frontier portfolios. And the optimal portfolio was selected using the utility function that considered the 3rd and the 4th moments. For the application of the methodology, weekly returns of the developed countries index, the emerging market index and the KOSPI index were used. After the frontier portfolios of the mean-variance framework and the mean-VaR framework were selected, the optimal portfolios of each framework were compared. This application compared not only the difference of the standard deviation but also the difference of the utility level and the certainty equivalent expressed by weekly expected returns. In order to verify statistical significances about the differences between the mean-VaR and the mean-variance, this paper presented the statistics which were obtained by the historical simulation method using the bootstrapping. The results showed that an investor under the mean-VaR framework had a tendency to select the optimal portfolio which has bigger standard deviation, comparing to an investor under the mean-variance framework. In addition, the more risk averse an investor is, the bigger utility level and certainty equivalent he achieves under the mean-VaR framework. However, the difference between the two frameworks were not significant in statistical as well as economic criterion.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.9
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• pp.1788-1795
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• 2017

In this paper, we proposed a service that provides CPA/TCPA information to ships, without ARPA/ATA devices to support decision making of the navigator for maritime safety based on various services at shore and off-shore. To verify the proposed service, we use SiNAS (scenario-based simulator for NAS) with CPA/TCPA information providing software to evaluate its usability, because executing the test in real ship has many limitations and difficulties. To do this, we specify two simulation scenarios for the required purpose, and we liaise twelve participants with various navigation experience to conduct the simulations. Also, we analyze the results of simulation using mission success or not, the minimum approaching distance with the target ship, the time of a recognition the target ship, the time of a first action for collision avoidance with the target ship, and so on. Then, we evaluate usability of the proposed service based on the three elements which are effectiveness, efficiency and satisfaction.

• International Commerce and Information Review
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• v.18 no.1
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• pp.55-78
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• 2016

This paper discusses on Electronic Payment System between U.S.A. and Canada. In particular, I focused on ACSS compare with FedACH(Fed Automated Clearing House) to advance a research effects. Because both of them is a low-value, high-volume retail payment system which their countries represent. The ACSS(Automated Clearing Settlement System) is the system through which the vast majority of CPA payment items are cleared, through various payment streams. In 2014, ACSS system cleared approximately 6.8billion payments worth a total value of $ 44.9 trillion. While, The FedACH Network are the center of America Commerce, moving more than $40 trillion each year. That's made up of almost 23 billion electronic financial transaction, including direct deposit via ACH, social security and government benefits, electronic bill payments such as utility and mortgage payments. Thus in this article, first of all, I considered features of payment system and the types of payment items between ACSS and FedAch. Second, I analyzed the status of central bank and legal background. Third, I focused on the operational policy and risk aversion policy. Lastly, I suggested that their payment and banking system have to assume, with good reason, more efficiently accurately and securely operation to protect their customer from credit risk and financial fraud.

• The Journal of the Korea Contents Association
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• v.17 no.5
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• pp.8-17
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• 2017

Using 1855 observations from 5 years-371 firms panel data during 2010 to 2014 in Chinese stock exchanges, this study examines the impact of managers' ownership on R & D expenditures. The empirical study finds that when firms are state-owned, managers' ownership have negative relation with the level of R & D expenses as well as the likelihood of executing R & D investment, implying that managers are less likely to invest in high risky projects due to managerial ownership's entrenchment effects to pursue private benefits rather than alignment of interest effect as shareholders. The empirical study also finds that when firms are private-owned, managerial ownership are inverse U shaped related to the level of R & D expenses, implying that managers are less likely to invest in high risky projects due to increasing risk aversion resulting from concentration of private wealth at its high level while managers are more likely to invest in high risky projects due to increasing incentives as shareholders at its low level. The results support that the effects of managerial ownership on R & D expenses may be different according to the ownership type of Chinese listed firms.

• The Journal of the Korea Contents Association
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• v.22 no.3
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• pp.165-178
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• 2022

In this study, to explore the psychological and biosocial characteristics of the temperament and character's latent profile group, first, the latent group was identified with the seven variables of the Temperament and Character Inventory(TCI), and second, the difference between the psychological and biosocial characteristics of three identified latent groups. A total of 287 university students participated, and the latent groups was identified through latent profile analysis, a human-centeted statistical method, using Cloninger's TCI, Cognitive Emotion Regulation Questionnaire(CERQ), Positive Affect and Negative Affect Schedule(PANAS), Composite Scale of Moriningness(CSM), Pittsburgh Sleep Qulity Index(PSQI), and Satisfaction With Life Scale(SWLS). As result, first, three latent groups were identified through latent profile analysis using the seven variables of TCI. second, significant differences were identified in CERQ, PANAS, which are psychological variables, CSM, PSQI, and SWLS, which are biosocial variables among the latent groups. In conclusion, the importance of Self-Directedness(SD), a character factor that can be developed rather than Harm-Avoidance(HA), a temperament factor from nature, was confirmed. And the necessity of follow-up studies on psychological and biosocial variables for adaptive and mature personality was discussed.

• Journal of Advanced Navigation Technology
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• v.26 no.5
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• pp.304-311
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• 2022

Although the SEAD(suppression to enemy air defenses) mission is a strategically important task in modern warfare, the high risk of direct exposure to enemy air defense assets forces to use of unmanned aerial vehicles. this paper proposes a path planning algorithm for SEAD mission for an unmanned aerial vehicle and a method for calculating the mission effectiveness on the planned path. Based on the RRT-based path planning algorithm, a low-altitude ingress/egress flight path that can consider the enemy's short-range air defense threat was generated. The Dubins path-based Intercept path planning technique was used to generate a path that is the shortest path while avoiding the enemy's short-range anti-aircraft threat as much as possible. The ingress/intercept/egress paths were connected in order. In addition, mission effectiveness consisting of fuel consumption, the survival probability, the time required to perform the mission, and the target destruction probability was calculated based on the generated path. The proposed techniques were verified through a scenario.

• Journal of Industrial Convergence
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• v.21 no.1
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• pp.175-185
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• 2023

Recently, novel viral infections such as COVID-19 have spread and pose a serious public health problem. In particular, these diseases have a fatal effect on the elderly, threatening life and causing serious social and economic losses. Accordingly, applications such as telemedicine, healthcare, and disease prevention using the Internet of Things (IoT) and artificial intelligence (AI) have been introduced in many industries to improve disease detection, monitoring, and quarantine performance. However, since existing technologies are not applied quickly and comprehensively to the sudden emergence of infectious diseases, they have not been able to prevent large-scale infection and the nationwide spread of infectious diseases in society. Therefore, in this paper, we try to predict the spread of infection by collecting various infection information with regional limitations through a virus disease information collector and performing AI analysis and severity matching through an AI broker. Finally, through the Korea Centers for Disease Control and Prevention, danger alerts are issued to the elderly, messages are sent to block the spread, and information on evacuation from infected areas is quickly provided. A realistic elderly support system compares the location information of the elderly with the information of the infected area and provides an intuitive danger area (infected area) avoidance function with an augmented reality-based smartphone application. When the elderly visit an infected area is confirmed, quarantine management services are provided automatically. In the future, the proposed system can be used as a method of preventing a crushing accident due to sudden crowd concentration in advance by identifying the location-based user density.