• Journal of KIISE:Computing Practices and Letters
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• v.10 no.2
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• pp.146-155
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• 2004

Currently most of commercial operating systems contain a high-level audit feature to increase their own security level. Linux does not fall behind the other commercial operating systems in performance and stability, but Linux does not have a good audit feature. Linux is required to support a higher security feature than C2 level of the TCSEC in order to be used as a server operating system, which requires the kernel-level audit feature that provides the system call auditing feature and audit event. In this paper, we present LxBSM, which is a kernel module to provide the kernel-level audit features. The audit record format of LxBSM is compatible with that of Sunshield BSM. The LxBSM is implemented as a loadable kernel module, so it has the enhanced usability. It provides the rich audit records including the user-level audit events such as login/logout. It supports both the pipe and file interface for increasing the connectivity between LxBSM and intrusion detection systems (IDS). The performance of LxBSM is compared and evaluated with that of Linux kernel without the audit features. The response time was increased when the system calls were called to create the audit data, such as fork, execve, open, and close. However any other performance degradation was not observed.

• Korean Journal of Food Science and Technology
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• v.49 no.5
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• pp.507-512
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• 2017

The physicochemical properties of maize starch sonicated at various amplitudes (100, 200, and 300 W) and times (10, 30, and 50 min) were examined. The amount of enzyme-susceptible starch increased marginally after sonication. Sonication increased the amount of oil absorbed in the starch although the degree of oil absorption decreased with an extension of the sonication time, implied that different types and extent of damages occurred. Scanning electron microscopy revealed that ultrasound sonication did not form pores on the surfaces, but caused damages such as depression and erosion. Pasting viscosity of starch decreased with an increase in the severity of sonication conditions because of the weakened polymer network. X-ray diffraction suggested that the crystalline domains in starch were not susceptible to sonication and were more resistance to degradation. Sonicated starch formed more pin-holes on the surfaces in the initial glucoamylase reaction; subsequently, as the reaction proceeded, porous starch with enlarged pores was formed and finally, disrupted granular fragments were observed.

• Journal of Internet Computing and Services
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• v.21 no.5
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• pp.1-7
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• 2020

Deep neural networks(DNN), which are used as approximation functions in reinforcement learning (RN), theoretically can be attributed to realistic results. In empirical benchmark works, time difference learning (TD) shows better results than Monte-Carlo learning (MC). However, among some previous works show that MC is better than TD when the reward is very rare or delayed. Also, another recent research shows when the information observed by the agent from the environment is partial on complex control works, it indicates that the MC prediction is superior to the TD-based methods. Most of these environments can be regarded as 5-step Q-learning or 20-step Q-learning, where the experiment continues without long roll-outs for alleviating reduce performance degradation. In other words, for networks with a noise, a representative network that is regardless of the controlled roll-outs, it is better to learn MC, which is robust to noisy rewards than TD, or almost identical to MC. These studies provide a break with that TD is better than MC. These recent research results show that the way combining MC and TD is better than the theoretical one. Therefore, in this study, based on the results shown in previous studies, we attempt to exploit a random balance with a mixture of TD and MC in RL without any complicated formulas by rewards used in those studies do. Compared to the DQN using the MC and TD random mixture and the well-known DQN using only the TD-based learning, we demonstrate that a well-performed TD learning are also granted special favor of the mixture of TD and MC through an experiments in OpenAI Gym.

• Smart Media Journal
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• v.9 no.1
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• pp.51-59
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• 2020

From PC communication to the development of the internet, a new term has been coined on the social media, and the social media culture has been formed due to the spread of smart phones, and the newly coined word is becoming a culture. With the advent of social networking sites and smart phones serving as a bridge, the number of data has increased in real time. The use of new words can have many advantages, including the use of short sentences to solve the problems of various letter-limited messengers and reduce data. However, new words do not have a dictionary meaning and there are limitations and degradation of algorithms such as data mining. Therefore, in this paper, the opinion of the document is confirmed by collecting data through web crawling and extracting new words contained within the text data and establishing an emotional classification. The progress of the experiment is divided into three categories. First, a word collected by collecting a new word on the social media is subjected to learned of affirmative and negative. Next, to derive and verify emotional values using standard documents, TF-IDF is used to score noun sensibilities to enter the emotional values of the data. As with the new words, the classified emotional values are applied to verify that the emotions are classified in standard language documents. Finally, a combination of the newly coined words and standard emotional values is used to perform a comparative analysis of the technology of the instrument.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.2
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• pp.107-116
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• 2006

Purpose:Maxillay sinus grafting is an effective treatment procedure to improve bone height in the posterior maxillar area for implant installation. Beta-tricalciumphosphate(${\beta}$-TCP) was introduced to be grafting substitute material, providing a reasonable bio-degradation time, no need for harvesting procedure. The purpose of this study is to evaluate bone healing & regeneration phase using histomorphometric and immunohistochemical analysis. Material & Methods:Sixteen rabbits were divided into 4 groups. Bi-lateral maxillary sinus membranes were elevated at each rabbits, ${\beta}$-TCP was augmented in left sinus, autogenous bone was augmented in right sinus. The rabbits were sacrificed at 2, 4, 8 and 12 weeks. We investigated the bone regeneration & growth factor expression. Results: 1. The mean new bone volume formation was 28.99${\pm}$6.55%, 49.54${\pm}$5.47%, 69.09${\pm}$8.90% in autogenous grafted area, and 22.86${\pm}$5.56%, 24.00${\pm}$4.09%, 34.11${\pm}$3.37% in ${\beta}$-TCP area at 4, 8, 12 weeks. Therefore, new bone formation in autogenous bone was significantly higher than ${\beta}$-TCP (p<0.05). 2. The BMP 2/4 expression in autogenous bone grafted area was higher at 4, 8 weeks. 3. There was no difference in expression pattern of BMP-7/PDGF/VEGF during grafted bone regeneration. Conclusion:The authors we conclude that the autogenous bone graft was faster than ${\beta}$-TCP in bone regeneration, and the BMP 2/4 were more important in graft bone regeneration.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.4
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• pp.864-870
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• 2017

This paper describes a Dual Buck Converter with mode control using variable Frequency to Voltage for portable devices requiring wide load current. The inherent problems of PLL compensation and efficiency degradation in light load current that the conventional hysteretic buck converter has faced have been resolved by using the proposed Dual buck converter which include improved PFM Mode not to require compensation. The proposed mode controller can also improve the difficulty of detecting the load change of the mode controller, which is the main circuit of the conventional dual mode buck converter, and the slow mode switching speed. the proposed mode controller has mode switching time of at least 1.5us. The proposed DC-DC buck converter was implemented by using $0.18{\mu}m$ CMOS process and die size was $1.38mm{\times}1.37mm$. The post simulation results with inductor and capacitor including parasitic elements showed that the proposed circuit received the input of 2.7~3.3V and generated output of 1.2V with the output ripple voltage had the PFM mode of 65mV and 16mV at the fixed switching frequency of 2MHz in hysteretic mode under load currents of 1~500mA. The maximum efficiency of the proposed dual-mode buck converter is 95% at 80mA and is more than 85% efficient under load currents of 1~500mA.

• Korean Journal of Remote Sensing
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• v.34 no.1
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• pp.1-15
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• 2018

Passive microwave sea surface temperatures (SST) were validated in the Northwest Pacific using a total of 102,294 collocated matchup data between Global Precipitation Measurement (GPM) / GPM Microwave Sensor(GMI) data and oceanic in-situ temperature measurements from March 2014 to December 2016. A root-mean-square (RMS) error and a bias error of the GMI SST measurements were evaluated to $0.93^{\circ}C$ and $0.05^{\circ}C$, respectively. The SST differences between GMI and in-situ measurements were caused by various factors such as wind speed, columnar atmospheric water vapor, land contamination near coastline or islands. The GMI SSTs were found to be higher than the in-situ temperature measurements at low wind speed (<6 m/s) during the daytime. As the wind speed increased at night, SST errors showed positive bias. In addition, other factors, coming from atmospheric water vapor, sensitivity degradation at a low temperature range, and land contamination, also contributed to the errors. One of remarkable characteristics of the errors was their latitudinal dependence with large errors at high latitudes above $30^{\circ}N$. Seasonal characteristics revealed that the errors were most frequently observed in winter with a significant positive deviation. This implies that SST errors tend to be large under conditions of high wind speeds and low SSTs. Understanding of microwave SST errors in this study is anticipated to compensate less temporal capability of Infrared SSTs and to contribute to increase a satellite observation rate with time, especially in SST composite process.

• Journal of the Korea Society of Computer and Information
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• v.16 no.6
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• pp.21-30
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• 2011

In the global IT market, a lot of issues for responding to various environmental regulations emerged. In case of the data centers, it is consuming huge amounts of energy to maintain. So there have been various technical attempts as Consolidation, Virtualization, Optimization to efficiently manage energy and data storage to fix the problems. In this paper, we propose a new RAID(Redundant Array of Independent Disks) mechanism which is differing the intensity of power consumption and works to provide data protection and disaster recovery(backup, mirroring etc.) to stratify multiple volumes. G-RAID minimize the power consumption and the lower of I/O performance by selecting the volume depending on the frequency of data access while classifying the power consumption between volumes in storage system. Also, it is possible that a filesystem and block map information of G-RAID is processed by basic unit which is group located in a row for the blocks to work efficiently and can minimize the performance degradation of block mapping load by the access frequency in each groups. As a result, we obtained to elevate a little bit of response time caused by block relocation work, but showed the decrease of power consumption by 38%.

• Animal cells and systems
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• v.4 no.2
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• pp.157-163
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• 2000

Yeast pheromone a-factor is a 13-amino acid peptide hormone that is synthesized as a part of a larger precursor, prepro-$\alpha$-factor, consisting of a signal peptide and a proregion of 64 amino acids. The carboxy-terminal half of the precursor contains four tandem copies of mature $\alpha$-factor. To investigate the molecular basis of intracellular sorting, proteolytic processing, and storage of the peptide hormone, yeast prepro-$\alpha$-factor precursors were heterologously expressed in rat pituitary $GH_3 cells. When cells harboring the precursor were metabolically labeled, a species of approximately 27 kD appeared inside the cells. Digestion with peptide: N-glycosidase F (PNG-F) shifted the molecular mass to a 19 kD, suggesting that the 27 kD protein was the glycosylated form as in yeast cells. The nascent polypeptide is efficiently targeted to the ER in the $GH_3 cells, where it undergoes cleavage of its signal peptide and core glycosylation to generate glycosylated pro-a-factor. To look at the post ER intracellular processing, the pulse-labelled cells were chased up to 2 hrs. The nascent propeptides disappeared from the cells at a half life of 30 min and only 10-25% of the newly synthesized, unprocessed precursors were stored intracellularly after the 2 h chase. However, about 20% of the pulse-labeled pro-$\alpha$-factor precursors were secreted into the medium in the pro-hormone form. With increasing chase time, the intracellular level of propeptide decreased, but the amount of secreted propeptide could not account for the disappearance of intracellular propeptide completely. This disappearance was insensitive to lysosomotropic agents, but was inhibited at $16^{circ}C or 20^{\circ}C$, suggesting that the turnover of the precursors was not occurring in the secretory pathway to trans Golgi network (TGN) or dependent on acidic compartments. From these results, it is concluded that a pan of these heterologous precursors may be processed at its paired dibasic sites by prohormone processing enzymes located in TGN/secretpry vesicles producing small peptides, and that the residual unprocessed precursors may be secreted into the medium rather than degraded intracellularly.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.1
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• pp.1-11
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• 2018

In this study, pro-oxidant($d2w^{(R)}$) and rPP/ZnO nanocomposite flexible films for food packaging were prepared, and their mechanical and antimicrobial properties were investigated. As a result, the carbonyl index and hydroxyl index increased with exposured time to heat and UV rays. Surface analysis showed that the addition of zinc oxide improved the dispersibility and compatibility of the polymer, so that the surface of the composite film was smooth and the zinc oxide particles were smaller than the compared film. And it kept the physical properties by heat and UV ray blocking effect, and it worked to reduce decomposition. In the antimicrobial activity test, the microbial reduction rate was 3 logs or more at the use concentration of zinc oxide. The tensile strength was increased and the elongation was decreased. Oxidative degradability of multi-layered film in UV exposured for 72 hours, the molecular weight of the film decreased by 75.6%, 1,294 g/mol Mn and 5,920 g/mol Mw. In the safety analysis of food packaging materials, we obtained that are in standard of polypropylene, a food contact material of domestic law.