• Nuclear Medicine and Molecular Imaging
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• v.41 no.2
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• pp.172-180
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• 2007

Among the nuclear medicine imaging methods available today, $H_2^{15}O-PET$ is most widely used by cognitive neuroscientists to examine regional brain function via the measurement of regional cerebral blood flow (rCBF). The short half-life of the radioactively labeled probe, $^{15}O$, often allows repeated measures from the same subjects in many different task conditions. $H_2^{15}O-$ PET, however, has technical limitations relative to other methods of functional neuroimaging, e.g., fMRI, including relatively poor time and spatial resolutions, and, frequently, insufficient statistical power for analysis of individual subjects. However, recent technical developments, such as the 3-D acquisition method provide relatively good image quality with a smaller radioactive dosage, which in turn results in more PET scans from each individual, thus providing sufficient statistical power for the analysis of individual subject's data. Furthermore, the noise free scanner environment $H_2^{15}O$ PET, along with discrete acquisition of data for each task condition, are important advantages of PET over other functional imaging methods regarding studying state-dependent changes in brain activity. This review presents both the limitations and advantages of $^{15}O-PET$, and outlines the design of efficient PET protocols, using examples of recent PET studies both in the normal healthy population, and in the clinical population.

• Reproductive and Developmental Biology
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• v.30 no.3
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• pp.213-218
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• 2006

This study was conducted to investigate the effect of abnormal ovarian cycle postpartum on subsequent reproductive performance of Holstein cows. The cows were considered to have resumed ovarian cyclicity on the day of ovulation if followed by regular ovarian cycles. Total 58.8 percentage of the cows(l14/194) had normal resumption of ovarian cyclicity(resumption within 40 days after calving), and 41.2%(80/194) had delayed resumption(resumption did not occur until >40 days after calving). Delayed resumption Type I(one or more ovarian cycles with luteal phase >20 days, i.e. prolonged luteal phase; 17.5%) and delayed resumption Type II(first ovulation did net occur until $\geq$40 days after calving, i.e. anovulation 22.7%) were the most common types of delayed resumptions. When compared with cows with a normal ovarian cycle, the cows of delayed resumption Type I had a lower 100 days AI submission conception and pregnancy rates(84.2% vs 40.0%; p<0.01, 24.0% vs 21.4% and 20.2% vs 11.1%, respectively), and longer intervals to first AI and to conception($64.7{\pm}2.79$ days vs $105.7{\pm}7.48$ days and $105.1{\pm}7.16$ days vs $133.7{\pm}11.17$ days, respectively; p<0.01). Similarly, when compared with cows with normal ovarian cycles, the cows of delayed resumption Type II had lower 100 days conception and pregnancy rates(24.0% vs 20.0% and 20.2% vs 16.3%, respectively), and longer intervals to first AI and to conception($64.7{\pm}2.79$ days vs $72.6{\pm}4.45$ days and $105.1{\pm}7.16$ days vs $120.8{\pm}12.33$ days, respectively). In conclusion, abnormal ovarian cycles postpartum adversely affected reproductive performance, including AI submission rate, pregnancy rate, interval to first AI, and calving to conception interval in Holstein cows.

• Journal of agriculture & life science
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• v.46 no.3
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• pp.119-127
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• 2012

For the promotion of the evaporative cooling efficiency of hot air in greenhouse in summer, a fog sprayer consisted of a high volume spraying two-fluid nozzle with turbo fan and a blowing fan was set up at 2.2 m height from bottom of small glass greenhouse and tested to estimate the possibility of the greenhouse cooling. The mean droplet size and the volume sprayed by one of fog sprayer were $29{\mu}m$ and $160m{\ell}/min$. All the droplets sprayed and blown by the fog sprayer were evaporated within 2 m radius. The result from the cooling test that two sprayers set up in glass greenhouse of plane area $228m^2$ was represented lower cooling effect that the temperature and relative humidity of inside air of greenhouse were $28.8^{\circ}C$ and 87.5% when those of outside air of greenhouse were $30.2^{\circ}C$ and 81.2%. Through investigation of literatures and results of the cooling test, it was estimated that the water spraying rate of evaporative cooling of single span greenhouse with 50% light curtain and with air change rate of 1 volume/min was $10m{\ell}/min/m^2$ so that the inside air temperature may cool down $2{\sim}3^{\circ}C$ on the basis of $35^{\circ}C$ atmospheric temperature in summer of south korean area.

• Journal of Soil and Groundwater Environment
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• v.14 no.4
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• pp.33-44
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• 2009

Water curtain of an underground LPG storage cavern is a facility to prevent leakage of high pressure gases, for which groundwater should flow freely towards the cavern and groundwater level also must be stably maintained. In this study, in order to evaluate qualities of seepage water and surrounding groundwater of an underground LPG storage cavern in Yeosu, 4 rounds of samplings, field measurements and laboratory analyses (February, May, August, October of 2007) were conducted. According to field measurements, pH was weak acidic to neutral but it gradually increased with time. Electrical conductivity (EC) of groundwater near a salt stack showed very high values between 10.47 and 38.50 mS/cm. Dissolved oxygen (DO) showed a very wide range of 0.20~8.74 mg/L and a mean of oxidation-reduction potential (ORP) was 159 mV, which indicated an oxidized condition. Levels of $Fe^{2+}$ and $Mn^{2+}$ were mostly less than 3 mg/L. All of seepage waters showed a Na-Cl type while only groundwater near the salt stack showed a Na-Cl type with a high total dissolved solid. The other groundwaters exhibited typical $Ca-HCO_3$ types. Levels of aerobic bacteria were mostly very high (573-39,520 CFU/mL). Based on the analyses of these hydrochemistry and biological characteristics, it is concluded that there are no particular problems in groundwater and seepage water, which not causing a trouble in the cavern operation. However, both for control of bio-clogging and for sustainable operation of the water curtain system, a regular hydrochemical and microbiological monitoring is required for the seepage water and surrounding groundwater.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.3
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• pp.158-169
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• 2019

A probabilistic model that can predict the residual useful lifetime of structure is formulated by using the gamma process which is one of the stochastic processes. The formulated stochastic model can take into account both the sampling uncertainty associated with damages measured up to now and the temporal uncertainty of cumulative damage over time. A method estimating several parameters of stochastic model is additionally proposed by introducing of the least square method and the method of moments, so that the age of a structure, the operational environment, and the evolution of damage with time can be considered. Some features related to the residual useful lifetime are firstly investigated into through the sensitivity analysis on parameters under a simple setting of single damage data measured at the current age. The stochastic model are then applied to the rubble-mound breakwater straightforwardly. The parameters of gamma process can be estimated for several experimental data on the damage processes of armor rocks of rubble-mound breakwater. The expected damage levels over time, which are numerically simulated with the estimated parameters, are in very good agreement with those from the flume testing. It has been found from various numerical calculations that the probabilities exceeding the failure limit are converged to the constraint that the model must be satisfied after lasting for a long time from now. Meanwhile, the expected residual useful lifetimes evaluated from the failure probabilities are seen to be different with respect to the behavior of damage history. As the coefficient of variation of cumulative damage is becoming large, in particular, it has been shown that the expected residual useful lifetimes have significant discrepancies from those of the deterministic regression model. This is mainly due to the effect of sampling and temporal uncertainties associated with damage, by which the first time to failure tends to be widely distributed. Therefore, the stochastic model presented in this paper for predicting the residual useful lifetime of structure can properly implement the probabilistic assessment on current damage state of structure as well as take account of the temporal uncertainty of future cumulative damage.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.46-54
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• 2021

The biological activities of non-edible extracts of asparagus stems and roots were investigated using hot water and ethanol. The highest contents of rutin and total polyphenol were 31.74 mg/g and 20.14 mg GAE/g, respectively, in the stem hot water extract. ABTS and DPPH radical scavenging activities were 541.1±21.0 and 649.5±6.6 ㎍/mL, respectively, in stem hot water extract. All extracts were non-cytotoxic in HepG2 cells, but 200 ㎍/mL stem extracts tended to decrease the viability of RAW 264.7 cells. The highest xanthine oxidase inhibitory activity was 43.68% in the root hot water extract at 200 ㎍/mL. The expression level of MMP-9 was significantly decreased in the asparagus extracts. The highest GGT, AST, and LDH activities showed a concentration-dependent decrease in the stem ethanol extract. In conclusion, the presence of bioactive substances in the non-edible extracts of asparagus was confirmed for the development of extracts with antioxidant, hepatoprotective and anti-gout activities.

• (The) Research of the performance art and culture
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• no.34
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• pp.173-214
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• 2017

This study examines and compares music-related records in the mubo (舞譜; choreography notes) written by Sung Gyeonglin (成慶麟, 1911 - 2008), based on the records of 11 kinds of jeongjae (the music and dance performances at the royal court) found in Lee Byungseong's (李丙星, 1909 - 1960) Changsa and Jungjaecheol (呈才及唱詞綴). Even though these records are personal, they provide valuable information about the mubo of the Iwangjikaakbu (the Royal Music Institute) during the period of Japanese colonization. The eleven kinds types of jeongjae-'Cheoyongmu (處容舞)', 'Hyangryungmu (響鈴舞)', 'Mugo (舞鼓)', 'Bosangmu (寶相舞)', 'Chunangjeon (春鶯?)', 'Gainjeonmokdan (佳人剪牧丹)', 'Suyeonjang (壽延長)', 'Mansumu (萬壽舞)', 'Bongraeeui (鳳來儀)', 'Jangsaengboyeonjimu (長生寶宴之舞)', and 'Musanhyang (舞山香)'-can be largely divided into two types: Dangak (Tang dynasty music) and 'Hyangak (traditional Korean music).' The former is distinguished musically by whether or not the jukganja appears. For the appearance of the jukganja in 'Sujeyongjang', 'Bongraeeui' and 'Jangsaengboyeongjimu', the 'boheojaryung (步虛子令)' was used and given the impressive name of jangchunbullojigok (長春不老之曲).' The term punggyungjigok (豊慶之曲)' was used for music that guides a group dance and dancers. For the latter, hamnyungjigok (咸寧之曲) was performed during the development of the dance, and the pungungyeonghoijigok (風雲慶會之曲) was played at the end of the piece. As for the accompaniment for the jeongjae performed by the Iwangjikaakbu, it is significant that various elaborate names were attached to Sangryungsan, Jungryungsan, Seryungsanm, Garakdeoli, Samhyunhwanip, Yeombulhwanip, and taryung (the traditional Korean ballad), which were all parts of 'Samhyunyoungsanhoesang (靈山會上).' Specifically, the 'Hyangdanggyoju (鄕唐交奏)' in 'Jeongjaemudoholgi' was accompanied by various melodies of the 'Samhyunyoungsanhoesang', which were given extravagant names. These are the personal records of the Iwangjikaakbu mubo that were retained by Lee Honggu (李興九, b. 1940), who owns the 'Hakyeonhwadaehapseolmu.' Among them, the ten kinds of jeongjae found in the notes of Sung Gyeonglin are often referred to as 'mueui (舞儀)' and widely used for research on individual jeongjae performances and the history of their development. The notes of Lee Byungseong have not been investigated thoroughly until now and this is the first study that provides a comparative analysis of the notes of Lee Byungseong and Sung Gyeonglin. This investigation is expected to contribute to the further research and knowledge of the jeongjae performance during the period of Japanese colonization.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.2
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• pp.101-109
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• 2022

The mobility and transport of radioactive cesium are crucial factors to consider for the safety assessment of high-level radioactive waste disposal sites in granite. The retardation of radionuclides in the fractured crystalline rock is mainly controlled by the hydrochemical condition of groundwater and surface reactions with minerals present in the fractures. This paper reports the experimental results of cesium sorption to the Wonju Granite, a typical Mesozoic granite in Korea, performed in an anaerobic chamber that mimics the anoxic environment of a deep disposal site. We measured the rates and amounts of cesium (¹³³Cs) removed by crushed granite samples in different electrolyte (NaCl, KCl, and CaCl₂) solutions and a synthetic groundwater solution, with variations in the initial cesium concentration (10^-5, 5×10^-6, 10^-6, 5×10^-7 M). The cesium sorption kinetic and isotherm data were successfully simulated by the pseudo-second-order kinetic model (r²= 0.99) and the Freundlich isotherm model (r²= 0.99), respectively. The sorption distribution coefficient of granite increased almost linearly with increasing biotite content in granite samples, indicating that biotite is an effective cesium scavenger. The cesium removal was minimal in KCl solution compared to that in NaCl or CaCl₂ solution, regardless of the ionic strength and initial cesium concentration that we examined, showing that K⁺ is the most competitive ion against cesium in sorption to granite. Because it is the main source mineral of K⁺ in fracture fluids, biotite may also hinder the sorption of cesium, which warrants further research.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.2
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• pp.37-45
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• 2022

A simplified model using the lifetime distribution has been presented to estimate the Mean Residual Life (MRL) of rubble-mound breakwaters, which is not like a stochastic process model based on time-dependent history data to the cumulative damage progress of rubble-mound breakwaters. The parameters involved in the lifetime distribution can be easily estimated by using the upper and lower limits of lifetime and their likelihood that made a judgement by several experts taking account of the initial design lifetime, the past sequences of loads, and others. The simplified model presented in this paper has been applied to the rubble-mound breakwater with TTP armor layer. Wiener Process (WP)-based stochastic model also has been applied together with Monte-Carlo Simulation (MCS) technique to the breakwater of the same condition having time-dependent cumulative damage to TTP armor layer. From the comparison of lifetime distribution obtained from each models including Mean Time To Failure (MTTF), it has found that the lifetime distributions of rubble-mound breakwater can be very satisfactorily fitted by log-normal distribution for all types of cumulative damage progresses, such as exponential, linear, and logarithmic deterioration which are feasible in the real situations. Finally, the MRL of rubble-mound breakwaters estimated by the simplified model presented in this paper have been compared with those by WP stochastic process. It can be shown that results of the presented simplified model have been identical with those of WP stochastic process until any ages in the range of MTT F regardless of the deterioration types. However, a little of differences have been seen at the ages in the neighborhood of MTTF, specially, for the linear and logarithmic deterioration of cumulative damages. For the accurate estimation of MRL of harbor structures, it may be desirable that the stochastic processes should be used to consider properly time-dependent uncertainties of damage deterioration. Nevertheless, the simplified model presented in this paper can be useful in the building of the MRL-based preventive maintenance planning for several kinds of harbor structures, because of which is not needed time-dependent history data about the damage deterioration of structures as mentioned above.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.35 no.2
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• pp.23-32
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• 2023

Probabilistic and deterministic analyses are implemented for the armor units of rubble foundation mound of composite breakwaters which is needed to protect the upright section against the scour of foundation mounds. By a little modification and incorporation of the previous empirical formulas that has commonly been applied to design the armor units of foundation mound, a new type formula of stability number has been suggested which is capable of taking into account slopes of foundation mounds, damage ratios of armor units, and incident wave numbers. The new proposed formula becomes mathematically identical with the previous empirical formula under the same conditions used in the developing process. Deterministic design have first been carried out to evaluate the minimum weights of armor units for several conditions associated with a typical section of composite breakwater. When the slopes of foundation mound become steepening and the incident wave numbers are increasing, the bigger armor units more than those from the previous empirical formula should be required. The opposite trends however are shown if the damage ratios is much more allowed. Meanwhile, the reliability analysis, which is one of probabilistic models, has been performed in order to quantitatively verify how the armor unit resulted from the deterministic design is stable. It has been confirmed that 1.2% of annual encounter probability of failure has been evaluated under the condition of 1% damage ratio of armor units for the design wave of 50 years return period. By additionally calculating the influence factors of the related random variables on the failure probability due to those uncertainties, it has been found that Hudson's stability coefficient, significant wave height, and water depth above foundation mound have sequentially been given the impacts on failure regardless of the incident wave angles. Finally, sensitivity analysis has been interpreted with respect to the variations of random variables which are implicitly involved in the formula of stability number for armor units of foundation mound. Then, the probability of failure have been rapidly decreased as the water depth above foundation mound are deepening. However, it has been shown that the probability of failure have been increased according as the berm width of foundation mound are widening and wave periods become shortening.