• Journal of the Korean Society of Visualization
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• v.10 no.1
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• pp.27-33
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• 2012

This paper describes a new design of small-scale horizontal wind blade, called spiral wind turbine blade. Theoretical and numerical approaches on the prediction of aerodynamic performance of the blade have been conducted. A theoretical equation is successfully derived using the angular momentum equation to predict aerodynamic characteristics according to the design shape parameters of spiral blade. To be compared with the theoretical value, a numerical simulation using ANSYS CFX v12.1 is performed on the same design with the theoretical one. Large scale tip vortex is captured and graphically presented in this paper. The TSR-$C_p$ diagram shows a typical parabolic relation in which the maximum efficiency of the blade approximately 25% exists at TSR=2.5. The numerical simulation agrees well with that of the theoretical result except at the low rotational speed region of 0~20 rad/s.

• Journal of Biosystems Engineering
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• v.14 no.4
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• pp.229-241
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• 1989

The purposes of this study were to develop an electronic-hydraulic draft control system for tractor implements, to investigate the control performance of the system and the possibility of adaptation to the conventional tractor. Experiments were carried out to investigate the responses of the system to the step and sinusoidal inputs in draft control. The effects of control mode, hydraulic flow rate, reference deadband, and proportional constant on control performance of the system were investigated. Moreover, the effects of filtering signals from draft sensor were also investigated. The following conclusions were derived from the study; 1. In draft control, there were hunting problems in controlling the implement without filtering the draft signals. Filtering was performed by a control program of electronic controller and the control performance and stability of the system were improved significantly. 2. For the draft control system operated on on-off control mode, draft was controlled within ${\pm}27-{\pm}55kg_f$ to the reference draft when the hydraulic flow rates were 5-15 l/min. For the draft control system operated on PWM control, draft was controlled within ${\pm}27kg_f$ to the reference draft regardless of hydraulic flow rates. 3. In the frequency responses of the draft control system, control performance on PWM control mode was not better than on on-off control mode because of characteristics of hydraulic valve and drafe sensor. As the hydraulic flow rates increased for the system operated on on-off control mode, the corner frequency of amplitude attenuation increased, but the corner frequency of phase-angle change remained nearly the same. But, the system was unstable beyond the frequency of 3.1 rad/s. 4. The electronic-hydraulic hitch control system developed in this study showed superior control performance, stability and convenience compared to conventional mechanical-hydraulic hitch control system. It is considered to be a superior replacement for the conventional mechanical-hydraulic hitch control system.

• Nuclear Engineering and Technology
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• v.7 no.3
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• pp.213-222
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• 1975

Immobilization of the second-cycle radioactive liquid wastes from a Purex process was developed with the blown asphalt (manufactured by Kukdong Shell Oil Company Ltd) to eliminate the possibility that the radioactive materials will be redispersed into the environment. Attempts to incorporate these wastes directly into the asphalt martrices without any pretreatment were not successful, as it was observed that the sulphuric acid in the waste oxidised the asphalt. Hence, the waste was treated with caustic soda and made alkaline prior to bituminization, so that it was found that this pretreatment made the waste compatible to the asphalt matrices. The pure blown asphalt samples irradiated with doses of 4.0$\times$10$^{7}$ rad showed no evidence of volume increase. The suitable temperature for incorporation of the alkaline wastes into blown asphalt was 180-20$0^{\circ}C$. The Products containing 50 wt% salts represented the following good properties viz., volume reduction (about 1.4), homogeneity, teachability etc. During the period of 131 day $s^{l37}$Cs from products containing 40wt% salts was leached at rates ranging from 2.70$\times$10-4 to 8.27$\times$10-4g/cm2_day but the rate for $^{90}$ Sr was lower by one to two orders of magnitude by distilled water. The leaching rates for $^{137}$ Cs and $^{90}$ Sr by sea water were slightly lower than by distilled water. Both of the leaching rates decreased with increasing pH.H.

• The Korean Journal of Mycology
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• v.27 no.2 s.89
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• pp.112-118
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• 1999

Strains of Fusarium oxysporum f. sp. lycopersici isolated from Korea, Japan and U.S.A. were used for electrophoretic karyotype (EK) analysis. Chromosome separations on FastLane agarose gels (FMC BioProducts, Rockland, ME), called pulsed field gel electrophoresis (PFGE), were performed by CHEF-DRII apparatus (Bio-Rad Laboratories, Melville, NY) using TAE as a running buffer. To obtain optimal condition for separation of chromosome sized DNAs, variable running conditions such as field strengths, swithching intervals, and running time were applied in CHEF gel electrophoresis. We were able to resolve 9 to 11 chromosome sized DNAs ranging in size from 0.76 to 6.41 Mb in isolates from Korea and estimate that the total genome size was ranging from 35.29 to 38.92 Mb. Distinct differences in length range and genome size exist among isolates from different countries. Isolates from Japan and U.S.A. were resolved 9 to 11 chromosome sized DNAs ranging in size from 1.24 to 6.85 Mb and estimated that the total genome size was ranging from 35.32 to 43.87 Mb. Isolates from variable provinces in Korea had the same or similar chromosomal polymorphism and showed different chromosomal DNA patterns compared to isolates from the other countries.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10985-10989
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• 2015

Background: The capability for DNA double-strand breaks (DSBs) repair is crucial for inherent radiosensitivity of tumor and normal cells. We have investigated the clinicopathologic significance of DNA repair gene expression in nasopharyngeal (NP) carcinoma. Materials and Methods: A total of 65 NP cancer patients who received radiotherapy were included. The immunopositivity to Ku 70, DNA-PKcs, MRN, RAD50, XRCC4, and LIG4 were examined in all tumor tissues. Results: The patients comprised 42 males and 23 females, with a median age of 56 years (range, 18-84). The expression levels of RAD50 (0,+1,+2,+3) were 27.7%, 32.3%, 21.5%, and 18.5%. LIG4 (${\pm}$) were 43.1% and 56.9% respectively. The 5-year OS rate of patients with LIG4 (${\pm}$) were 90% and 67.9%, respectively (p=0.035). The 5-year TTP rate of patients with LIG4 (${\pm}$) were 75.9%, 55.5%, respectively (P=0.039). Conclusions: Our results suggest the possibility of predicting the radiosensitivity of NP cancer by performing immunohistochemical analysis of LIG4.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.4
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• pp.307-314
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• 2005

After dental implant are planted into their bony site among the various growth factors associated with bone formation. BMP is expressed in the bone surrounding the implant fixture. By taking a close look at BMP2, BMP4 which are growth factors that take put in bone formation, its histologic features and radiographic bone healing patterns we would like to examine the mechanism of osseointegration. We randomly used 8 male and female house rabbit amd used diameter 5 mm height spiral shaped implants(Ostem, Korea) for animal use handled as a resorbable blast machined(RBM) surface and machined surface. 2group were formed and each group had RBM surface and machined surface implant or a simple bone cavity. After 3, 7, 14 and 28 days post surgery 2 objects were sacrificed from each group and histologic specimens were acquired. RT-PCR analysis was conducted and after H&E staining the extent of osseointegration was measured applying a histologic feature and histomorphometric analysis program. Quanitity one -4.41(Bio-Rad, USA) was used after scanning the PCR product image of the growth factors manifested in each group. According to the histomorphometric features the RBM, Machined surface group showed increased contact between bone and implant surface at 3, 7, 14 and 28 days after surgery. The BMP2 level increased in both experiment groups but remained unchanged in the contrast group. BMP4 levels stayed steady after the early post implantation period for RBM but showed decreased in the machined surface group and contrast group. The amount of contact between bone and implant surface increased with the passage of time. BMP2, BMP4 were expressed in both experimental group and contrast group. These growth factors play a role in osseointegration of implant.

• Journal of Korean Neurosurgical Society
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• v.29 no.11
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• pp.1445-1450
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• 2000

Objectives : The Objective of this study was to analyze the prognostic factors affecting survival in the patients with glioblastomas. Methods : We retrospectively studied 55 consecutive patients with glioblastomas who were admitted to neurosurgery department from January 1988 to March 1998. Fifteen pateients were excluded from the analysis because of follow-up loss and surgical motality. There were 24 male and 16 female patients, with a mean age of 51 years. Surgery consisted of biopsy in 4(10.0%) patients, subtotal resection in 9(22.5%) patients and gross total resection in 27(67.5%) patients. Nine(22.5%) patients received second operation. Twenty-eight(70%) received postoperative radiation therapy. Various levels of radiation dose were used, 6,000 rad over 7 weeks in most cases. The variable factors were examined for their relationship with survival ; age at the time of diagnosis, gender, duration of neurological symptoms, preoperative neurological state(Karnofsky performance score), extent of surgical resection, location of tumor, reoperation, and postoperative radiotherapy and chemotherapy. Result : The mean survival time was 55 weeks, three(7.5%) of the 40 patients survived more than two years. Survival time with biopsy only cases was 24 weeks, for those with subtotal resection 43 weeks, and for those with gross total resection 67 weeks. A mean survival time from the time of reoperation was 42 weeks. Statistically significant survival factors in glioblastoma were extent of surgical resection, postoperative radiotherapy and reoperation. Summary : Results of our series support the views that the extent of surgery, reoperation and postoperative radiation are important prognostic factors. We also recommend radical tumor removal, postoperative radiotherapy and reoperation, if possible.

• Journal of Chest Surgery
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• v.20 no.2
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• pp.241-250
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• 1987

We scrutinized the preoperative electrocardiographic and hemodynamic findings in adult atrial septal defects older than 15 years, and then followed up the postoperative electrocardiographic changes sequentially. In preoperative electrocardiographs, the mean PR interval [0.17 sec] was prolonged than normal adults [M;0.13,F;0.15], and the mean QRS axis [93.1*] was deviated to rightward than normal [M;63.7*,F;64.4*], and 122 cases of all 159 patients [77.8%] were in RAD quadrant. The QRS morphology was classified into three groups; a] crista supraventricularis hypertrophy, 25 cases, b] right ventricular outflow tract hypertrophy, 89 cases, c] right ventricular hypertrophy, 44 cases, and normal rs pattern, 1 case. Comparing the QP/QS, Pp/Ps, Rp/Rs in these three groups, Qp/Qs increased a] 2.65 to b] 2.97 and decreased b] 2.97 to c] 2.55, Pp/Ps increased a] 0.27 to b] 0.35 to c] 0.44, and Rp/Rs increased a] 0.1 to b] 0.14 to c] 0.2. In comparing the atrial fibrillation with sinus rhythm, the patient`s mean age was increased [26.4 to 45.7], the mean Qp/Qs was decreased [2.97 to 2.7], the mean Pp/Ps was increased [0.35 to 0.46], the mean Rp/Rs increased [0.14 to 0.2], and the QRS morphology was RVOT hypertrophy;7 cases, RVH;2 cases in all 11 cases. Therefore, the atrial fibrillation was appeared in progressed status. Increasing the mean pulmonary arterial pressure, size of the R` wave in Vl lead increased, and the QRS morphology tended to become severe patterns. Postoperatively, the PR interval shortened and QRS axis tended to normal axis quadrant, and size of R` wave decreased sequentially, atrial fibrillation disappeared in 4 cases. Conclusively, by use of the conventional surface electrocardiography, we could anticipate the hemodynamic changes and the prognosis at outpatient department.

• Korean Journal of Applied Biomechanics
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• v.29 no.2
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• pp.53-60
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• 2019

Objective: The purpose of this study was to investigate the differences of smoothness and coordination of the fingers and upper extremities between skilled and non-skilled players during receiving the basketball. Method: Ten male recreational basketball players (age: $23.2{\pm}2.7yrs.$, career: $8.6{\pm}1.6yrs.$, height: $177.3{\pm}6.0$, weight: $72.9{\pm}8.5kg$) careering over five years and ten non-skilled males (age: $27.3{\pm}1.5yrs.$, height: $173.7{\pm}5.6$, weight: $73.2{\pm}12.6kg$) were participated in this study. Then, participants were asked to perform basketball receiving movement for ten times. The receiving movements were recorded by eight infrared cameras (Oqus 300, Qualisys, Sweden). The collected rad data were calculated to duration of basketball receiving, Jerk-Cost, CRP and CRP variability. Results: The CRP of MCP-Wr, Wr-El in skilled group were greater than non-skilled group (p<.05). The CRP variability of El-Sh in non-skilled group was greater than skilled group (p<.05). Conclusion: These results suggest that skilled players perform more effective movement for impact absorption from the basketball. Moreover, the skilled players have consistent movement patterns during basketball performance. Lastly, it is important to train finger sensation and cognitive ability of thrown basketball from the passer.

• Investigative Magnetic Resonance Imaging
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• v.14 no.1
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• pp.21-30
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• 2010

Purpose : To examine the imaging findings of mucinous breast carcinoma and to evaluate the difference in these findings based on the histopathologic grade. Materials and Methods : We retrospectively analyzed the imaging features according to BI-RADS in 29 patients with surgically proven mucinous carcinoma. The histopathologic grade was classified as well-differentiated, moderately-differentiated and poorly-differentiated. Based on these criteria, the differences in imaging findings were statistically analyzed. Results : Mammography was available in 20 cases, which contained 17 mass lesions (85%) and 3 cases of normal findings. On ultrasonography (27 cases), mucinous carcinoma was observed as a mass with an oval shape (59.3%), a microlobulated margin (55.6%) or an inhomogeneous isoechogenicity (74.1%). On MRI (21 cases), mucinous carcinoma was commonly observed to have a lobular shape (76%), smooth margin (86%) or heterogeneous contrast-enhancement (61.9%). On the kinetic curve, there was a delayed wash-out pattern (52.3%). There were no significant differences in the imaging findings for each histopathologic grade except that a welldifferentiated tumor had an abrupt interface. Conclusion : A well-differentiated mucinous carcinoma tended to have an abrupt interface on ultrasonography, as compared with the moderately-differentiated one. Mucinous carcinoma showed a heterogeneous enhancement and a delayed washout kinetic curve pattern on dynamic MRI.