• Title/Summary/Keyword: Cube root

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Does acellular dermal matrix expand in response to tissue expander inflation?

  • Yang, Chae Eun;Park, Kwang Hyun;Lee, Dong Won;Lew, Dae Hyun;Song, Seung Yong
    • Archives of Plastic Surgery
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    • v.46 no.1
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    • pp.34-38
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    • 2019
  • Background Acellular dermal matrices (ADMs) have recently become widely used in breast reconstruction, but the correlation between the final expander volume and the surface area of the ADM is not well understood. In this study, the expansion of the surface area of ADM and the expander volume was studied retrospectively in cases of acellular dermis-assisted tissue expander breast reconstruction. Methods Twenty cases of immediate breast reconstruction using an ADM-assisted tissue expander from January 2015 to December 2015 were evaluated. In all 20 cases, CGCryoDerm was used as the matrix, with a thickness of 1-3 mm. No slit incisions were made. Finally, the proportional increase in the area of the fully expanded ADM was compared to that of the tissue expander volume. Results The proportional increase in the ADM surface area was calculated to be from 1.1 to 2.46, with a mean value of 1.7. Additionally, under the assumption that the expander had a spherical shape, the increase in its radius (the cube root of its volume) was assessed. The range of the proportional increase in the expander radius was 1.1 to 2.24, with a mean value of 1.66. The proportional increase in the radius of the expanded ADM surface area ranged from 1.04 to 1.34, with a mean ratio of 1.28. Conclusions The results of this study confirmed that the ADM expanded when the tissue expander was inflated. However, the ADM expanded to a lesser extent than the tissue expander, indicating that the muscle and other tissues expanded more than the ADM when the tissue expander was inflated.

Faster MapToPoint over $F_{3^m}$ for Pairing-based Cryptosystems (페어링 암호 시스템을 위한 $F_{3^m}$에서의 효율적인 MapToPoint 방법)

  • Park, Young-Ho;Cho, Young-In;Chang, Nam-Su
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.21 no.6
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    • pp.3-12
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    • 2011
  • A hashing function that maps arbitrary messages directly onto curve points (MapToPoint) has non-negligible complexity in pairing-based cryptosystems. Unlike elliptic curve cryptosystems, pairing-based cryptosystems require the hashing function in ternary fields. Barreto et al. observed that it is more advantageous to hash the message to an ordinate instead of an abscissa. So, they significantly improved the hashing function by using a matrix with coefficients of the abscissa. In this paper, we improve the method of Barreto et al. by reducing the matrix. Our method requires only 44% memory of the previous result. Moreover we can hash a message onto a curve point 2~3 times faster than Barreto's Method.

Measurements and Data Processing for Blast Vibrations and Air-blasts (발파진동 및 발파소음의 측정 및 자료처리)

  • Choi, Byung-Hee;Ryu, Chang-Ha
    • Explosives and Blasting
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    • v.33 no.3
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    • pp.29-50
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    • 2015
  • Safe blast criteria based on the concept of scaled distances can be obtained from the statistical analysis on measured peak particle velocity data of blast vibrations. Two types of scaled distance widely used in Korea are the square root scaled distance (SRSD) and cube root scaled distance (CRSD). In contrast to SRSD scheme, however, the function of maximum charge per delay for CRSD increases without bound after the intersection point of these two functions despite of the similar goodness of fits. To prevent structural damage that may be caused by the excessive charge in the case of CRSD, it is suggested that CRSD be used within a specified distance slightly beyond the intersection point. On the other hand, there are several attempts that predict vibration level(VL) from the peak particle velocity(PPV) or estimate VL based on the scaled distances without considering their frequency spectra. It appears that these attempts are conducted in blasting contracts only for the purpose of satisfying the environment-related law, which mainly deals with the annoyance aspects of noises and vibrations in human life. But, in principle there could no correlation between peaks of velocity and acceleration over entire frequency spectrum. Therefore, such correlations or estimations should be conducted only between the waves with the same or very similar frequency spectra. Finally, it is a known fact that structural damage due to ground vibration is related to PPV level, the safety level criteria for structures should be defined by allowable PPV levels together with their zero crossing frequencies (ZCF).

Effective Fungicides on Control of Stem and Root Rot of Paprika Caused by Nectria haematococca (Nectria haematococca에 의한 착색단고추 줄기 및 과실썩음병의 약제방제)

  • Jee Hyeong-Jin;Shim Chang-Ki;Ryu Kyoung-Yul;Nam Ki-Woong
    • Research in Plant Disease
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    • v.11 no.2
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    • pp.179-184
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    • 2005
  • A previous study reported that the stem and root rot of paprika (Capsicum annum L. var, grossum) caused by Nectria haematococca became a threat to safe cultivation of the plant in the country. However, no strategies for control the disease have been suggested. In this study, fungicides registered for pepper were screened to evaluate their control effects on the disease. Among fungicides tested, prochloraz manganase complex com pletely suppressed mycelial growth of the pathogen at 10 ppm a.i. tebuconazole, benomyl, and carbendazim $\cdot$kasugamycin also effectively inhibited mycelial growth of the fungus. However, kresoxim-methyl and triflox ystrobin did not suppress mycelial growth but significantly suppressed conidial germination of the fungus. Azoxystrobin, benomyl, prochloraz, tebuconazol, and carbendazim$\cdot$ kasugamycin were also effective to retard conidial germination. In vivo tests, tebuconazole strongly inhibited the plant growth even at 16,000x (15.6 ppm a.i.), while others did not induce chemical injury at 4,000x or 8,000x when drenched into a rockwool cube. In a greenhouse test, prochloraz manganase complex at 125 ppm a.i. (4,000x) showed highest control value by $89.9\%$. Other fungicides thiophanate-methylthiram, axozystrobin, trifloxystrobin, and benomyl presented $60-80\%$ control value in the hydroponic cultivation system. However, application time and interval remained to be investigated for identify maximum residue limit.

Effects of Environmental Substrate Composition on the Growth and Yield of Hydroponically Grown Tomato (토마토 양액재배시 배지 환경조성이 생육 및 생산성에 미치는 영향)

  • Lee, Jaesu;Lee, Hyundong;Lee, Sanggyu;Kwak, Kangsu;Kim, Balgeum;Kim, Taehyun;Baek, Jeonghyun;Rho, Siyoung;Hong, Youngsin
    • Journal of Environmental Science International
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    • v.28 no.9
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    • pp.729-735
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    • 2019
  • The aim of this study was to determine the effects of different compositions of environmental substrates on hydroponic tomato cultivation. Three different substrates were used in coir chip:dust (v/v=50:50; CP1), coir chip:dust (v/v=80:20; CP2), and rock wool cube with CP2 (CPR). The amount of irrigation during the cultivation period was 190 mL/(plant time) in all substrates. The pH and EC were 5.8-6.2 and 2.6-2.9 dS/m, respectively. The drainage rate in CP1 was 31%, in CP2 was 36%, and in CPR was 29%. The growth of tomato plants in terms of height was higher in CP1 and CPR. The leaf area was greater in CP2. The fresh and dry weights were greater in CP2 and CPR treatments. The net photosynthesis in CP2 ($19.31{\mu}mol\;CO_2/m^2s$) and root activity in CP2 were higher among all three treatments. The soluble solid content of fruit was not significantly different among treatments. The yield per plant in CP2 and CPR treatments was 17% greater than the yield per plant in CP1. Therefore, the most suitable substrate for hydroponic tomato cultivation is the substrate mixed with coir chip:dust (v:v=80:20; CP2), i.e., CPR.

Control of Phythophthora capsici and Residual Characteristics by the Pesticides Tank-Mixed in Tomato Hydroponic Culture System (농약의 양액 탱크내 혼합처리에 의한 토마토 역병 방제 효과 및 잔류 특성)

  • Ihm, Yang-Bin;Kyung, Kee-Sung;Kim, Cban-Sub;Park, Byung-Jun;Lee, Jung-Sup
    • The Korean Journal of Pesticide Science
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    • v.7 no.4
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    • pp.264-270
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    • 2003
  • To control effectively and safely Phytophthora root rot caused by Phytophthora capsici on tomato in hydroponic culture, tank-mixing method was considered with two pesticides, metalaxyl copper oxychloride 50% WP and dimethomorph dithianon 38% WP. Forty days after transplanting of tomato seedlings, 4 mL of sporangia of P. capsici (about 25 sporangi/mL) per plot was inoculated around tomato plant roots, and at 5 days after inoculation, the pesticides tank-mixed at three dilution levels, 12,500, 25,000 and 50,000, were drenched 1, 2 or 3 times per plot on the culture cube every 15 days for metalaxyl copper oxychloride 50% WP and every 10 days for dimethomorph dithianon 38% WP. During the drenching period, the residue levels of metalaxyl and dimethomorph in hydroponic culture solution were similar to the initial levels but the level of dithianon was drastically decreased from one day after tank-mixing. In tomato drenched with metalaxyl copper oxychloride 50% WP, metalaxyl was detected $0.02\sim0.04$ mg/kg in all diluted plots. Dimethomorph was detected $0.012\sim0.021$, $0.001\sim0.006$ and $0.001\sim0.003$ mg/kg in 12,500, 25,000 and 50,000 times diluted plots, respectively, while dithianon was detected 0.005, 0.003 mg/kg in 12,500 and 50,000 times diluted plots, respectively. The detection levels of three pesticides were far below compared with the levels of Korean MRLs. Incidences of Phytophthora root rot were not found in all the plots, but phytotoxic responses were recognized in the 12,500 times diluted plots of both pesticides. Based on the above results, the drenching of the culture solution tank-mixed with these pesticides could be recommended as a very safe and effective method to control Phytophthora root rot in tomato in hydroponic culture.

Experimental Study of the Effect of Vibration on the Geomunoreum Lava Tube System in Jeju (제주 거문오름 용암동굴계의 진동영향에 관한 실험적 연구)

  • Song, Jae-Yong;Lee, Geun-Chun;Ahn, Ung-San;Lim, Hyun-Muk;Seo, Yong-Seok
    • The Journal of Engineering Geology
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    • v.30 no.3
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    • pp.327-345
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    • 2020
  • The effects of ground vibration on lava tubes during construction were studied to aid design of management and preservation measures for lava tubes. Ground conditions were assessed by RMR (Rock mass rating) and Q-system classifications for the Geomunoreum lava tubes, and vibration velocity was measured during in situ blasting tests in the Manjanggul and Yongcheondonggul lava tubes. Results indicate that the higher the rock quality, the greater the effect of vibration, although there is no clear linear relationship due to ground heterogeneity. A relationship derived between vibration velocity (PPV) and intensity (dB(V)) on the basis of blasting tests indicates that a vibration level of < 0.285 cm/sec meets the regulatory limit of 0.371 cm/sec and 65 dB(V) during daytime, and 0.285 cm/sec and 60 dB(V) during night. For blasting vibrations, square- and cube-root scaled distances are linearly correlated, with R2 ≥ 0.76. On the basis of this correlation, explosive-charge weights meeting the 0.2 cm/sec vibration criterion for cultural heritage were estimated to be 2.88 kg at 50 m distance, and 11.52 kg at 100 m.

The Design and Protective Capacity Assessment of the Prefabricated PC Arch Ammo Magazines (아치형 조립식 PC 탄약고 설계 및 방호성능 평가)

  • Park, Jang-Kweon;Lim, Chul-Won;Ryu, Dong-Woo;Son, Ki-Young;Baek, Jong-Hyuk;Park, Young-Jun
    • Journal of the Korea Institute of Building Construction
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    • v.14 no.6
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    • pp.615-621
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    • 2014
  • This study suggests the design and assembly drawing of the prefabricated precast concrete arch ammo magazines using the numerical analysis as well as the explosion verification test. The protective capacity of the proposed magazines is identified with the maximum support rotation angles measured by explosion verification tests according to the U.S. Unified Facility Criteria 3-340-02. Using numerical analysis, it is examined that oval-type members are better than the semi-circle ones in terms of protective capacity. Based on this numerical results, the design and assemble drawing for the prefabricated precast concrete arch ammo magazine are developed. It is identified that the structure constructed by invented design and assembly drawing has enough protective capacity against blast pressure caused by 133.75kg TNT explosion. The detonation point cannot be open due to the military security. In sum, it could be concluded that the ammo magazine proposed in this study has reliable protective capacity with enough redundancy. The redundancy means that there are more economic design approach with reducing the curved wall thickness.

Acceptance and Preference of Vegetables in Menus for Middle School Students (중학생의 채소류에 대한 기호도 및 메뉴 선호도 조사)

  • Park, So-Hyun;Kim, Mi-Jung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.12
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    • pp.1660-1666
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    • 2008
  • The purpose of the study was to investigate the basic data that could make out a menu reflected by students' preference to increase the intake of vegetable food through the cooking method of favorite vegetables. For the investigation, 585 middle school students in Seoul and Ansan area were surveyed. In the preference of food items, the meat food was more preferred to the vegetable food. Also, the reasons that students do not eat vegetable provided were 'bad taste' and 'unfavorite vegetable'. The preference analysis for vegetable showed that stem and leaf vegetables, root vegetables and fruits & vegetables were in the order of perilla leaver, celery and cabbage, sweet potato, potato, and dried radish cube and tomato, sweet pumpkin and cucumber, respectively. The preference was three kinds of vegetables that were more delicious than frequently eaten in home. The preference analysis for cooking method of vegetables showed that stem and leaf vegetables, root vegetables and fruits & vegetables were in the order of boiled rice, soup/stew, and salads, boiled rice, fried food and salads, salad, soups/stew and raw seasoned vegetables, respectively. Therefore, this study was conducted in order to increase the vegetable intake. According to the results of this study, it should be needed to develop menus integrating vegetables and its cooking methods that students preferred and disliked are needed.