• The KIPS Transactions:PartC
• /
• v.13C no.4 s.107
• /
• pp.397-404
• /
• 2006

Successful software attacks require both injecting malicious code into a program's address space and altering the program's flow control to the injected code. Code section can not be changed at program's runtime, so malicious code must be injected into data section. Detoured flow control into data section is a signal of software attack. We propose a new software attack detection method which verify the target address of CALL, JMP, RET instructions, which alter program's flow control, and detect a software attack when the address is not in code section. Proposed method can detect all change of flow control related data, not only program's return address but also function pointer, buffer of longjmp() function and old base pointer, so it can detect the more attacks.

• Broadcasting and Media Magazine
• /
• v.11 no.1
• /
• pp.68-77
• /
• 2006

The Cognitive Radio (CR) technology is a promising solution for exploiting the limited spectrum resources and providing flexibility of spectrum usage. Future interactive broadcasting service can be realized by utilizing CR concept, since the up-link return channel can be found by the spectrum sensing method, which is core functional block of the CR system. In this paper, the spectrum sensing technologies of CR system is presented. First the system architecture of the CR with spectrum sensing block is presented. The suggested spectrum sensing technique consists of the coarse and the fine spectrum sensing. The coarse spectrum sensing technique adopted the wavelet transform to provide the multi-resolution sensing feature - Multi-Resolution Spectrum Sensing (MRSS). The fine spectrum sensing technique uses the beneficial properties of the autocorrelation function Analog Auto-Correlation (AAC). The simulation results for the proposed sensing technologies are presented for various incumbent signals.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.21 no.3
• /
• pp.224-229
• /
• 2009

Partial safety factors(PSFs) for Level I reliability based design of caisson type quay walls were calculated. First order reliability method(FORM) based PSFs are the functions of sensitivities of limit state function with respect to design random variables, target reliability index, characteristic values and first moment of random variables. Modified PSFs for water level and resilient water level are newly defined to keep consistency with the current design code. In the numerical example, PSFs were calculated by using a target reliability index. Seismic coefficient is defined to show extreme distribution. It was found that PSFs for seismic coefficient becomes smaller as the return period for design seismic coefficient grows longer.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
• /
• v.6 no.1
• /
• pp.17-27
• /
• 1995

In this paper, Finite Difference Time Domain (FDTD) method is used to analyze characteristics of the electromagnetically coupled broadband microstrip antenna, and to optimize the antenna parameters. By using short tuning stub in feedline, electromagnetically coupled microstrip antenna shows broadband (approximatcly equal 13%) characteristics, and the characteristics are varied as a function of length, width, and position of the tuning stub. Operating frequency, return loss, VSWR and input impedance are calculated by Fourier transforming the time domain results. Measurement data from fabricated electromagnetically coupled microstrip antenna are compared with FDTD results and are shown to be in good agreement. After optimization of the parameters, maximum bandwidth of about 15% is achieved.

• Journal of Electrical Engineering and Technology
• /
• v.7 no.6
• /
• pp.859-868
• /
• 2012

A new fault location algorithm based on stationary wavelet transform and its verification experiment results are described for HVDC submarine cables in this paper. For wavelet based fault location algorithm, firstly, 4th level approximation coefficients decomposed by wavelet transform function are superimposed by correlation, then the distance to the fault point is calculated by time delay between the first incident signal and the second reflected signal. For the verification of this algorithm, the real experiments based on various fault conditions and return types of fault current are performed at HVDC submarine cable test yard located in KEPCO(Korea Electric Power Corporation) Power Testing Center of South Korea. It proves that the fault location method proposed in this paper is very simple but very quick and accurate for HVDC submarine cable fault location.

• Physical Therapy Rehabilitation Science
• /
• v.11 no.4
• /
• pp.579-584
• /
• 2022

Objective: To identify the effect of unstable surface kettlebell exercises on muscle activity and balance in middle and high school baseball players. Design: Randomized controlled trial. Methods: The participants were 29 middle and high school baseball players (Unstable surface kettlebell exercises group, USKE: 15; Stable surface kettlebell exercise group, SSKE: 14). The players in the USKE group performed kettlebell exercises for 60 mins on a stable surface thrice a week for 6 weeks, and the return rack was solidified on a stable surface in the same way as the experimental group. Before and after the experiment, the participant's muscle activity of the tibialis anterior and soleus was measured. In addition, the participant's balance was evaluated by measuring the distance moved from the foot's center of pressure (COP). The paired t-test was used to compare groups before and after the experiment. The independent t-test was conducted to assess differences in the degree of change between the two groups before and after the experiment. Results: Compared to the SSKE group, the USKE group showed significant differences in the muscle activity of the tibialis anterior and soleus and the balance with the eyes open and closed. Conclusions: The players in the USKE group showed a significant difference in muscle activity and balance than in those in the SSKE group. Thus, effectively including an unstable surface in the kettlebell exercise program will help improve physical function in athletes and people with musculoskeletal disorders.

• Korea Journal of Hospital Management
• /
• v.22 no.2
• /
• pp.1-16
• /
• 2017

1) Purpose: The goal of this study is to examine the association between independent external financial audits and uncompensated care. Not-for-profit hospitals are required to provide uncompensated care in return for tax exemption. These tax exemption benefits are applied to all activities that contribute to the enhancement of uncompensated care. However, some researchers argue not-for-profit hospitals do not provide uncompensated care as expected by their tax exemption. Thus, this paper examines whether independent external financial audits can help the not-for-profit hospitals to function as designed and ultimately for meeting the objectives of the not-for-profit organization, which are the clearest examples of charitable activities performed by not-for-profit hospitals. 2) Methodology: Panel data analysis was utilized with fixed effect using California hospital financial data from 2002 to 2011. 3) Findings: We found that hospitals receiving independent external financial audits provide more uncompensated care than their counterparts which do not receive audits. 4) Practical Implications: Not-for-profit hospitals provide uncompensated care to people in welfare blind spots. Therefore, they fulfill what governments cannot afford, and play a social role as a ʻnonprofitʼ organization with independent external financial audits.

• Safety and Health at Work
• /
• v.1 no.1
• /
• pp.1-10
• /
• 2010

The Finnish risk assessment practice is based on the Occupational Safety and Health (OSH) Act aiming to improve working conditions in order maintain the employees' work ability, and to prevent occupational accidents and diseases. In practice there are hundreds of risk assessment methods in use. A simple method is used in small and medium sized enterprises and more complex risk evaluation methods in larger work places. Does the risk management function in the work places in Finland? According to our experience something more is needed. That is, understanding of common and company related benefits of risk management. The wider conclusion is that commitment for risk assessment in Finland is high enough. However, in those enterprises where OSH management was at an acceptable level or above it, there were also more varied and more successfully accomplished actions to remove or reduce the risks than in enterprises, where OSH management was in lower level. In risk assessment it is important to process active technical prevention and exact communication, increase work place attraction and increase job satisfaction and motivation. Investments in OSH are also good business. Low absenteeism due to illness or accidents increases directly the production results by improved quality and quantity of the product. In general Finnish studies have consistently shown that the return of an invested euro is three to seven-old. In national level, according to our calculations the savings could be even 20% of our gross national product.

• International conference on construction engineering and project management
• /
• 2005.10a
• /
• pp.774-779
• /
• 2005

Client requirements is a concept with increasing interest in relation to several outcomes of companies, and in particular, in the event of apartment project that takes large share in the domestic construction industry, diverse angle of survey is performed to discover the client requirements and reflect them to the project to improve the quality. For this purpose, it is required to learn the client requirements and apply it in the apartment project, and the QFD (Quality Function Deployment) linked ROQ (Return On Quality) is a technique used in the manufacturing that surveys the client requirements to improve the customer satisfaction, and apply it to the quality improvement program to improve the profitability in this process. In this study, through the application of the ROQ process, the plan to improve the apartment quality management is presented. For this purpose, the consumer interview survey, FGI (focus group interview) survey and the client requirements are analyzed, and thereafter, through the interview with the specialist, the quality improvement program that enables the application to the product development of new apartment product is established. Through this process, the new apartment quality management improvement plan is presented.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.5
• /
• pp.528-536
• /
• 2010

A monopulse feeder gives the most important impact upon the radiation pattern characteristics of a multi-function radar or a tracking radar which uses the space feed. It is described that the triple-mode type monopulse feeder which possesses the optimum aperture illumination for three monopulse channels is designed and measured in this paper. The measured results show that the designed feeder has not only the characteristics of the optimum aperture illimination in each channel and also very low return loss over the 10 % of fractional bandwidth at X-band. This means that the feeder provides the antenna system with low sidelobe level and high monopulse slope characteristics.