• Journal of Korean Society of Steel Construction
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• v.18 no.2
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• pp.191-201
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• 2006

New design equations for calculating the lateral-torsional buck ling moment resistances of stepped I-section beams with/without continuous lateral top-flange bracing subjected to a point load, a series of point loads, and a uniformly distributed load, are suggested based on the results of elastic finite-element analyses. The new equations presented in this study are compared with the current moment gradient modifiers presented by other researchers and specifications. Although the study paper presents mainly stepped-beam cases subjected to a point load and a uniformly distributed load. The proposed equations include the length-to-height ratio effects for stepped beams with continuous lateral top-flange bracing. The new moment gradient correction factors could be easily used to calculate the lateral-torsional buckling moment resistance of stepped I-beams.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1658-1663
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• 2006

Panax notoginseng (Buck) F.H chen. root (PNS) is used as a therapeutic agent to stop haemorrhages and a tonic to promote health in Korean and Chinses medicine. The pharmacokinetic profiles of the main PNS are still not accurately investigated. Our preliminary aim is to elucidate the pharmacokinetics features of the PNS in rats. Objective of this study is to determine whether PNS affects hepatic microvascular dysfunction elicited by gut ischemia and reperfusion (I/R), since gut I/R causes hepatic microvascular dysfunction, and to investigate the role of nitric oxide (NO). No has been found to be a modulator of the adhesive interactions between platelet and endothelial cells. Male Wistar rats were exposed to 30 min of gut ischemia followed by 60 min of reperfusion. Intravital microscopy was used to monitor the number of non-perfused sinusoids (NPS). In another set of experiments, PNS (1 g/kg pre day intragastrically) was administered to rats for 7 days. In some experiments, dexamethasone (ST) (2 mg/kg per day intravenously) was administered. In control rats, gut I/R elicited increases in the number of NPS, and plasma TNF-${\alpha}$ and ALT activities, and these changes were mitigated by the pretreatment with PNS. Pretreatment with an No synthase inhibitor diminished the protective effects of PNS on the increase in NPS and plasma TNF-${\alpha}$ levels, but not its effect on the increase in plasma ALT activities. Pretreatment with PNS increased plasma nitrite/nitrate levels. The responses caused by gut I/R were attenuated by the pretreatment with ST. Pretreatment with an NO synthase inhibitor did not affect the effect of ST. These results suggest that PNS attenuates the gut I/R-induced hepatic microvascular dysfunction and inflammatory responses such as TNF-${\alpha}$ production in the early phase via enhancement of NO production, and sequential hepatocellular damage via its anti-inflammatory effect like corticosteroid effect.

• Archives of Hand and Microsurgery
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• v.23 no.4
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• pp.296-300
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• 2018

Penile shaft reconstruction requires adequate soft tissue characteristics as well as constant vascular pedicles when considering a perforator flap. The free flap technique using various donor sites and regional conventional and perforator flaps have been utilized for penile shaft reconstruction. Still, the free flap techniques include challenging surgical procedures in addition to postoperative management. The regional flap can be applied to limited defects due to the size and shape. We performed the bilateral superficial external pudendal artery (SEPA) perforator flaps in order to reconstruct a circumferential penile shaft defect. The circumferential wound has noted necrotic tissue involving superficial (Dartos) fascia. We underwent debridement, preserving deep (Buck's) fascia and corpus spongiosum. Thereafter, the soft tissue defect was covered with bilateral SEPA perforator flaps. The patient has been observed for 27 months, showing penile resilience without deformity or wound-related problems.

• Journal of IKEEE
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• v.23 no.1
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• pp.254-260
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• 2019

The failure rate of bidirectional dc-to-dc converter is predicted through the failure mode and effect analysis (FMEA) and the fault-tree analysis (FTA) considering the operational risk. In order to increase the driving voltage of the electric vehicle efficiently, the bidirectional converter is attached to the front of the inverter. It has a boost mode for discharging battery power to the dc-link capacitor and a buck mode for charging the regenerative power to the battery. Based on the results of the FMEA considering the operating characteristics of the bidirectional converter, the fault-tree is designed considering the risk of the converter. After setting the design parameters for the MCU for the electric vehicle, we analyze the failure rate of the capacitor due to the output voltage ripple and the inductor component failure rate due to the inductor current ripple. In addition, we obtain the failure rate of major parts according to operating temperature using MIL-HDBK-217F. Finally, the failure rate and the mean time between failures (MTBF) of the converter are predicted by reflecting the part failure rate to the basic event of the fault-tree.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.1
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• pp.99-105
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• 2019

OBC for battery charging of electric vehicles mainly consist of two stages including PFC circuit and isolated DC-DC converter circuit. In general, a non-isolated boost converter is used as the PFC circuit, and a resonant converter capable of ZVS (zero voltage switching) is used as the isolated DC-DC converter. In this paper, we propose an OBC composed of isolated current-fed type PFC circuit and buck DC-DC converter. The proposed OBC is easy to configure the circuit and controller, and can cope with a wide output range. In order to verify the validity of the proposed circuit, a prototype 3.3 ㎾ class prototype was fabricated. As a result, the maximum efficiency and the maximum power factor of 99.2% were confirmed under the operational stability and rated load conditions at the output voltage of 150V ~ 400V.

• Journal of Convergence for Information Technology
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• v.11 no.6
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• pp.7-13
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• 2021

In this paper, the function of starting the negative voltage used in the IT equipment when it is generated and the method of controlling it using a microcontroller for the function to detect the overload and respond to it are presented. To do this, the limitations of the existing negative voltage generation circuit and the problems that occur during overload were analyzed, and a circuit that detects and controls the overload condition without a separate current sensing circuit was presented. In order to confirm the effect of the proposed method, an experiment was conducted by configuring an experimental circuit. As a result of the experiment, compared to the existing negative voltage generation circuit, which falls into a latch-up state when overloaded and enters a dangerous state, the proposed circuit detects this, stop the operation of the circuit, and informs the user of such an abnormal state to take action. have. In addition, since the starting point of the circuit is determined according to the system state, the experimental result was confirmed that the starting time was significantly shortened by about 23% compared to the time switch method.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.5
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• pp.117-122
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• 2022

In this study, Electromagnetic Induction Power Generation (EMG) is a structure consisting of a stator and a permanent magnet rotor, and is a method that enables power generation by using the kinetic energy of the human arm. Among them, the axial flux permanent magnet (AFPM) technique is a method that can act sensitively to the kinetic energy of the arm at a slow speed of the human body, and has a simple structure and can be designed and manufactured with an ultra-small size. Under the conditions of size of ø46×11mm, rotation speed of 7Hz (420rpm), output voltage 0.4VAC, output current 4.5mA, and output power 30mW were measured and analyzed the same as the target specification. Therefore, the purpose of this study is to study the power generation of the pendulum applying the AFPM (Axial Flux Permanent Magnet) technique to charge power to smart devices with kinetic energy of the human body.

• Korean Journal of Animal Reproduction
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• v.10 no.1
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• pp.109-120
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• 1986

This study was conducted to define the effect of addition of lysolecithin (LC) and 20% v/v rabbit serum to sperm preincubation medium on the induction of acrosome reaction (AR) an fertilizing ability in vitro of LG-added sperm. Ejaculated rabbit sperm from New Zealand White buck was washed once by centrifugation, then preincubated for 2 or 4 hrs in a chemically defined medium (DM), DM plus 20% rabbit serum or BSA-free DM plus 20% rabbit serum at 37$^{\circ}C$ water bath or CO2 incubator. At the end of preincubation LC was added to the preincubated sperm, which was stained at 0.5 to 4 hr later and examined for AR and sperm motility. For in vitro fertilization, gametes were coincubated in DM up to 24 hrs and thereafter fertilized embryos were incubated in BSM -II up to 48 hrs. Addition of LC to 4-hr preincubated sperm was more effective for the AR and sperm motility than that to 2-hr preincubated sperm and optimal concentration of LC for AR was about 80${\mu}$g/ml. A significant increase in AR occured from 20 to 30 min. after addition of 80 to 100${\mu}$g/ml in 4-hr preincubated sperm. BSA-free DM plus 20% rabbit serum showed a higher AR and sperm motility than those of DM plus 20% rabbit serum in LC-added sperm after 4-hr preincubation. The incidence of AR after 4-hr preincubation and at 30 min after 60${\mu}$g/ml LC addition varied greatly among individual bucks. Sixty ${\mu}$g/ml LC-added sperm showed a slight high cleavage rate over control levels, but 100${\mu}$g/ml LC-added sperm showed lower cleavage rate rather than 60${\mu}$g/ml LC. It is concluded that optimal concentration of LC for high AR induction and sperm motility in 4-hr preincubated sperm was about 80${\mu}$g/ml, but 60${\mu}$g/ml level was more useful for in vitro fertilization.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.3
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• pp.185-191
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• 1974

Incubation and pot studies were conducted with upland soils for a study on determination of the lime requirement based on exchangeable alumium content. The results obtained are as follows; 1. Results of chemical analysis of upland soils show that pH varies from 5.0 to 5.4, and exchangeable Al moves with the range of 1.3-3.0m.e/100gr. Exchangeable Al decreases with years of cultivation. 2. Incubation studies shows that on acid mineral soils almost all exchangeable Al, on average 95% was neutralized with the lime to neutralized 100% exchangeable Al. On volcanic ash soil, however, only 65.5% was neutralized with the lime estimated to neutralize the equivalent of 200% exchangeable Al. The latter has required more lime. 3. The pH of mineral soils is on the average increased from an initial 5.2 to 6.3 when 95% of exchangeable Al is neutralized, whereas that on volcanic ash soil is increased from an initial 5.3 to 5.5 only when lime is applied at rate to neutralize the equivalent of 200% exchangeable Al. 4. A high correlation coefficient (r=0.99) was obtained between exchangeable Al and exchangeable acidity. This indicates that exchangeable acidity is primarly a result of exchangeable Al. 5. In pot experiments with soybean cultivated on one of the hill land soils (Songjoong soil) the application of fused phosphate and triple superphosphate based on a 5% saturation rate ($P_2O_5$ 32.1 kg/10a) showed that the liming factor for calculation of the optimum lime requirements based on exchangeable acidity was 0.594 for fuses phosphate or 1.132 for tripple superphosphate, and optimum pH is approximately 6.0 and optimum neutralization rate of exchangeable Al is 80-90%.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1411-1415
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• 2008

The purpose of the present study was to determine the onset of breeding season, the occurrence of silent and true heats and the duration of estrus in female Markhoz goats of the Kurdistan province in Iran. Ten, 3 years-old Markhoz does with an average weight of $34.05{\pm}2.62kg$ and with one kidding record, were used. The goats were maintained in an open barn under constant nutritional levels and natural photoperiod. One aproned buck was used twice a day every 12 h to detect estrus from mid August to early January. For the determination of the onset of reproductive activity as well as occurrence of silent heat, blood samples were collected every 10 days, from the beginning of the experiment. After $2^{nd}$ standing heat, blood samples were obtained twice a week in order to assess luteal activity and the length of estrous cycles. In this study, estrous behavior was observed including sniffing, vocal exchange, following courtship, flehman, standing heat and mounting. The results of the progesterone assay indicated that in this goat silent heats occur mostly in the early breeding season. The first standing heat was observed in mid-October which was considered as the onset of the breeding season. Duration of the estrous cycle and estrus was recorded as being $20.93{\pm}1.56days$ and $38.86{\pm}15.19h$, respectively. The correlation coefficient between length of daylight and occurrence of estrus was negative (r = -0.470) but not significant (p>0.05). The data showed that there was no significant effect of body weight on estrous cycles (first, second and third) and estrous periods (first, second, third and fourth). Progesterone levels were not significantly different in the first, second and third estrous cycles at days 0, 4, 10, 12, 14 and 19. The results of progesterone assay during the estrous cycle indicate that follicular and luteal phases last 4-5 and 14-15 days, respectively and the concentration of serum progesterone in these phases was $0.88{\pm}0.08$ and $7.44{\pm}0.26ng/ml$, respectively. The study concluded that Markhoz does could be considered as a breed with a short breeding season and an optimal estrous activity in autumn.