• Steel and Composite Structures
• /
• v.46 no.6
• /
• pp.793-804
• /
• 2023

In this study, cyclic loading tests were conducted to assess the seismic performance of cast-in-place (CIP) concrete-filled hollow core precast concrete columns (HPCC) constructed using steel ducts and rubber tubes. The outer shells of HPCC, with a hollow ratio of 47%, were fabricated using steel ducts and rubber tubes, respectively. Two combinations of shear studs & long threaded bars or cross-deformed bars & V-ties were employed to ensure the structural integrity of the old concrete (outer shell) and new CIP concrete. Up to a drift ratio of 3.8%, the hysteresis loop, yielding stiffness, dissipated energy, and equivalent damping ratio of the HPCC specimens were largely comparable to those of the solid columns. Besides the similarities in cyclic load-displacement responses, the strain history of the longitudinal bars and the transverse confinement of the three specimens also exhibited similar patterns. The measured maximum moment exceeded the predicted moment according to ACI 318 by more than 1.03 times. However, the load reduction of the HPCC specimen after reaching peak strength was marginally greater than that of the solid specimen. The energy dissipation and equivalent damping ratios of the HPCC specimens were 20% and 25% lower than those of the solid specimen, respectively. Taking into account the overall results, the structural behavior of HPCC specimens fabricated using steel ducts and rubber tubes is deemed comparable to that of solid columns. Furthermore, it was confirmed that the two combinations for securing structural integrity functioned as expected, and that rubber air-tubes can be effectively used to create well-shaped hollow sections.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.36 no.4
• /
• pp.1-20
• /
• 2023

Objectives: The object of this study was to observe the complex anti-climacterium potentials of Yuklinzu aqueous extracts (YLZ), using bilateral ovariectomy (OVX) female ddY mice similar to women postmenopausal symptoms, as including cardiovascular diseases, obesity, hyperlipidemia, osteoporosis and hepatic steatosis. Methods: In order to evaluate anti-climacterium effects of YLZ, six groups of mice were used; sham control, OVX control, 17β-estradiol, YLZ 500, 250 and 125 mg/kg treated groups. Since 28 days after bilateral OVX surgery, YLZ were administered orally for 84 days, once a day. And then we evaluated anti-climacterium effects divided into five categories; estrogenic effects, anti-obesity, hypolipidemic effects, hepatoprotective effects and anti-osteoporotic effects. The results of YLZ were compared with 17β-estradiol 0.03 ㎍/head/day subcutaneous treated OVX mice. Results: As a result of OVX, obvious changes related to the estrogen-deficient menopausal symptoms - obesity, hyperlipidemia, hepatic steatosis and osteoporosis were displayed in mice. However, these menopausal symptoms induced by OVX were significantly inhibited by 84 days of consecutive treatment of 17β-estradiol, YLZ 500, 250 and 125 mg/kg, respectively. Especially, YLZ showed obvious dose-dependent inhibitory activities on the OVX-induced climacterium changes in mice, and YLZ 500 mg/kg showed comparable inhibitory effects against menopausal symptoms in comparison with those of 17β-estradiol 0.03 ㎍/head/day subcutaneous treatment. Conclusions: The results suggest that oral administration of YLZ 500, 250 and 125 mg/kg has obvious dose-dependent favorable anti-climacterium effects in OVX mice. Especially, YLZ 500 mg/kg showed comparable inhibitory effects against menopausal symptoms in comparison with those of 17β-estradiol 0.03 ㎍/head/day subcutaneous treatment.

• Korean Journal of Radiology
• /
• v.22 no.6
• /
• pp.912-921
• /
• 2021

Objective: To compare the performance of the deep learning-based lesion detection algorithm (DLLD) in detecting liver metastasis with that of radiologists. Materials and Methods: This clinical retrospective study used 4386-slice computed tomography (CT) images and labels from a training cohort (502 patients with colorectal cancer [CRC] from November 2005 to December 2010) to train the DLLD for detecting liver metastasis, and used CT images of a validation cohort (40 patients with 99 liver metastatic lesions and 45 patients without liver metastasis from January 2011 to December 2011) for comparing the performance of the DLLD with that of readers (three abdominal radiologists and three radiology residents). For per-lesion binary classification, the sensitivity and false positives per patient were measured. Results: A total of 85 patients with CRC were included in the validation cohort. In the comparison based on per-lesion binary classification, the sensitivity of DLLD (81.82%, [81/99]) was comparable to that of abdominal radiologists (80.81%, p = 0.80) and radiology residents (79.46%, p = 0.57). However, the false positives per patient with DLLD (1.330) was higher than that of abdominal radiologists (0.357, p < 0.001) and radiology residents (0.667, p < 0.001). Conclusion: DLLD showed a sensitivity comparable to that of radiologists when detecting liver metastasis in patients initially diagnosed with CRC. However, the false positives of DLLD were higher than those of radiologists. Therefore, DLLD could serve as an assistant tool for detecting liver metastasis instead of a standalone diagnostic tool.

• Clinical and Experimental Reproductive Medicine
• /
• v.51 no.1
• /
• pp.57-62
• /
• 2024

Objective: The purpose of this study was to use a mouse model to investigate the blastocyst formation rate in vitrified-warmed embryos derived from vitrified-warmed oocytes. Methods: Metaphase II oocytes obtained from BDF1 mice were vitrified and warmed, followed by fertilization with epididymal sperm. On day 3, a total of 176 embryos, at either the eight-cell or the morula stage, were vitrified-warmed (representing group 1). For group 2, 155 embryos at the same developmental stages were not vitrified, but rather were directly cultured until day 5. Finally, group 3 included day-5 blastocysts derived from fresh oocytes, which served as fresh controls. The primary outcome measured was the rate of blastocyst formation per day-3 embryo at the eight-cell or morula stage. Results: The rates of blastocyst formation per day-3 embryo were comparable between groups 1 and 2, at 64.5% and 69.7%, respectively (p>0.05). The formation rates of good-quality blastocysts (expanded, hatching, or hatched) were also similar for groups 1 and 2, at 35.5% and 43.2%, respectively (p>0.05). For the fresh oocytes (group 3), the blastocyst formation rate was 75.5%, which was similar to groups 1 and 2. However, the rate of good-quality blastocyst formation in group 3 was 57.3%, significantly exceeding those of group 1 (p=0.001) and group 2 (p=0.023). Conclusion: Regarding developmental potential to the blastocyst stage, vitrified-warmed day-3 embryos originating from vitrified-warmed oocytes demonstrated comparable results to non-vitrified embryos from similar oocytes. These findings indicate that day-3 embryos derived from vitrified-warmed oocytes can be effectively cryopreserved without incurring cellular damage.

• Animal Bioscience
• /
• v.37 no.2
• /
• pp.210-217
• /
• 2024

Objective: This study investigated the efficacy of different concentrations of gelatin supplementation in long-term semen extender on boar semen quality during storage for 10 days at 17℃. Additionally, oxytocin was added to stored semen to enhance fertility. Methods: In Experiment 1, boar semen was collected, diluted with gelatin at concentrations between 0% and 2.5% (w/v) and mixed with a semen extender. Then, it was kept in a refrigerator at 17℃ and stored for 10 days. In Experiment 2, the sperm quality was examined after adding 0, 5, and 10 IU oxytocin per artificial insemination dose to the most effective semen extender from Experiment 1 and placing it in a refrigerator at 17℃ for 10 days. In Experiment 3, the fertility potential in terms of non-return rate and litter size was determined using the most effective solid-stored semen supplemented with oxytocin. Results: The results indicated that sperm quality decreased with increasing storage time (p<0.05). The sperm quality in terms of total motility, progressive motility, and viable sperm with intact acrosomes and high mitochondrial potential was the highest with 1.5% gelatin supplementation (p<0.001) on all days of storage. Treatment with oxytocin did not affect sperm quality (p>0.05). The non-return rate and litter size after insemination with semen supplemented with 1.5% gelatin and 10 IU of oxytocin after 8 to 10 days of storage were comparable to those of the control group (p>0.05). Conclusion: A semen extender as a solid medium supplemented with 1.5% gelatin successfully preserved boar semen for a long storage duration. Treatment with oxytocin did not affect sperm quality. In addition, the fertility capacity using 1.5% gelatin with 10 IU oxytocin and stored for 8 to 10 days was acceptable and comparable to that of short-term storage.

• Annals of Hepato-Biliary-Pancreatic Surgery
• /
• v.28 no.1
• /
• pp.48-52
• /
• 2024

Backgrounds/Aims: Splenectomy is the most frequently performed procedure as definitive management or as part of shunt surgery or devascularization in portal hypertension. Splenectomy is technically challenging because of the frequent coexistence of multiple collateral varices, splenomegaly, poor liver function, and thrombocytopenia. Early arterial ligation and late mobilization (EALDEM) is the traditional method for splenectomy in portal hypertension. Early spleen mobilization offers good control of the hilum. We aim to compare the effect of the early mobilization and delayed arterial ligation (EMDAL) technique with that of the conventional splenectomy technique in patients with portal hypertension. Methods: During the study period from September 2011 to September 2022, 173 patients underwent surgical intervention for portal hypertension at our institution. Among these patients, 114 underwent the conventional method of splenectomy (early arterial ligation and late splenic mobilization) while 59 underwent splenectomy with the EMDAL technique. Demographics were compared between the two groups. Intraoperative and postoperative outcomes were analyzed using the Mann-Whitney test in each group. A minimum follow-up of 12 months was performed in each group. Results: Demographics and type of surgical procedure were comparable in the two surgical method groups. Median blood loss was higher in the conventional group than in the EMDAL method. The median duration of surgery was comparable in the two surgical procedures. Clavien-Dindo grade III/IV complications were reported more frequently in the conventional group. Conclusions: The splenic hilum can be controlled well and bleeding can be minimised with early mobilization and delayed arterial ligation.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2002.10a
• /
• pp.11-16
• /
• 2002

The production of Portland cement involves maximum use of resources and energy, which leads to destruction of tile ecological environment, raising in serious environmental issues such as acid rain and the greenhouse effect. In order to combat the arising problems associated with Portland cement, it thus is necessary that a non-clinker cement should be developed. In this study, non-clinker cement is produced by blending granulate blast furnace slag with phosphogypsum as main materials, and small amounts of hydrate lime or waste lime as activators. This paper aims to investigate compressive strength according to various condition of mixing ratio, blame, W/C ratio and curing temperature. Compressive strength of non-clinker cement increases continuously according to increase in curing age and blain. Although the compressive strength is fairly comparable to that of OPC in the early curing age, it reaches a higher lever in the later age than that of OPC due to the optimum mixing ratio and the continuous reaction of slag and phosphogypsum. Results obtained from this study have shown that non-clinker cement could be used as a replacement of OPC.

• Elastomers and Composites
• /
• v.52 no.4
• /
• pp.303-308
• /
• 2017

In this study, finite element modeling and material property tests are performed for the finite element analysis of rubber isolator parts which support the engine and isolate the vibration. As a result of the P direction analysis of the rubber isolator parts, the static stiffness in the P direction was 44.2 kg/mm, which is well within the error of 5% as compared with the test result of 46.1 kg/mm. The static stiffness of the rubber isolator parts in the Q direction was calculated to be 7.9 kg/mm, which is comparable to the test result of 8.6 kg/mm, with an error of less than 8%. As a result of the analysis on the Z direction, the static stiffness was calculated as 57.7 kg/mm, and the test results were not available. Through this study, it is expected that the time and cost for prototype development can be reduced through nonlinear finite element analysis for rubber isolator parts.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.19 no.6
• /
• pp.1382-1390
• /
• 1995

Electronic Speckle Pattern Interferometry (ESPI) with a CW laser, a video system and an image processor was utilized to measure the in-plane displacement. Unlike traditional strain gauges or Moire method. ESPI method measure the in-plane displacement on real time with out any surface preparation on surface attachment. The specimen has a crack of 10*0.1 mm in the middle of plate and strain gauge was also attached on that surface to compare with ESPI method. This study reveled the ESPI method to measure the displacement and distribution of strain in the specimen. It was shown in tensile tests that the measurement by ESPI method was comparable with strain gauge.

• Journal of Environmental Science International
• /
• v.9 no.6
• /
• pp.483-488
• /
• 2000

In this study, the distribution characteristics of volatile organic compounds (VOCs) were investigated on the seasonal basis across spring, summer, and fall during the year of 1998. According to this analysis, most VOC species investigated exhibited strong temporal trends. Over diurnal scale, there distribution characteristics were affected by seasonal factors strongly. While they showed high day/night ratio pattern during spring, the pattern was reversed during fall. When the seasonal mean values were compared between the two seasons, the spring values were systematically higher than their counterparts in most cases. In addition when our VOC measurement date were compared with those reported from elsewhere, we were able to conclude that the VOC levels in the study area are comparable to the level weakly impacted by the regional emissions of VOCs. Although our data are not sufficient enough to systematically explain the atmospheric distribution and behavior of VOCs, the findings of strong correlations among some of VOC species suggests strong need for investigating their interactions in the earth\`s atmosphere.