• Progress in Medical Physics
• /
• v.13 no.4
• /
• pp.202-208
• /
• 2002

The purpose of this study is to evaluate the monitor unit obtained from various methods for the treatment of superficial cancers using electron beams. Thirty-three breast cancer patients who were treated in our institution with 6, 9, and 12 MeV electron beams, were selected for this study. For each patient, irregularly shaped treatment blocks were drawn on simulation film and constructed. Using the irregular blocks, monitor units to deliver 100 cGy to the dose maximum (dmax) were calculated from measurement and three-dimensional radiation treatment planning (3D RTP) system (PINNACLE 6.0, ADAC Laboratories, Milpitas CA) Measurements were made in solid water phantom with plane parallel (PP) chamber (Roos, OTW Germany) at 100 cm source-to surface distances. CT data was used to investigate the effect of heterogeneity. Monitor units were calculated by overriding CT values with 1 g/㎤ and in the presence of heterogeneity. The monitor unit values obtained by the above methods were compared. The dose, obtained from measurement in solid water phantom was higher than that of RTP values for irregularly shaped blocks. The maximum differences between monitor unit calculated in flat water phantom at gantry zero position were 4% for 6 MeV and 2% for 9 and 12 MeV electrons. When CT data was used at a various gantry angle the agreement between the TPS data with and without density correction was within 3% for all energies. These results indicate that there are no significant difference in terms of monitor unit when density is corrected for the treatment of breast cancer patients with electrons.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.23 no.1
• /
• pp.55-68
• /
• 2007

The purpose of this study was to analyze the distribution of stress in the surrounding bone around implant placed in the first and second molar region. Two different three-dimensional finite element model were designed according to vertical bone level around fixture ($4.0mm{\times}11.5mm$) on the second molar region. A mandibular segment containing two implant-abutments and a two-unit bridge system was molded as a cancellous core surrounded by a 2mm cortical layer. The mesial and distal section planes of the model were not covered by cortical bone and were constrained in all directions at the nodes. Two vertical loads and oblique loads of 200 N were applied at the center of occlusal surface (load A) or at a position of 2mm apart buccally from the center (load B). Von-Mises stresses were analyzed in the supporting bone. The results were as follows; 1. With the vertical load at the center of occlusal surface, the stress pattern on the cortical and cancellous bones around the implant on model 1 and 2 was changed, while the stress pattern on the cancellous bone with oblique load was not. 2. With the vertical load at the center of occlusal surface, the maximum von-Mises stress appeared in the outer distal side of the cortical bone on Model 1 and 2, while the maximum von-Mises stress appeared in the distal and lingual distal side of the cortical bone with oblique load. 3. With the vertical load at a position of 2 mm apart buccally from the center, there was the distribution of stress on the upper portion of the implant-bone interface and the cortical bone except for the cancellous bone, while there was a distribution of stress on the cancellous bones at the apical and lingual sides around the fixture and on the cortical bone with oblique load. 4. With the changes of the supporting bone on the second molar area, the stress pattern on the upper part of the cortical bone between two implants was changed, while the stress pattern on the cancellous bone was not. The results of this study suggest that establishing the optimum occlusal contact considering the direction and position of the load from the standpoint of stress distribution of surrounding bone will be clinically useful.

• International Journal of Aeronautical and Space Sciences
• /
• v.12 no.1
• /
• pp.24-36
• /
• 2011

A new approach for spacecraft absolute attitude estimation based on the unscented Kalman filter (UKF) is extended to relative attitude estimation and navigation. This approach for nonlinear systems has faster convergence than the approach based on the standard extended Kalman filter (EKF) even with inaccurate initial conditions in attitude estimation and navigation problems. The filter formulation employs measurements obtained from a vision sensor to provide multiple line(-) of(-) sight vectors from the spacecraft to another spacecraft. The line-of-sight measurements are coupled with gyro measurements and dynamic models in an UKF to determine relative attitude, position and gyro biases. A vector of generalized Rodrigues parameters is used to represent the local error-quaternion between two spacecraft. A multiplicative quaternion-error approach is derived from the local error-quaternion, which guarantees the maintenance of quaternion unit constraint in the filter. The scenario for bounded relative motion is selected to verify this extended application of the UKF. Simulation results show that the UKF is more robust than the EKF under realistic initial attitude and navigation error conditions.

• The Journal of Korean Society for Radiation Therapy
• /
• v.10 no.1
• /
• pp.30-44
• /
• 1998

Accurate delivery of doses using a high dose rate(HDR) brachytherapy, remote afterloading system(RALS) depends on knowing the strength of the radioactive source at the time of treatment, the precision and consistency of the timer, and the ability of the unit to position the source at the proper dwell location along the applicator. Periodic Quality Assurance(QA) on HDR machines is a part of the standard protocol of any user. The safety of the patient & staff, positional accuracy, temporal accuracy, and dose delivery accuracy are periodically(weekly, quarterly, monthly) estimated using HDR source(Ir-192), treatment planning devices, measurement devices, and overall treatment devices with regard to treatment delivery. The overall measurement results are estimated successfully and assessed its clinical significance. As a result, our HDR brachytherapy units has been very accurate until now. The QA program protocol permits routine clinical use and provides a high confidence level in the accurate operation of HDR units. Therefore, regular QA of HDR brachytherapy is essential for successful treatment.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.20 no.7
• /
• pp.25-32
• /
• 2021

In the previous study, a study was conducted to improve the exhaust gas intake efficiency by improving the existing soot measurement probe in the shape and angle of the exhaust port. As a result, it can be seen that the smoke measurement performance according to the shape and angle is improved. In previous studies, the performance of the soot probe was not confirmed for the Korean KD 147 mode, which has a low suction flow rate and a long inspection time. So, we would like to confirm the improvement of the smoke probe performance of the Korean KD 147 mode, which is close to the actual driving conditions. The probe used in this study is another type of probe, and has a circular ring shape instead of a rib and variable center position unit, so the probe center hole is located close to the center of the exhaust pipe.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.spc8
• /
• pp.3045-3050
• /
• 2011

The synthesis of copolymers containing thiophene and benzimidazole unit by Stille polymerization is reported. The polymers with many unsubstituted thiophene units in the backbone have been reported to show low solubility, which has been a problem for spin-coating for the device fabrication. In dihexyl-2H-benzimidazole, the sulfur at 2-position of BT unit was replaced with dialkyl substituted carbon, while keeping the 1,2-quinoid form, to improve the solubility of the polymers. The PL emission spectra of the PHBIT1, PHBIT2 and PHBIT3 in chloroform solutions show maximum peaks at 500~561 nm. In thin films, maximum peaks of the PHBITs appeared at 529, 562 and 569 nm, respectively. The EL emission maxima of the PHBIT1 and PHBIT2 appear at around 588 and 576 nm, respectively. The current density and maximum luminescence of the LED with the configuration of ITO/PEDOT/ PHBIT2/Ca/Al are 552 mA/$cm^2$ and 46 cd/$m^2$, respectively.

• ETRI Journal
• /
• v.38 no.3
• /
• pp.417-424
• /
• 2016

In this paper, an accurate characterization of a fabricated X-band transmit/receive module is described with the process of generating control data to correct amplitude and phase deviations in an active electronically scanned array antenna unit. In the characterization, quantization errors (from both a digitally controlled attenuator and a phase shifter) are considered using not theoretical values (due to discrete sets of amplitude and phase states) but measured values (of which implementation errors are a part). By using the presented procedure for the characterization, each initial control bit of both the attenuator and the phase shifter is closest to the required value for each array element position. In addition, each compensated control bit for the parasitic cross effect between amplitude and phase control is decided using the same procedure. Reduction of the peak sidelobe level of an array antenna is presented as an example to validate the proposed procedure.

• Journal of Korean Academy of Nursing Administration
• /
• v.6 no.1
• /
• pp.55-81
• /
• 2000

This study examined nursing care in a Newborn Intensive Care Unit (NICU) by reviewing nursing activities for the newborns. Through direct observation, time used for nursing care according to the nursing activity, shift, day of the week, and position of the nurses was measured. This study was done on November 15, 21, 24, 1999 at a university medical center hospital and included eight nurses and 179 newborns as the study subjects. The data were collected from the medical records, and by using a nursing activity record for the NICU, and a nursing activity time record for the NICU. The first step in the data collection process was to develop a list of nursing activities which was done through a literature review, examination of medical affairs and duty records. Content validity was measured by a panel of three professors who were experienced clinicians. In the second step two pre-training sessions were held with three sophomore student nurses who then measured the time for each nursing activity using a stopwatch. The data were analyzed using frequencies for nursing activities, averages, percentages and ANOVA for differences between shift and between days of the week, and percentages and t-test for differences according to position of the nurse. The results are as follows: 1) The total number of activities was 156, direct or indirect nursing activities. Direct nursing activity classified according to physical, educational, emotional/social/economic/spiritual needs. There were 109 direct nursing activities in 16 fields. 2) The order of nursing activities, according to time required, was record keeping, nutritional care, measurement/observation, medication, hygiene care, examination and specimen collection, and checking supplies, and according to frequency, measurement/ examination, record keeping, nutrition care, hygiene care, elimination care and medication. 3) According to shift, direct care during the night shift at 313.4 minutes was the longest time and indirect nursing care during the night shift at 252.2 minutes was the highest time. 4) For days of the week, Monday had the highest time for direct care 275.8 minutes (34.6%) and Wednessday had the highest time for indirect nursing care 269.6 minutes (36.1%). 5) For nursing time according to position of nurse, general nurses had the highest for direct care (330.7 minutes), nurse managers for indirect nursing activities (239.0 minutes) and general nurses for individual private time (63.9 minutes). The results of this study show that the major nursing time consuming activities included record keeping, nutrition care and measurement/examination. For newborns, time needs to be allowed for care to be sensitive, sophisticated and specialized rather than concentrated on indirect nursing tasks such as record keeping. Therefore, it is imperative to develop computerized systems that support a systematic approach to record keeping which is more efficient. Moreover, nursing needs according to shift, day or position of nurse can be utilized in assessing nursing resources through a computerized process.

• Journal of Fisheries and Marine Sciences Education
• /
• v.23 no.4
• /
• pp.723-733
• /
• 2011

On the general fishing boat in the same person of the fishing Chief and the Captain, the fishing chief positions are not separately. In this case, in Civil, Criminal and Administrative law, does not cause any problems. Just he take only responsibility for the legal effect of each, this is a natural solution for the effects of laws. But, if make one work unit, the fishing chief take fishing work from the position of the dominant of the captain, and moreover throughout the voyage work commands the captain. Such fishing chief center structure have roots institutive. In the case, according to legal liability by presenting solutions to the problem are as follows : firstly, The legal division Of the Sailing courses and operation course are necessary. Secondly, In the adminstrative ship official law, obligatory acquisition of the fishing Chief marine engineer qualification is necessary.

• Journal of Institute of Control, Robotics and Systems
• /
• v.17 no.1
• /
• pp.1-5
• /
• 2011

The basic signals for electronic engine control are velocity and degree of the engine cam shaft. The CPS sensor used for this signal and magnetic pick-up type CPS sensor is more popular. It is very important thing analyze this signal correctly. If there are some mistakes at the analysis, like a noise, The engine do not working at the best status, it will generate some noise, emit exhaust fumes and waste more gases. In general way to analysis this signal, you use zero-level detector circuit and in order to reduce the error you must use another sensor like a TDC sensor. In this paper, We proposed the analysis method using electronics circuits for magnetic pick-up type CPS sensor. We designed Comparison level detector circuit, Differential circuit and Full-rectifier circuit for detected the Long tooth and Short tooth level correctly without another sensor. We expected it is useful for more reliable engine control.