• Journal of Ecology and Environment
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• v.31 no.2
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• pp.97-105
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• 2008

Subsocial behavior of the genus Cryptocercus cockroaches has been believed as primitive traits of termite eusociality. Thus, it has been believed that understanding Cryptocercus subsociality is a pre-requisite stage to infer evolutionary route of the eusociality in termites. Woodroaches of Cryptocercus are also well known because of its peculiar characteristics including adults living monogamously in pairs, semelparous reproduction, xylophagy, obligatory association between adults and their offspring, slow development, and anal trophallaxis by adults. Based on the previously accumulated data, we try to understand two major components of Cryptocercus life history, development and reproduction. We hypothesize that harsh winter and length of winter might be one of the main causes driving the appearance of the delayed development and semelparous reproduction in Cryptocercus life history.

• Journal of Hydrogen and New Energy
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• v.35 no.1
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• pp.83-89
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• 2024

In order to confirm the safety against vibration of high-pressure fittings for mobile hydrogen charging devices, the natural frequency was confirmed through ANSYS, and vibration data occurring during driving was applied to utilize the vehicle's operating power spectral density data specified in MIL-STD-810H regulations. Fatigue analysis and resonance were confirmed, and as a result, it was confirmed that the sum of the pure phase ratios was less than 1 for the driving history presented in the standard, and there was no risk of resonance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.424-429
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• 2013

The trolley carrying the pod moves along by the airfield runway. The pod through the trolley are subjected to vibration arising from the ground state, the precision optical components in the pod can have a significant impact. The road tests were conducted by using the measurement pod to remove the risk for the project. The measurement pod was composed with the ACRA, sensors, battery. The accelerometers were attached to get the acceleration through the road condition. The PSD envelop was calculated by FFT from the acceleration. The driving safety was proven through comparing the measurement data and MIL-STD-810G specification.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.28-34
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• 2007

In design stage of vehicles, the application of virtual durability analysis techniques enables us to cut down the necessary time and cost to carry out various physical experiments. In this study, computer simulations of vehicle suspensions were carried out with DADS program including component flexibility, and the durability analysis of vehicle components was executed with MSC/Fatigue program using the load history obtained from vehicle dynamic simulation. Driving test of a vehicle was also carried out to obtain precise input data for the durability analysis, and the results of virtual durability analysis were compared to those of experiments.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.6
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• pp.1321-1328
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• 2015

The automobiles in Korea have approximately 60 years of history and this is relatively short compared to advanced countries. However, considering the traffic accident rate or severity related to automobiles, various efforts are required to reduce traffic accidents. Various problems caused by traffic accidents are not only related to individual damages but also have become social problems. In order to resolve this, it is important to analyze the cause of traffic accidents. This study aims to suggest methods to reduce traffic accidents by analyzing driving behavior, which is one of the reasons for a number of traffic accidents that were collected through traffic accident videos reported using DVRs (Driving Video Recorder) and were aired to the public via a SBS TV program for the past two years and four months. In particular, unlike other existing studies that aim at analyzing the causes of traffic accidents simply using data, this study constructed a database by analyzing every single DVR that stores the situation before and after the accident using relatively high-resolution video information to provide practical plans to reduce traffic accidents through statistical analysis.

• Journal of the Korean Geotechnical Society
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• v.20 no.5
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• pp.145-159
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• 2004

The conventional method for assessment of liquefaction potential proposed by Seed and Idriss has been widely used in most countries because of simplicity of tests. Even though various data such as stress, strain, stress path, and excess pore water pressure can be obtained from the dynamic test, especially, two simple experimental data such as the maximum deviatoric stress and the number of cycles at liquefaction have been used in the conventional assessment. In this study, a new detailed assessment for liquefaction potential to reflect both characteristics of real earthquake motion and dynamic soil resistance is proposed and verified. In the assessment, the safety factor of the liquefaction potential at a given depth of a site can be obtained by the ratio of a resistible cumulative plastic shear strain determined through the performance of the conventional cyclic test and a driving cumulative plastic shear strain calculated from the shear strain time history through the ground response analysis. The last point to cumulate the driving plastic shear strain to initiate soil liquefaction is important for this assessment. From the result of cyclic triaxial test using real earthquake motions, it was concluded that liquefaction under the impact-type earthquake loads would initiate as soon as a peak loading signal was reached. The driving cumulative plastic shear strain, therefore, can be determined by adding all plastic shear strains obtained from the ground response analysis up to the peak point. Through the verification of the proposed assessment, it can be concluded that the proposed assessment for liquefaction potential can be a progressive method to reflect both characteristics of the unique soil resistance and earthquake parameters such as peak earthquake signal, significant duration time, earthquake loading type, and magnitude.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.200-215
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• 2023

With the rapid advance of autonomous driving technology, the related vehicle market is experiencing explosive growth, and it is anticipated that the era of fully autonomous vehicles will arrive in the near future. However, along with the development of autonomous driving technology, questions regarding its safety and reliability continue to be raised. Concerns among technology adopters are increasing due to media reports of accidents involving autonomous vehicles. To promote the improvement of the safety of autonomous vehicles, it is essential to analyze previous accident cases and identify their causes. Therefore, in this study, we aimed to analyze the factors influencing the severity of autonomous vehicle accidents using previous accident cases and related data. The data used for this research primarily comprised autonomous vehicle accident reports collected and distributed by the California Department of Motor Vehicles (CA DMV). Spatial information on accident locations and additional traffic data were also collected and utilized. Given that the primary data used in this study were accident reports, a Poisson regression analysis was conducted to model the expected number of accidents. The research results indicated that the severity of autonomous vehicle accidents increases in areas with low lighting, the presence of bicycle or bus-exclusive lanes, and a history of pedestrian and bicycle accidents. These findings are expected to serve as foundational data for the development of algorithms to enhance the safety of autonomous vehicles and promote the installation of related transportation infrastructure.

• Journal of Information Technology Services
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• v.12 no.2
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• pp.171-184
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• 2013

Frequently faced with dangerous situations, for evidentiary purpose in case of civil and criminal liability challenges, car drivers in Korea have been armed with so-called 'black boxes'; however, which are just video recorders in vehicles rather than real 'black boxes' that are equipped in the airplanes. In the United States, they are called EDRs(Event Data Recorders), more technically, which means that they record data of events happened while driving, such as velocity changes, airbags deployment, seatbelt wearing etc. just like in the airplanes. EDR technology is quickly becoming more advanced, more widely available, and less expensive; however, new concerns are emerging : the privacy of drivers. In U. S., vehicle manufacturers and insurance companies and the governmental agencies including the courts and legislatures are the main parties in terms of the EDR concerns. In order to determine the best way to regulate EDR, it is necessary to balance all the merits, such as safety, privacy, truth, justice and efficiency, to support a legal framework regulating the EDR concerns. This article, in light of the regulation of EDR and experience therof in the United States, examines EDR technology itself, particularly with respect to the automobile industry, describing its history, its current state, and trends that may change it in the future; and explains how the National Highway Transportation Safety Agency (NHTSA), legislatures, courts have approached EDR data. At the early stage of regulation on EDRs in Korea, examining U. S. legal framework and usages would help for successful establishment of legislation and regulation.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.11
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• pp.4477-4487
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• 2015

In this review we summarize the results of studies employing high-throughput methods of profiling of HPV-associated cervical intraepithelial neoplasia (CIN) and squamous cell cervical cancers at key intracellular regulatory levels to demonstrate the unique identity of the landscape of molecular changes underlying this oncopathology, and to show how these changes are related to the 'natural history' of cervical cancer progression and the formation of clinically significant properties of tumors. A step-wise character of cervical cancer progression is a morphologically well-described fact and, as evidenced by genome-wide screenings, it is indeed the consistent change of the molecular profiles of HPV-infected epithelial cells through which they progressively acquire the phenotypic hallmarks of cancerous cells. In this sense, CIN/cervical cancer is a unique model for studying the driving forces and mechanisms of carcinogenesis. Recent research has allowed definition of the whole-genome spectrum of both random and regular molecular alterations, as well as changes either common to processes of carcinogenesis or specific for cervical cancer. Despite the existence of questions that are still to be investigated, these findings are of great value for the future development of approaches for the diagnostics and treatment of cervical neoplasms.

• Journal of the Korean housing association
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• v.22 no.1
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• pp.11-23
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• 2011

The purpose of this study is to explore cohort changes in first-time homeownership in Korea. The study collected qualitative data from individual interviews to explore the housing trajectories of different birth cohorts. As a result, Individual interviews facilitated an exploration of the decision making process of first-time homeowner with in a cohort context. The cohorts born in the 1950s seek a sense of security through homeownership, and have strong Korean sentiments of ownership. They tried various means to buy a house, and real estate market boom at that time played a role in the driving force. The cohorts born in the 1960s have less insecurity of tenure than the previous cohorts, but they still feel the need for homeownership. Since the currency crisis in 1997 caused the fluctuation of housing price, the 1960s cohort experienced a dramatic decline and rebound of assets while the previous cohorts had experienced a steady rise in housing prices. Finally, the attitude towards housing in the group of 1970s cohorts has changed from ownershiporiented to use-oriented.