• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.5
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• pp.333-342
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• 2012

We studied the characteristics of spatial distribution of global wave height and carried out the modelsensitivity test by changing the input field, model resolution and physical factor (effective wind factor) since the spatial and temporal resolution in wind wave forecasting is one of most important factors. Comparisons among the different cases, and also between model, buoy and satellite data have been made. As a results of the wind-wave model run using the high resolution wind field, the bias of significant wave height showed the positive tendency and the Root-Mean Square Error(RMSE) was a bit decreased based on the comparison with buoy data. When the model resolution was changed to higher, the bias and RMSE was increased, and as the effective wind factor was smaller than default value(= 1.4) the bias and RMSE showed also decreasing pattern.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.91-94
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• 2006

KORDI(Korea Ocean Research & Development Institute) built a research vessel JANG-MOK with 40 G/T for a survey and observation of oceanographic environmental characteristics at coastal region in September 2005. This paper introduced the implementation for hardware and software of an integrated information network that loaded in JANG-MOK, and depicted the function of an integrated information network, such as an installation of ga-bit based network, RS232C serial & UDP network interface of instruments, a data logging software of measured data, Hawkeye II software for supporting the efficient survey works, and a real-time navigation viewer. In addition, we presents the another implementation method for an integrated information network of oceanographic research vessels.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.2
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• pp.206-212
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• 2006

Many image and video compression algorithms work by splitting the input image into blocks and producing variable-length coded bits for each block data. If variable-length coded data are transmitted consecutively, then the resulting coder is highly sensitive to channel errors. Therefore, most image and video techniques for providing some protection to the stream against channel errors usually involve adding a controlled amount of redundancy back into the stream. Such redundancy might take the form of resynchronization markers, which enable the decoder to restart the decoding process from the known state, in the event of transmission errors. The Error Resilient Entropy Code (EREC) is a well known method which can regain synchronization without any redundant information to convert from variable-length code to fixed-length code. This paper proposes an enhancement to EREC, which greatly improves its transmission ability for the compressed image quality without any redundant bits in the event of errors. The simulation result shows that the both objective and subjective quality of transmitted image is enhanced compared with the existing EREC at the same BER(Bit Error Rate).

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.12
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• pp.391-398
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• 2015

This paper devises a performance improvement and evaluation process of circuit minimization algorithms for mentorship education of distinguished informatics gifted secondary students. In the process, students learn that there are several alternative equivalent circuits for a target function and recognize the necessity for formalized circuit minimization methods. Firstly, they come at the concept of circuit minimization principle from Karnaugh Map which is a manual methodology. Secondly, they explore Quine-McCluskey algorithm which is a computational methodology. Quine-McCluskey algorithm's time complexity is high because it uses set operations. To improve the performance of Quine-McCluskey algorithm, we encourage them to adopt a bit-wise data structure instead of integer array for sets. They will eventually see that the performance achievement is about 36%. The ultimate goal of the process is to enlarge gifted students' interest and integrated knowledge about computer science encompassing electronic switches, logic gates, logic circuits, programming languages, data structures and algorithms.

• Women's Health Nursing
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• v.25 no.4
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• pp.434-445
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• 2019

Purpose: This study was conducted to examine the relationship between a mother's diagnosis of cervical cancer and attitudes toward cervical cancer prevention in their daughters. Their intention to recommend human papillomavirus (HPV) vaccination for their daughters, their confidence in 8 methods for cervical cancer prevention with their daughters, and their negative emotions about the assumption of their daughter's HPV infection. Methods: This study was a secondary analysis of data from the study of maternal health beliefs about preventing cervical cancer. The study sample were women who reported whether ever diagnosed with cervical cancer, who had pubertal daughters (n=1,578). Data were analyzed by cross-tabulation analysis, Spearman's rank correlation analysis, and logistic regression. Results: Mothers diagnosed with cervical cancer were more confident in using methods to prevent cervical cancer in their daughters (Z=-4.42, p<.001) and were more likely to feel negative emotions about the assumption of their daughters' HPV infection (Z=-2.44, p=.015) than mothers who were not diagnosed. Significant factors influencing their intention to recommend the HPV vaccination to their daughters were the mother's confidence in preventing cervical cancer in their daughters (odds ratio [OR], 1.003; 95% confidence interval [CI], 1.002-1.004) and their negative emotions about the assumption of their daughters' HPV infection (OR,1.016; 95% CI, 1.004-1.028). Conclusion: For the early prevention of cervical cancer in pubertal daughters, the education of their mothers should include interventions to increase confidence in preventing cervical cancer in their daughters and sensitivity of HPV infection toward daughters.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.707-715
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• 2008

This paper proposes an algorithm for efficient compression gray-level images by entropy encoder. The issue of the proposed method is to replace original data of gray-level images with particular ranked data. For this, first, before encoding a stream of gray-level values in an image, the proposed method counts co-occurrence frequencies for neighboring pixel values. Then, it replaces each pay value with particularly ranked numbers based on the investigated co-occurrence frequencies. Finally, the ranked numbers are transmitted to an entropy encoder. The proposed method improves the performance of existing entropy coding by transforming original gray-level values into rank based images using statistical co-occurrence frequencies of gray-level images. The simulation results, using gray-level images with 8-bits, show that the proposed method can reduce bit rate by up to 37.85% compared to existing conventional entropy coders.

• Smart Structures and Systems
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• v.2 no.2
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• pp.115-126
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• 2006

The Terra-Scope system is an affordable 4-D down-hole seismic monitoring system based on independent, microprocessor-controlled sensor Pods. The Pods are nominally 50 mm in diameter, and about 120 mm long. They are expected to cost approximately $6000 each. An internal 16-bit, extremely low power MCU controls all aspects of instrumentation, eight programmable gain amplifiers, and local signal storage. Each Pod measures 3-D acceleration, tilt, azimuth, temperature, and other parametric variables such as pore water pressure and pH. Each Pod communicates over a standard digital bus (RS-485) through a completely web-based GUI interface, and has a power consumption of less than 400 mW. Three-dimensional acceleration is measured by pure digital force-balance MEMS-based accelerometers. These accelerometers have a dynamic range of more than 115 dB and a frequency response from DC to 1000 Hz with a noise floor of less than $30ng_{rms}/{\surd}Hz$. Accelerations above 0.2 g are measured by a second set of MEMS-based accelerometers, giving a full 160 dB dynamic range. This paper describes the system design and the cooperative shared-time scheduler implemented for this project. Restraints accounted for include multiple data streams, integration of multiple free agents, interaction with the asynchronous world, and hardened time stamping of accelerometer data. The prototype of the device is currently undergoing evaluation. The first array will be installed in the spring of 2006.

• KSCI Review
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• v.2 no.1
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• pp.55-67
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• 1995

Recently, it is possible to high speed transmission of the non-voiced data, including voice, data, moving image instead of voice only in the past by changing the communication method to digital form from analog owing to the development of semiconductor and computer technology which for information transmission of the remote point. By doing so, we can get the improvement of the noise effect and low cost but the loss of transmission bandwidth. It is necessary to take some method in oreder to reducing the fading which is propotional to transmission bandwidth during the transmission of radio communication channel, especially. When we design the digital communication system, we must considered to the fading effect in order to determination of the transmitting power, modulation /demodulation method, transmission speed, bit error rate. This paper mainly concerns to the method to the channel simulator which descrives the fading effect during the transmission by computer model and digital filter modeling of the radio fading channel by unsing the transmitting and received signal. By taking the inverse of the characteristic of the modeled filter, it is possible to improvement of the communication system by reducing the distortion and inter-symbol interference which occurs in the channel.

• Journal of IKEEE
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• v.23 no.3
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• pp.954-961
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• 2019

This paper suggests an advanced 8T SRAM which can operate properly in subthreshold voltage regime. The memory cell consists of symmetric 8 transistors, in which the latch storing data is controlled by a column-wise assistline. During the read, the data storage nodes are temporarily decoupled from the read path, thus eliminating the read disturbance. Additionally, the cell keeps the noise-vulnerable 'low' node close to the ground, thereby improving the dummy-read stability. In the write, the boosted wordline facilitates to change the contents of the memory bit. At 0.4 V supply, the advanced 8T cell achieves 65% higher dummy-read stability and 3.7 times better write-ability compared to the commercialized 8T cell. The proposed cell and circuit techniques have been verified in a 16-kbit SRAM array designed with an industrial 180-nm low-power CMOS process.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.7 no.2
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• pp.55-72
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• 1997

This paper presents a digital signature scheme for facsimile document which directly embeds a signature onto the document. We use multiple reference lines which have been scanned just before and modify each distance of changing pels both on the reference line specified by key and on the coding line with a single bit of the signature data. The time to take in signature is reduced by spreading of signature. Non-repudiation in origin, the 3rd condition of digital signature is realized by proposed digital signature scheme. The transmitter embeds the signature secretly and transfers it, and the receiver makes a check of any forgery on the signature and the document. This scheme is compatible with the ITU-T.4(CCITT G3 or G4 facsimile standards). The total amount of data transmitted and the image quality are about the same to that of the original document, and thus a third party notices that no signature is embedded on the document.