• Reproductive and Developmental Biology
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• v.33 no.3
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• pp.153-156
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• 2009

The purpose of this study was to assess for re-breeding concentrate period in postpartum in milking cows. The 48 cows aged $3.5{\sim}5.5$ years and of $400{\sim}600\;kg$ body weight were examined every 3rd day from 15 to 36 day postpartum. Blood samples for progesterone and estradiol $17{\beta}$ hormone analyses were withdrawn from the coccygeal vein every third day until the end of the experiment. The ovarian follicular numbers were verified and measured using a multi frequency probe. The least squares means are presented for each day by GLM of SAS. The results showed that ovary lengths (right ovary; $1.64{\pm}0.62\;cm$, left ovary; $1.44{\pm}0.46\;cm$) were similar in right and left ovary activity level during estrous cycle of postpartum cows. We were judged completed uterus on day at $2.31{\pm}0.17\;cm$ level of cervix diameter. And we were monitoring started at $6.44{\pm}2.03\;cm$ from day 15 after postpartum. The results showed that mean plasma concentration of progesterone (3.28 ng/ml) in large follicle gradually increased days 30 in postpartum. And, monitoring of estradiol 176 (22.18 pg/ml) hormone during postpartum period would be useful to predict the ovarian and uterus activity for re-breeding in postpartum milking cows. From these results, we conclude that cervix diameter (mean: 2.31 cm) was very important for reproductive organ recovery standard level of postpartum milking cows, hormone secretion level ($P_4$: 3.28 ng/ml, $E_2$: 22.18 pg/ml) and body condition score ($2.5{\sim}2.75$) level about 30 days in postpartum period.

• Journal of Korea Foundry Society
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• v.20 no.2
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• pp.104-109
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• 2000

Three different white cast irons alloyed with Cr, V, Mo and W were prepared in order to study their abrasion wear behavior in as-cast and heat-treated conditions. The specimens were produced using a 15㎏-capacity high frequency induction furnace. Melts were super-heated to $1600^{\circ}C$, and poured at $1550^{\circ}C$ into Y-block pepset molds. Three combinations of the alloying elements were selected so as to obtain the different types of carbides : 3%C-10%Cr-5%Mo-5%W(alloy No. 1: $M_7C_3$ and $M_6C$), 3%C -10%V-5%Mo-5%W(alloy No. 2: MC and $M_2C$) and 3%C-17%Cr-3%V(alloy No. 3: $M_7C_3$ only). A scratching type abrasion test was carried out in the states of as-cast(AS), homogenizing(AH), air-hardening(AHF) and tempering(AHFT). First of all, the as-cast specimens were homogenized at $950^{\circ}C$ for 5h under the vacuum atmosphere. Then, they were austenitized at $1050^{\circ}C$ for 2h and followed by air-hardening in air. The air-hardened specimens were tempered at $300^{\circ}C$ for 3h. 1 ㎏ load was applied in order to contact the specimen with abrading wheel which was wound by 120 mesh SiC paper. The wear loss of the test piece(dimension: $50{\times}50{\times}5$ mm) was measured after one cycle of wear test and this procedure was repeated up to 8 cycles. In all the specimens, the abrasion wear loss was found to decrease in the order of AH, AS, AHFT and AHF states. Abrasion wear loss was lowest in the alloy No.2 and highest in the alloy No.1 except for the as-cast and homogenized condition in which the alloy No.3 showed the highest abrasion wear loss. The lowest abrasion wear loss of the alloy No.2 could be attributed to the fact that it contained primary and eutectic MC carbides, and eutectic $M_2C$ carbide with extremely high hardness. The matrix of each specimen was fully pearlitic in the as-cast state but it was transformed to martensite, tempered martensite and austenite depending upon the type of heat-treatment. From these results, it becomes clear that MC carbide is a significant phase to improve the abrasion wear resistance.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.5
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• pp.436-442
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• 2020

ESS(energy storage system) has recently become an important power source in various areas due to increased renewable energy resources. The more ESS is used, the less the effective capacity of the ESS. Therefore, it is important to manage the remaining useful lifetime(RUL). RUL can be checked regularly by inspectors, but it is common to be monitored and estimated by an automated monitoring system. The accurate state estimation is important to ESS operator for economical and efficient operation. RUL estimation model usually requires complex mathematical calculations consisting of cycle aging and calendar aging that are caused by the operation frequency and over time, respectively. A lightweight RUL estimation model is required to be embedded in low-performance processors that are installed on ESS. In this paper, a lightweight ESS RUL estimation model is proposed to operate on low-performance micro-processors. The simulation results show less than 1% errors compared to the original RUL model case. In addition, a performance analysis is conducted based on ATmega 328. The results show 76.8 to 78.3 % of computational time reduction.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.5
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• pp.1203-1212
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• 2013

In this paper, an intra prediction hardware architecture is proposed to reduce computational complexity of intra prediction in HEVC decoder. The architecture uses shared operation units and common operation units and adopts a fast smoothing decision algorithm and a fast algorithm to generate coefficients of a filter. The shared operation unit shares adders processing common equations to remove the computational redundancy. The unit computes an average value in DC mode for reducing the number of execution cycles in DC mode. In order to reduce operation units, the common operation unit uses one operation unit generating predicted pixels and filtered pixels in all prediction modes. In order to reduce processing time and operators, the decision algorithm uses only bit-comparators and the fast algorithm uses LUT instead of multiplication operators. The proposed architecture using four shared operation units and eight common operation units which can reduce execution cycles of intra prediction. The architecture is synthesized using TSMC 0.13um CMOS technology. The gate count and the maximum operating frequency are 40.5k and 164MHz, respectively. As the result of measuring the performance of the proposed architecture using the extracted data from HM 7.1, the execution cycle of the architecture is about 93.7% less than the previous design.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.221-226
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• 2006

This study is about backwash condition and membrane fouling at continuous filtration process in ballast water treatment. Displayed result that handle particle contaminant and hydrospace organism included a number of ballast that is happened in ship using automatic back washing filter. Reason that removes first contaminant that is included in number of ballast is that heighten processing effect of after processing process of the filter. Another advantage is to drop off the solids with controlling revolution of drum screen in pretreatment filtration process. The capacity of pilot plant was $10m^3/h$. The result of the test, Backwash cycle time and duration time and a signification effect on the efficiency of system and backwash Backwash duration time was determined to be fixed in 6 seconds of the system with more than 95% removal rate, It needed 1hour backwash frequency. Filtration system removal aquatic organism over $70{\mu}m$ in ballast water. This study shows that the filtration treatment system has a potential for the treatment of ballast water.

• Journal of Korea Water Resources Association
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• v.31 no.3
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• pp.317-326
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• 1998

Water consumption characteristics on the northern part of Seoul were analyzed using wavelet transform with a base function of Coiflets 5. It turns out that long term evolution mode detected at 212 scale in 1995 was in a shape of hyperbolic tangent over the entire period due to the development of Sanggae resident site. Furthermore, there was seasonal water demand having something to do with economic cycle which reached its peak at the ends of June and December. The amount of this additional consumption was about $1,700\;\textrm{cm}^3/hr$ on June and $500\;\textrm{cm}^3/hr$ on December. It was also shown that the periods of energy containing sinusoidal component were 3.13 day, 33.33 hr, 23.98 hr and 12 hr, respectively, and the amplitude of 23.98 hr component was the most humongous. The components of relatively short frequency detected at $2^i$[i = 1,2,…12] scale were following Gaussian PDF. The most reliable predictive models are multiple AR[32,16,23] and ARMA[20, 16, 10, 23] which the input of temperature from the view point of minimized predictive error, mutual independence or residuals and the availableness of reliable meteorological data. The predicted values of water supply were quite consistent with the measured data which cast a possibility of the deployment of the predictive model developed in this study for the optimal management of water supply facilities.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.23 no.1
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• pp.32-48
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• 2018

The mechanisms of $CH_4$ uptake into and release from the ocean are not well understood due mainly to complexity of the biogeochemical cycle and to lack of regional-scale and/or process-scale observations in the marine boundary layers. Without complete understanding of oceanic mechanisms to control the carbon balance and cycles on a various spatial and temporal scales, however, it is difficult to predict future perturbation of oceanic carbon levels and its influence on the global and regional climates. High frequency, high precision continuous measurements for carbon isotopic compositions from dissolved $CH_4$ in the surface ocean and marine atmosphere can provide additional information about the flux pathways and production/consumption processes occurring in the boundary of two large reservoirs. This paper introduces recent advances on optical instruments for real time $CH_4$ isotope analysis to diagnose potential applications for in situ, continuous measurements of carbon isotopic composition of dissolved $CH_4$. Commercially available, three laser absorption spectrometers - quantum cascade laser spectroscopy (QCLAS), off-axis integrated cavity output spectrometer (OA-ICOS), and cavity ring-down spectrometer (CRDS) are discussed in comparison with the conventional isotope ratio mass spectrometry (IRMS). Details of functioning and performance of a CRDS isotope instrument for atmospheric ${\delta}^{13}C-CH_4$ are also given, showing its capability to detect localized methane emission sources.

• Horticultural Science & Technology
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• v.31 no.5
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• pp.652-655
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• 2013

Natural habitats of weedy melons were distributed on the islands along and on the west and south coasts of Korean peninsula including Boryeong, Seosan (Taean), Seocheon, Okgu, Buan, Gochang, Yeonggwang, Muan, Shinan, Haenam, Jindo, Wando, Goheung, Yeocheon, Hadong, Namhae, Goseong, Tongyeong, Geoje, and Jeju islands including Jeju city, Bukjeju-gun and Nam Jeju-gun. Weedy melons were found growing wildly in or around the cultivated lands in these regions. Natural habitats of weedy melons were in and around the cultivated lands. Weedy melon plants were found most often in soybean fields, followed by fields of mungbean, sweet potato, pepper, sesame, cotton, and peanuts. The plants were also found growing wild in foxtail millet fields, rice paddy levees along the streams, upland field edges, watermelon fields, corn fields, vegetable gardens near farmhouse, orange fields, compost piles, fallow fields, roadside and home gardens. They inhabited in sunny and a little dry spaces in relatively low-height crop plant fields in general. The time of fruit maturity was from early July to late October with the most frequency in September according to post survey answer. Fruits dropped off from the fruit stalk when matured. This phenomenon was thought beneficial for perpetuation in the wild. The fruits were being used commonly for food and toys for children. It was thought that weedy melons were perpetuating through the cycle of human and animal feeding of the fruits, human and animal droppings, often mixed in compost, and application of the compost to crop fields by human.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.356-362
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• 2000

Yakju(rice wine) was sterilized with high-voltage square-wave pulses of $1\;{\mu}s$ duration at various electric field strengths and frequencies on a serial multiple electrode pulsed electric field(PEF) treatment system consisted of 7 electrodes connected in series. The initial microbial counts of Yakju were $1.88{\times}10^3{\sim}2.13{\times}10^4$ CFU/mL for total aerobes, $1.55{\times}10^3{\sim}2.85{\times}10^4$ CFU/mL for lactic acid bacteria and $1.72{\times}10^3{\sim}2.39{\times}10^4$ CFU/mL for yeasts. The sterilization of microorganisms in Yakju was a first order reaction and the sterilization effect increased as the field strength and the frequency increased. The $D_{Hz}-value$ and the $D_{PEF}-value$ decreased with the electric field strength. Yeast showed lower $D_{PEF}-value$ than bacteria. Lactic acid bacteria showed lower $D_{PEF}-value$ than general aerobic bacteria under the electric field strength below 30 kV/cm, but higher ones under that above 40 kV/cm. The $Z_{PEF}-value$ of general aerobic bacteria, lactic acid bacteria and yeast in Yakju were 39.4, 49.3 and 47.6 kV/cm, respectively. The PEF sterilization resulted in less changes in color and sensory properties than heat sterilization, and the PEF treated Yakju showed superior quality to the heat treated one. The commercial sterilization of Yakju was accomplished with 2-cycle treatment on the tested serial PEF treatment system.

• Journal of the Korean GEO-environmental Society
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• v.16 no.7
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• pp.35-42
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• 2015

Grouting method has been widely used for the ground improvement and stabilization: mostly to block or control the ground water in the early years and to improve the ground, repair the structure in recent years, ever increasing its use. Despite many advantages so far, the existing grouting method also has some shortcomings including uncertain permeation of grouting with gravity type if the voids between the soil particles are narrow, and problems due to the relaxation of the neighboring ground when injected using injection pressure. As an alternative, a vibration injection method with constant amplitude and frequency has been developed in recent years, with the vibration grouting being reported to have a permeability increasing effect of grout material compared with the positive pressure injection type. Accordingly, the purpose of this study is to investigate the improvement effect of the vibration grouting that applies short-period vibration energy by varying vibration cycle, vibration time and ground conditions to evaluate the strength enhancing effect of grouting materials, expansion effect of grouting body, ground improvement effect of the grouting and the penetration characteristics of the rock joint. The findings of this study show the improved compressive strength of grout, expansion of grouting body and increased penetration rate, according to the vibration compared with non-vibration under the loose soil condition.