• Horticultural Science & Technology
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• v.31 no.4
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• pp.423-428
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• 2013

Although closed soilless culture is useful for saving water and fertilizers with minimizing environmental pollution, adequate management of nutrient solutions is still not stabilized in greenhouse cultivation. In order to investigate the problems occurred in closed soilless culture of Paprika (Capsicum annuum L., cv. Fiesta), we compared ion balance, fruit yield, and the water and fertilizer use efficiencies in the closed system with those in the open system. The plants were grown in rockwool culture with a nutrient solution of EC $2.5dS{\cdot}m^{-1}$. After 4 weeks of treatment, individual ratio of $NO{_3}^-$, $K^+$, $Ca^{2+}$, and $Mg^{2+}$ to total ion concentrations ($meq{\cdot}L^{-1}$) decreased from the initial value, especially the biggest decrement was observed in $K^+$, and on the other hand, $SO{_4}^{2-}$, $Cl^-$, and $Na^+$ were accumulated in the closed system. Yields after four-time harvests were 19% higher in the open system than in the closed system. Total volume of water used per unit area ($m^2$) in the open system was 20% higher, but the total water use per fruit was not significantly different between the two systems, while t total fertilizer use per fruit was 78% higher in the closed system. Amount of marketable fruits was not significantly different between the two systems. We concluded that the increase in $K^+$ supply and the replenishment of recycled nutrient solution every four weeks were required for preventing the imbalance or depletion of nutrients in the close soilless culture of paprika plants to get more balanced nutrient composition during whole cultivation period.

• Steel and Composite Structures
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• v.22 no.4
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• pp.797-820
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• 2016

This paper simulates the hysteretic behavior of steel reinforced recycled concrete (SRRC) columns under cyclic loads using OpenSees software. The effective fiber model and displacement-based beam-column element in OpenSees is applied to each SRRC columns. The Concrete01 material model for recycled aggregate concrete (RAC) and Steel02 material model is proposed to perform the numerical simulation of columns. The constitutive models of RAC, profile steel and rebars in columns were assigned to each fiber element. Based on the modelling method, the analytical models of SRRC columns are established. It shows that the calculated hysteresis loops of most SRRC columns agree well with the test curves. In addition, the parameter studies (i.e., strength grade of RAC, stirrups strength, steel strength and steel ratio) on seismic performance of SRRC columns were also investigated in detail by OpenSees. The calculation results of parameter analysis show that SRRC columns suffered from flexural failure has good seismic performance through the reasonable design. The ductility and bearing capacity of columns increases as the increasing magnitude of steel strength, steel ratio and stirrups strength. Although the bearing capacity of columns increases as the strength grade of RAC increases, the ductility and energy dissipation capacity decreases gradually. Based on the test and numerical results, the flexural failure mechanism of SRRC columns were analysed in detail. The computing theories of the normal section of bearing capacity for the eccentrically loaded columns were adopted to calculate the nominal bending strength of SRRC columns subjected to vertical axial force under lateral cyclic loads. The calculation formulas of horizontal bearing capacity for SRRC columns were proposed based on their nominal bending strength.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.7B
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• pp.695-705
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• 2002

In this paper, we propose a simple open loop transmit diversity (TD) scheme for the wideband code division multiple access (W-CDMA) systems in Rician multipath fading channels such as rural area or satellite channels where line-of-sight (LOS) paths are in presence. The proposed scheme does not require any pre-processing of transmit data, resulting in simpler structure as compared to conventional closed loop transmit adaptive array (TxAA) and open loop space-time transmit diversity (STTD). We analytically derive the probability density function of signal-to-noise ratio at the Rake receiver output and the uncoded bit error rate performance of the proposed scheme. Extensive simulation is Performed to verify the analytical performance of the proposed scheme under typical Rician multipath fading channel environments. Moreover, comparative results with the conventional TxAA and STTD are also provided. Simulation results show that the proposed scheme shows slightly better performance than the conventional open loop STTD under the channels with very weak LOS components, however, it significantly outperforms the STTD under the channels with dominant LOS components, and achieves a close performance of ideal closed loop TxAA.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.27 no.3
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• pp.292-300
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• 2023

Backgrounds/Aims: Current literature presents limited data regarding outcomes following conversion at the time of minimally invasive pancreaticoduodenectomy (MI-PD). Methods: The National Cancer Database was queried for patients who underwent pancreaticoduodenectomy. Patients were stratified into three groups: MI-PD, converted to open pancreaticoduodenectomy (CO-PD), and open pancreaticoduodenectomy (O-PD). Multivariable modeling was applied to compare outcomes of MI-PD and CO-PD to those of O-PD. Results: Of 17,570 patients identified, 12.5%, 4.2%, and 83.4% underwent MI-PD, CO-PD, and O-PD, respectively. Robotic pancreaticoduodenectomy (R-PD) resulted in a higher lymph node yield (n = 23.2 ± 12.2) even when requiring conversion (n = 22.4 ± 13.2, p < 0.001). Margin positivity was higher in the CO-PD group (26.6%) than in the MI-PD group (21.3%) and the O-PD (22.6%) group (p = 0.017). Length of stay was shorter in the MI-PD group (laparoscopic pancreaticoduodenectomy 10.4 ± 8.6, R-PD 10.6 ± 8.8) and the robotic converted to open group (10.7 ± 6.4) than in the laparoscopic converted to open group (11.2 ± 9) and the O-PD group (11.5 ± 8.9) (p < 0.001). After adjusting for patient and tumor characteristics, both MI-PD (odds ratio = 1.40; p < 0.001) and CO-PD (odds ratio = 1.24; p = 0.020) were significantly associated with an increased likelihood of long-term survival. Conclusions: CO-PD does not negatively impact perioperative or oncologic outcomes.

• Korean Journal of Plant Resources
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• v.27 no.6
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• pp.701-706
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• 2014

Three highbush blueberries (Vaccinium corymbosum cvs. Bluecrop, Coville, and Northland) grown in an open field and in a rain shelter were compared to evaluate the potential benefits of rain-sheltering systems on growth and fruit quality. Shrubs grown in rain shelter flowered 5-14 days earlier and were in full bloom earlier than those in the open field. All three cultivars set fruit by nearly 90% of flowers when they were grown in the open field, but was markedly reduced when they were grown in the rain shelter, to approximately 50% for 'Bluecrop' and 'Coville'. Fruit sets ratio of 'Northland' grown in the in the rain shelter was 14.5. Fruit from greenhouse-grown 'Northland' were larger, heavier, and had more seeds per berry. Soluble sugar content (SSC) of fruits varied both with the cultivars and growing conditions. SSC of fruits grown in the greenhouse was higher in 'Bluecrop' compared to that grown in the field, but this pattern was reversed in 'Northland'. Titratable acid was significantly higher in fruits from rain shelter-grown shrubs of both 'Bluecrop' and 'Northland' than in fruits from open field-grown shrubs (P < 0.05), although there was no difference in TA with respect to growing conditions for 'Coville'. The number of seed per fruit, fruit length and diameter, weight, SSC, and TA were similar in 'Coville' shrubs grown in the open field and the rain shelter. Fruit firmness of 'Bluecrop', 'Coville', and 'Northland' was higher in the rain shelter than in the open field. 'Coville' and 'Northland' fruits harvested in the open field had higher blue chroma than those harvested in the rain shelter. However, this pattern was reversed for 'Bluecrop'. On the whole, sheltering from rain affected most fruit characteristics of the three cultivars differently. Therefore, suitable blueberry cultivars for the rain shelter should be chosen by purpose.

• Advances in pediatric surgery
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• v.2 no.1
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• pp.8-16
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• 1996

Laparoscopic appendectomy is relatively well-established as an alternative to conventional open appendectomy by many laparoscopic surgeons. However, experience in the pediatric population remains limited. Over a period of 2 years, a total of 155 pediatric patients with acute appendicitis or complicated appendicitis were studied to compare laparoscopic and open appendectomies in childhood. Laparoscopic appendectomy was attempted in 49 patients and completed in 48 patients(98.0%). Open appendectomy was performed in 107 patients. The severity of disease, age, and male to female ratio were similar in both groups. The operation time was shorter in the laparoscopic group than open group but the difference was not significant statistically($43.7{\pm}11.3$ minutes versus $49.0{\pm}21.4$ minutes, p=0.066). In the laparoscopic group, the mean duration of surgery for the former half patients was significantly longer than for the latter half($49.6{\pm}9.2$ minutes versus $38.1{\pm}10.3$ minutes, p=0.001). The mean number of doses of analgesia required postoperatively was significantly less in patients undergoing laparoscopic appendectomy($2.4{\pm}1.8$ versus $3.3{\pm}2.5$, p=0.021). There were only 2(4.2%) wound infections after laparoscopic appendectomy compared with 10(9.3%) complications including 7 wound infections, 1 intestinal obstruction, and 2 pulmonary complications after open appendectomy, but the difference was not significant(p=0.614). Patients undergoing laparoscopic appendectomy had a shorter period of hospitalization($3.2{\pm}2.2$ days versus $6.4{\pm}1.6$ days. p=0.001). The present study suggests that laparoscopic appendectomy shortens operating time and hospital stay with diminished postoperative pain. Laparoscopic appendectomy in children offers advantages over open appendectomy as noted in adults. The authors consider laparoscopic appendectomy to be the reasonable alternative to open appendectomy in children.

• Journal of Powder Materials
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• v.28 no.1
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• pp.7-12
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• 2021

The change in the open porosity of bulk graphite as a function of the uniaxial molding pressure during manufacturing is studied using artificial graphite powder. Subsequently, the graphite is impregnated to determine the effect of the open porosity on the impregnation efficiency and to improve the density of the final bulk graphite. Bulk graphite is manufactured with different uniaxial molding pressures after mixing graphite powder, which is the by-product of processing the final graphite products and phenolic resin. The bulk density and open porosity are measured using the Archimedes method. The bulk density and open porosity of bulk graphite increase as the molding pressure increases. The open porosity of molded bulk graphite is 25.35% at 30 MPa and 29.84% at 300 MPa. It is confirmed that the impregnation efficiency increases when the impregnation process is performed on a specimen with large open porosity. In this study, the bulk density of bulk graphite molded at 300 MPa is 11.06% higher than that before impregnation, which is the highest reported increase. Therefore, it is expected that the higher the uniaxial pressure, the higher the density of bulk graphite.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.1
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• pp.252-264
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• 2023

This paper proposes a design of a dual-band band-pass filter that integrates a λg/2 open SIR structure, a transmission line, and a fork-type structure with symmetric and asymmetric open stubs. To obtain the dual-band effect, the proposed filter uses the SIR structure and adjusts the impedance ratio of the SIR structure. Therefore, the position of the harmonics of the filter is shifted through the adjustment of the impedance ratio, and this can obtain a double-band effect. In order to obtain the dual-band characteristics, the dual-band effect is obtained by inserting a open stub between the SIR structures with the SIR structure divided in half. In addition, the second frequency response is obtained by adjusting the length of the open symmetrical stub in the fork-shaped structure. The asymmetrical open stub in the fork form achieves optimum bandwidth by adjusting the length. Therefore, the first center frequency of the proposed band-pass filter is 5.896 GHz and the bandwidth is 13.6 %. At this time, the measurement results are 0.13 dB and 33.6 dB. The second center frequency is 5.906 GHz and the bandwidth is 13.6 %. At this time, the measurement results are 0.15 dB and 19.8 dB. The reason is that when the impedance ratio (Δ) is higher than 1, the position of the harmonic is shifted to a lower frequency band. However, if the impedance ratio (Δ) is lowered by one step, the position of harmonics will move to a higher frequency band. The function of the filter designed using these characteristics can be obtained from the measurement result. The proposed band-pass filter has no coupling loss and no via energy concentration loss because there is no coupling structure of input/output and no via hole. Therefore, system integration is possible due to its excellent performance, and it is expected that dedicated short-range communication (DSRC) system applications used in traffic communication systems will be possible.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.274-274
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• 2017

Temperature has an adverse effect for potential growth and development of Codonopsis lanceolata. The present study examined the responses of growth, yield and mineral element contents under temperature variables in C. lanceolata. Plant height exhibited the best result as being 2 m or higher the open field culture, while the growth is the most restricted in the $30^{\circ}C$. The open field culture also had the largest number of leaves in the early stage of growth. The number of leaves and the height tended to be increased with the temperature of $20^{\circ}C$ and $25^{\circ}C$. The number of branches showed no significance as 32 branches and 26 branches in open field culture and $20^{\circ}C$, respectively. The smallest number of branches was observed in the $30^{\circ}C$ with 15 branches. The leaf color recorded the lowest value in the open field culture unlike the growth above the ground. But all other temperature had no significance with the leaf color value between 50.0 and 52.6. The elevated temperature induced the thinner and shorter diameter and length of root. However, the root diameter was not significantly changed with the change of 1.8 cm and 2.1 cm at open field culture, with $20^{\circ}C$ and $25^{\circ}C$, respectively. The fresh weights of the primary root and lateral roots were 6.3 g and 3.1 g, respectively, at the high temperature. The result showed the thickening of the lowest part under the ground as restricted. The fresh weights of the main root and lateral root were the highest on the open field culture, 20.6 g and 12.2 g, respectively. The contents of cellulose were the highest as 4.41% in the $20^{\circ}C$, followed by the open field culture, $25^{\circ}C$ and $30^{\circ}C$. The higher temperature reduced the contents of cellulose. Moreover, P showed higher ratio in the high temperature while Ca and Mg exhibited the higher ratio towards the low temperature. On the contrary, minor quantity (less than 1%) of mineral nutrients was observed towards all temperature variables.

• Journal of Intelligence and Information Systems
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• v.15 no.2
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• pp.15-31
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• 2009

The next generation IT environment is expected to be an open computing environment based on Grid computing technologies, which allow users to access to any type of computing resources through networks. The open computing environment has benefits in aspects of resource utilization, collaboration, flexibility and cost reduction. Due to the variation in performance of open computing resources, however, resource allocation simply based on users' budget and time constraints often fails to meet the Service Level Agreement(SLA). This paper proposes the Mean-Absolute Deviation(MAD) portfolio optimization approach, in which service brokers consider the uncertainty of performance of resources, and compose resource portfolios that minimize the uncertainty. In order to investigate the effect of this approach, we simulate an open computing environment with varying uncertainty levels, users' constraints, and brokers' optimization strategies. The simulation result concludes threefolds. First, the MAD portfolio optimization improves the success ratio of delivering the required performance to users. Second, the success ratio depends on the accuracy in predicting the variability of performance. Thirdly, the measured variability can also help service brokers expand their service to cost-critical users by discounting the access cost of open computing resources.