• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.48.4-48
• /
• 2002

1) A method to realize active vibration control using SAC and acceleration type sensor is proposed from the viewpoint of practical application. 2) The use of acceleration type sensor makes it easy to satisfy ASPR condition in applying SAC system and to implement sensor in practical mechanical system. 3) Results were confirmed through numerical simulation of 1 DOF vibration system.

• Korean Journal of Food Science and Technology
• /
• v.31 no.3
• /
• pp.739-745
• /
• 1999

This study was carried out to investigate the oligosaccharide and amino acid utilization by mixed cultures during soy yogurt fermentation. Three types soy yogurt were prepared by fermenting with Lactobacillus acidophilus and Streptococcus thermophilus, Streptococcus thermophilus and Saccharomyces uvarum, Lactobacillus acidophilus and Saccharomyces uvarum. The utilized amount of oligosaccharide and amino acid was determined by HPLC during the fermentation period. The oligosaccharide and amino acid utilization efficiency of S. thermophilus and Sac. uvarum was greater than the other mixed cultures. It was found that Sac. uvarum produced enzymes which can convert oligosaccharide and common sugars in soy milk into glucose, galactose and fructose which can be fermented by L. acidophilus and S. thermophilus, and in turn stimulated acid production and amino acid utilization of the latter.

• ETRI Journal
• /
• v.35 no.6
• /
• pp.1152-1155
• /
• 2013

A cost-effective and simple solder on pad (SoP) process is proposed for a fine-pitch microbump interconnection. A novel solder bump maker (SBM) material is applied to form a 60-${\mu}m$ pitch SoP. SBM, which is composed of ternary Sn3.0Ag0.5Cu (SAC305) solder powder and a polymer resin, is a paste material used to perform a fine-pitch SoP through a screen printing method. By optimizing the volumetric ratio of the resin, deoxidizing agent, and SAC305 solder powder, the oxide layers on the solder powder and Cu pads are successfully removed during the bumping process without additional treatment or equipment. Test vehicles with a daisy chain pattern are fabricated to develop the fine-pitch SoP process and evaluate the fine-pitch interconnection. The fabricated Si chip has 6,724 bumps with a 45-${\mu}m$ diameter and 60-${\mu}m$ pitch. The chip is flip chip bonded with a Si substrate using an underfill material with fluxing features. Using the fluxing underfill material is advantageous since it eliminates the flux cleaning process and capillary flow process of the underfill. The optimized bonding process is validated through an electrical characterization of the daisy chain pattern. This work is the first report on a successful operation of a fine-pitch SoP and microbump interconnection using a screen printing process.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.25 no.3
• /
• pp.131-136
• /
• 2013

The present study has conducted cycle design and control technology of a water source VRF heat pump system. Previously, study of a simultaneous heating and cooling in an air source VRF heat pump system has been conducted. However, performance data and design methods for simultaneous heating and cooling in a water source VRF heat pump system are limited in the literature, due to various system parameters and operating conditions. In this study, the operating characteristics and performances of a simultaneous heating and cooling heat pump system are carried out, in simultaneous operation modes. Control logics of an EEV are developed for flow rate control to the outdoor unit, and are verified. When the control logics are applied, the simultaneous cooling and heating performances are sufficiently achieved, and system COPs are increased by up to 23.4%.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.29 no.3
• /
• pp.152-158
• /
• 2016

The bonding characteristics of MLCCs (multi layer ceramic capacitor, C1608) lead-free solder (SAC305) joints were evaluated through thermal shock test ($-40^{\circ}C{\sim}125^{\circ}C$, total 1,800 cycle). After the test, IMCs( intermetallic compounds) growth and cracks were verified, also shear strengths were measured for degradation of solder joints. In addition, The thermal stress distributions at solder joints were analyzed to compare the solder joints changes before and after according to thermal shock test by FEA (finite elements analysis). We considered the effects of IMCs growth at solder joints. As results, the bonding characteristics degradation was occurred according to initial crack, crack propagations and thermal stress concentration at solder-IMCs interface, when the IMCs grown to solder inside.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.30 no.3
• /
• pp.136-145
• /
• 2017

Objectives: The aim of this study was to report a case of 43 year-old patient, diagnosed with missed abortion who previously failed to do spontaneous gestational sac expulsion in spite of 2 week-expectant-method, eventually succeeded with Traditional Korean Herb Medicine (TKHM) treatment only. Methods: In transabdominal sonography, gestational sac was not present at week 8. Due to the possibility of effect of medication on future pregnancy and post-surgery complications, D&C (Dilation & Curettage) as well as any other treatment was not done. Instead, she presented to our clinic. A combination of 2 main TKHMs was prescribed with 120-150 cc/dose (2 times per day for a week) : Gunggi-tang for helping expulsion of the dead fetus and placenta, and Wooseul-tang for treating retained placenta. Results: On day 6 of TKHM treatment, initiation of placenta expulsion was done. From day 8, hemorrhage started, lasting for 6 days. On day 10, placenta was expelled. On day 13, gestational sac and placenta were completely expelled. No infection, delayed bleeding, or pain was observed. After bleeding stopped, menorrhea started from week 7. Conclusions: This report implies a potential of TKHM as an optional and safe medication for the natural expulsion of conceptus in missed abortion.

• Kosin Medical Journal
• /
• v.33 no.3
• /
• pp.358-368
• /
• 2018

Objectives: To identify the relationship between surgical success rate and preoperative nasal mucosal thickness around the lacrimal sac fossa, as measured using computed tomography. Methods: We reviewed 33 eyes from 27 patients who underwent endoscopic dacryocystorhinostomy after diagnosis of primary nasolacrimal duct obstruction and who were followed-up with for at least six months between 2011 and 2014. We measured preoperative nasal mucosal thickness around the bony lacrimal sac fossa using computed tomography and analyzed patient measurements after classifying them into three groups: the successfully operated group, the failed operation group, and the non-operated group. Results: Surgery failed in six of the 33 eyes because of a granuloma at the osteotomy site and synechial formation of the nasal mucosa. The failed-surgery group showed a clinically significantly greater decrease in nasal mucosal thickness at the rearward lacrimal sac fossa compared with the successful-surgery group. However, nasal mucosal thickness of fellow eyes (i.e., non-operated eyes) was not significantly different between the two groups, and the location of the uncinate process did not appear to influence mucosal thickness. In the failed group, posteriorly located mucosal thickness of operated eye fossa was thinner than that of the non-operated eyes, but not significantly so. Conclusions: Our results from this quantitative anatomical study suggest that nasal mucosal thickness is a predictor of endoscopic dacryocystorhinostomy results.

• Journal of the Microelectronics and Packaging Society
• /
• v.29 no.3
• /
• pp.55-61
• /
• 2022

In this study, properties of Pb-free solder joints which were combined using Sn-3.0Ag-0.5Cu (SAC305) Pb-free solder with a mid-temperature type of melting temperature and Sn-57Bi-1Ag Pb-free solder with a low-temperature type of melting temperature were reported. Combined Pb-free solder joints were formed by reflow soldering processes with ball grid array (BGA) packages which have SAC305 solder balls and flame retardant-4 (FR-4) printed circuit boards (PCBs) which printed Sn-57Bi-1Ag solder paste. The reflow soldering processes were performed with two types of temperature profiles and interfacial properties of combined Pb-free solder joints such as interfacial reactions, formations of intermetallic compounds (IMCs), diffusion mechanisms of Bi, and so on were analyzed with the reflow process conditions. In order to compare reliability characteristics of combined Pb-free solder joints, we also conducted thermal shock test and analyzed changes of mechanical properties for joints from a shear test during the thermal shock test.

• Development and Reproduction
• /
• v.22 no.3
• /
• pp.263-273
• /
• 2018

Aquaporin (AQP) 3, a facilitated transporter of water and glycerol, expresses in placenta and fetal membranes, but the detailed localization and function of AQP3 in placenta remain unclear. To elucidate a role of AQP3 in placenta, we defined the expression and cellular localization of AQP3 in placenta and fetal membranes, and investigated the structural and functional differences between wild-type and AQP3 null mice. Gestational sacs were removed during mid-gestational period and amniotic fluid was aspirated for measurements of volume and composition. Fetuses with attached placenta and fetal membranes were weighed and processed for histological assessment. AQP3 strongly expressed in basolateral membrane of visceral yolk sac cells of fetal membrane, the syncytiotrophoblasts of the labyrinthine placenta and fetal nucleated red blood cell membrane. Mice lacking AQP3 did not exhibit a significant defect in differentiation of trophoblast stem cells and normal placentation. However, AQP3 null fetuses were smaller than their control litter mates in spite of a decrease in litter size. The total amniotic fluid volume per gestational sac was reduced, but the amniotic fluid-to-fetal weight ratio was increased in AQP3 null mice compared with wild-type mice. Glycerol, free fatty acid and triglyceride levels in amniotic fluid of AQP3 null mice were significantly reduced, whereas lactate level increased when compared to those of wild-type mice. These results suggest a role for AQP3 in supplying nutrients from yolk sac and maternal blood to developing fetus by facilitating transport of glycerol in addition to water, and its implication for the fetal growth in utero.

• The Korean Journal of Food And Nutrition
• /
• v.28 no.5
• /
• pp.745-751
• /
• 2015

This study was performed to investigate the quality characteristics such as pH, total acidity, browning index, 5-hydroxymethylfurfural (5-HMF), fructose, S-allyl-L-cysteine (SAC), total polyphenol, and DPPH radical scavenging activity of aged garlic at different aging temperatures and periods. Aging temperature and period had a significant (p<0.05) effect on the quality characteristics of garlic. The pH in aged garlic significantly (p<0.05) decreased with increasing aging temperatures and periods, while the total acidity, browning index, and 5-HMF levels increased. The 5-HMF levels in garlic aged at 60 and $70^{\circ}C$ increased from 0.08~3.30 and from 0.05~106.07 mg/100 g, respectively. The fructose content in garlic aged at $60^{\circ}C$ gradually increased from 0.77 to 14.57%, while that of garlic aged at $70^{\circ}C$ increased from 1.07 to 19.75% until day 30, after which it decreased. The SAC level in raw garlic was 47.09 mg/100 g. The SAC contents of aged garlic differed significantly according to aging temperature and period. The SAC levels in garlic aged at $60^{\circ}C$ and $70^{\circ}C$ were in the range of 15.28~100.5 and 12.41~85.55 mg/100 g, respectively. The total polyphenol contents of garlic aged at $60^{\circ}C$ and $70^{\circ}C$ were 6.01 and 6.67 fold higher, respectively, than those in raw garlic. The DPPH radical scavenging activity of aged garlic also showed a tendency to increase during aging.