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Study on the Physical Properties of Alkoxysilane-based Stone Consolidants with Different Hydrolysis (알콕시 실란계 석조문화재 강화제의 가수 분해도에 따른 특성 연구)

  • Park, Soung-Jin;Won, Jong-Ok;Kim, Jeong-Jin;Do, Jin-Young;Kim, Sa-Dug
    • Journal of Conservation Science
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    • v.27 no.2
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    • pp.201-209
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    • 2011
  • While consolidants based on tetraethoxysilane (TEOS) have been widely used for the consolidation of decaying stone heritages, TEOS-based consolidants suffer from practical drawbacks, such as crack formation of the gel during the drying phase due to the developed capillary force. We have prepared new TEOS-based consolidants containing flexible (3-glycidoxypropyl) trimethoxysilane (GPTMS) in order to reduce capillary force development during gel drying. In this study, we have prepared TEOS/GPTMS-based consolidants containing ETEOS in order to improve the surface hydrophobisity. The physical properties of the TEOS/GPTMS/ETEOS solution with different hydrolysis were compared with those of the commercial products Wacker OH$^{(R)}$. The contact angle of the surface increased with the addition of the ETEOS, which is higher than that of Wacker OH$^{(R)}$. The sol-gel mechanism was manipulated by the degree of hydrolysis as well as the amount of ETEOS. The properties and the applicability of the developed consolidants for the decayed Korean granites are also investigated.

Contactless Fingerprint Recognition Based on LDP (LDP 기반 비접촉식 지문 인식)

  • Kang, Byung-Jun;Park, Kang-Ryoung;Yoo, Jang-Hee;Moon, Ki-Young;Kim, Jeong-Nyeo;Shin, Jae-Ho
    • Journal of Korea Multimedia Society
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    • v.13 no.9
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    • pp.1337-1347
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    • 2010
  • Fingerprint recognition is a biometric technology to identify individual by using fingerprint features such ridges and valleys. Most fingerprint systems perform the recognition based on minutiae points after acquiring a fingerprint image from contact type sensor. They have an advantage of acquiring a clear image of uniform size by touching finger on the sensor. However, they have the problems of the image quality can be reduced in case of severely dry or wet finger due to the variations of touching pressure and latent fingerprint on the sensor. To solve these problems, the contactless capturing devices for a fingerprint image was introduced in previous works. However, the accuracy of detecting minutiae points and recognition performance are reduced due to the degradation of image quality by the illumination variation. So, this paper proposes a new LDP-based fingerprint recognition method. It can effectively extract fingerprint patterns of iterative ridges and valleys. After producing histograms of the binary codes which are extracted by the LDP method, chi square distance between the enrolled and input feature histograms is calculated. The calculated chi square distance is used as the score of fingerprint recognition. As the experimental results, the EER of the proposed approach is reduced by 0.521% in comparison with that of the previous LBP-based fingerprint recognition approach.

Implementation a of data repeating system using solar charging and develop algorithm for data repeating in the pasture (산지초지에서 한우 활동량 정보 수집을 위한 데이터 중계 알고리즘 및 시스템 구현)

  • Kim, Suc-Jun;Kim, Jong-Won;Kim, Chun-Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.11
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    • pp.285-293
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    • 2016
  • In the paper, we propose a data transmission repeating system that allows data transmission for the effective supervision of cows grazing in the pasture. It is normal practice to divide the pasture into different areas for the purpose of distributing the grazing. However, this makes it difficult to supply electrical power and transmit data, because some of the pastures are far away from the office used for collecting data. To solve this problem, we developed a repeating system that can allow data transmission in the pasture using a solar charging system that consists of a 60W solar panel, 12V/100A battery and 6A solar controller for the power supply and a data transmission algorithm which extends the range of data transmission when using the proposed repeating system. We verified the performance of the repeating system by checking whether the data transmission is successful or not when transmitting from various test points when there is an obstacle between the receiver and repeating system. We also verified the solar charging system by measuring the battery voltage when the system is operated continuously for 31 days and whether the system can supply sufficient power when the weather is cloudy or rainy for a few days. Finally, we verified the performance of the repeating system and data transmission algorithm by conducting experiments in a pasture.

The Effect of Information Security Breach and Security Investment Announcement on the Market Value of Korean Firms (정보보안 사고와 사고방지 관련 투자가 기업가치에 미치는 영향)

  • Kwon, Young-Ok;Kim, Byung-Do
    • Information Systems Review
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    • v.9 no.1
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    • pp.105-120
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    • 2007
  • With the fast development of the Internet and the increasing dependence on information infrastructures, companies are faced with various information security threats such as information leakages, modifications, and information breaches. South Korea is one of the leading countries in the Internet usage, but is ranked relatively low when it comes to information security. In fact, many Korean firms have suffered financial losses and damaged corporate images from the information security breaches. However, because of the difficulties in quantifying the costs of the information security breaches, Korean companies tend to delay their investment decisions on information security. The purpose of this study is to measure the cost of information security breach and the economic value of security investment using the event study methodology. Our results show that the announcement of an information security breach negatively influenced the market value of the corresponding company. The effect was statistically significant at the significance level of p=0.05. The breached companies lose, on average, 0.86% of their market values on the day of the announcement - an average loss in market capitalization of $55 million. On the other hand, the investment on information security had no effect on the stock price or the market value of the firm.

Characteristics of reproductive effect and phenology of Polygonatum stenophyllum grown in riverside in Paju-si (파주시 하천변에 서식하는 층층둥굴레의 계절학과 번식생태학적 특성)

  • Kim, Eui-Joo;Hong, Yong-Sik;Park, Jae-Hoon;Lee, Soo-In;Lee, Eung-Pill;Lee, Seung-Yeon;You, Young-Han
    • Journal of Wetlands Research
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    • v.22 no.2
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    • pp.73-80
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    • 2020
  • Polygonatum stenophyllum Maxim. is a native perennial herb to Korea belonging to family Liliaceae. Although it was removed from the endangered species list, since it inhabits the riverside, it has been threatened with damage to its populations due to frequent disturbances. In order to reveal the basic ecological characteristics of P. stenophyllum, This study was identified the life cycle of the aboveground part and was measured the number of flowers and fruits, which are reproductive organs of P. stenophyllum in riverside in Paju - si during the two years. As a result, aboveground part of P. stenophyllum appeared and grew rapidly until the end of May to about 1m. In early May, two buds per one peduncle were formed up to six pairs per floor. The flowers bloomed in turn from the base of the stem and to the top floor and the blooming occurred when the number of leaves was at least three. Fruits were formed in mid-June and matured by the end of September. The numbers of flowers and fruits were revealed that flowers bloomed in turn from the bottom of the stem to the top floor, the most intensively bloomed in the center part of the stem, and did not bloom from the floor closest to the ground and above the highest 5th node. This basic ecological characteristics of the P. stenophllyum grown in riverside identified in this study will be useful as basic data for their conservation.

A Study of a Fast Booting Technique for a New memory+DRAM Hybrid Memory System (뉴메모리+DRAM 하이브리드 메모리 시스템에서의 고속부팅 기법 연구)

  • Song, Hyeon Ho;Moon, Young Je;Park, Jae Hyeong;Noh, Sam H.
    • Journal of KIISE
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    • v.42 no.4
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    • pp.434-441
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    • 2015
  • Next generation memory technologies, which we denote as 'new memory', have both non-volatile and byte addressable properties. These characteristics are expected to bring changes to the conventional computer system structure. In this paper, we propose a fast boot technique for hybrid main memory architectures that have both new memory and DRAM. The key technique used for fast booting is write-tracking. Write-tracking is used to detect and manage modified data detection and involves setting the kernel region to read-only. This setting is used to trigger intentional faults upon modification requests. As the fault handler can detect the faulting address, write-tracking makes use of the address to manage the modified data. In particular, in our case, we make use of the MMU (Memory Management Unit) translation table. When a write occurs to the boot completed state, write-tracking preserves the original state of the modified address of the kernel region to a particular location, and execution continues. Upon booting, the fast booting process restores the preserved data to the original kernel region allowing rapid system boot-up. We develop the fast booting technique in an actual embedded board equipped with new memory. The boot time is reduced to less than half a second compared to around 15 seconds that is required for the original system.

Deterioration and Microclimate in the Shelter for the Gaetaesajiseokbulibsang (Standing Triad Buddha Statues in Gaetaesaji Temple Site), Nonsan, Korea (논산 개태사지석불입상의 손상도와 보호각 내부의 미기후 환경)

  • Kim, Ji-Young;Park, Sun-Mi;Lee, Chan-Hee
    • Journal of Conservation Science
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    • v.25 no.2
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    • pp.179-196
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    • 2009
  • The Gaetaesajiseokbulibsang (Treasure No. 219) consists of light gray and coarse to medium-grained granodiorite with feldspar phenocrysts in part. Magnetic susceptibility of the rock material was measured as 12.06(${\times}10^{-3}$ SI unit), being different from the granite($0.19{\times}10^{-3}$ SI unit) in the Mt. Cheonho. This indicates the raw material has been supplied from the outside. As a result of deterioration assessment, exfoliation of the Right Buddha, cement and dust of the Main Buddha were estimated as 35.2%, 21.1% and 25.0%. The ultrasonic velocity was measured as 2850.2m/s(Main Buddha), 2648.4m/s(Left Buddha) and 2644.5m/s(Right Buddha). The compressive strength calculated from the velocity showed low in the Right Buddha among three and the all pedestal parts which corresponds to the result of deterioration assessment. The indoor mean temperature and relative humidity of the shelter were $13.7^{\circ}C$ and 79.0%. It is evaluated that the indoor microclimate was stable and the shelter functioned to reduce climatic fluctuation of the outdoor. However, water condensation was occurred on the surface of the pedestal part during spring and summer, and freezing in winter season might also be done. These factors were probable to be a main cause of the surface exfoliation of the Triad Buddha Statues. Therefore, dehumidification and heating system in the shelter should be applied to prevent further deterioration.

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Tertiarization and Changes in the Demand for Job-based Skills - Focusing on Cognitive Skills and Interactive Skills - (서비스화가 일자리 숙련구조에 미친 영향 - 인지적 숙련 및 상호적 숙련을 중심으로 -)

  • Hwang, Soo Kyeong
    • Journal of Labour Economics
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    • v.30 no.3
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    • pp.1-41
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    • 2007
  • Since Korea experienced a 'jobless growth' in 2003, creating jobs in the service sector has been considered as a top priority employment agenda. However, despite high employment outcomes in services, labor productivity remains stagnant in the service sector in recent years. A great deal of concern has been raised regarding newly created service jobs. Critics say low productivity in the service sector will harm the engine of economic growth in our country. This paper investigates the side of the demand for quality of labor, namely, the demand for skills as one of the main source of low productivity in the service sector. To analyze the changes of skills demand, this paper suggests the concept of job-based skills instead of worker-based skills and presents the way of constructing measures of job-based skills. By means of common factor analysis using job information in the Korean Dictionary of Occupational Titles, I extract 4 direct measures of job-based skills, such as cognitive skills, physical skills, fine skills, interactive skills. These skill measures are used to explore and to test how the skill structure changed in the service sector during 2002-2006. Empirical Results show that whereas the goods sector makes progress toward upskilling being represented by increased cognitive elements and softenization of tasks, the service sector, although high-educated workers increased, exhibits trends of deskilling in the sense of job-based skills during 2002-2006 in Korea. The trend of deskilling however does not seem a general aspect in the overall service sector. Rather, it seems a compound process that high-skilled jobs are created, but, on the other hand low-skilled jobs requiring physical labor are produced at the same time.

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Statistical review and explanation for Lanchester model (란체스터 모형에 대한 통계적 고찰과 해석)

  • Yoo, Byung Joo
    • The Korean Journal of Applied Statistics
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    • v.33 no.3
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    • pp.335-345
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    • 2020
  • This paper deals with the problem of estimating the log-transformed linear regression model to fit actual battle data from the Ardennes Campaign of World War II into the Lanchester model. The problem of determining a global solution for parameters and multicollinearity problems are identified and modified by examining the results of previous studies on data. The least squares method requires attention because a local solution can be found rather than a global solution if considering a specific constraint or a limited candidate group. The method of exploring this multicollinearity problem can be confirmed by a statistic known as a variance inflation factor. Therefore, the Lanchester model is simplified to avoid these problems, and the combat power attrition rate model was proposed which is statistically significant and easy to explain. When fitting the model, the dependence problem between the data has occurred due to autocorrelation. Matters that might be underestimated or overestimated were resolved by the Cochrane-Orcutt method as well as guaranteeing independence and normality.

Hydraulic Characteristics Investigation due to the Change of GapWidth between Artificial Reefs (인공리프 개구폭 변화에 따른 흐름특성 고찰)

  • Kim, Kyu-Han;Shim, Kyu-Tae
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.28 no.6
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    • pp.408-415
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    • 2016
  • Small fishing ports and coastal structures installed in a relatively low sea water depth disturb the wave induced current and cause the collapse of equilibrium state of sediment transport. These structures creates diffracted waves and matter the concentration of waves to cause the beach erosion. In order to mitigate these eroding problems on the beach, many counter measurements were proposed such as detached breakwater, groin or headland; however, these methods interrupt the aesthetic view of sandy beach due to the exposed structures above the sea level and have difficulty of applying to those beaches with the good scenery. Furthermore, some of these methods create secondary environmental problems after the installations. To eliminate these problems, one of the countermeasures, artificial reefs have been selected and used worldwide to minimize the disturbance of the scenery and secondary effects on the environment. Meanwhile, it is important to set the design elements for installing the artificial reefs such as that of length, opening width, clearing distances from the shoreline and more. Nevertheless, there are no construction manuals or standards for designing the artificial reefs with these important design elements yet. In this study, different conditions of artificial reefs were used with various cases throughout hydraulic model test to precisely analyze the changes of waves and currents to propose the standards of design elements to install the artificial reefs.