• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.1
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• pp.74-81
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• 2024

In the near future, autonomous ships, ships controlled by shore remote control centers, and ships operated by navigators will coexist and operate the sea together. In the advent of this situation, a method is required to evaluate the safety of the maritime traffic environment. Therefore, in this study, a plan to evaluate the safety of navigation through ship control simulation was proposed in a maritime environment, where ships directly controlled by navigators and autonomous ships coexisted, using autonomous operation technology. Own ship was designed to have autonomous operational functions by learning the MMG model based on the six-DOF motion with the PPO algorithm, an in-depth reinforcement learning technique. The target ship constructed maritime traffic modeling data based on the maritime traffic data of the sea area to be evaluated and designed autonomous operational functions to be implemented in a simulation space. A numerical model was established by collecting date on tide, wave, current, and wind from the maritime meteorological database. A maritime meteorology model was created based on this and designed to reproduce maritime meteorology on the simulator. Finally, the safety evaluation proposed a system that enabled the risk of collision through vessel traffic flow simulation in ship control simulation while maintaining the existing evaluation method.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.3
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• pp.13-21
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• 2017

This study was carried out to evaluate the application effects of fish meal liquid fertilizer on soil characteristics and growth of cucumber for organic cultivation. Cucumber in greenhouse was transplanted on March $31^{th}$ in 2016, and the experimental treatments involve six treatments: No fertilizer, 0, 25, 50, and 100 mg/L N application by fish meal liquid fertilizer and chemical fertilizer. In the results of soil chemical property, application of 100 mg/L of fish meal liquid fertilizer showed a significant differences in pH, K, and Mg contents. The soil microbial community varied in relation to the fish meal liquid fertilizer treatments. Microbial biomass was lower in the chemical fertilizer than in the liquid fertilizer treatment. Result of principal component analysis obtained from Ecoplate showed that fish meal liquid fertilizer treatments, no liquid fertilizer, chemical fertilizer, and no fertilizer were divided into distinct groups, with the no fertilizer treatment located furthest from the other treatments. There were no significant differences in plant height of cucumber between the fish meal liquid fertilizer treatments and chemical fertilizer treatments. Also, the cucumber yield did not vary significantly between the concentrations of liquid fertilizers, and there were also no significant differences in the yield among the fish meal liquid and chemical fertilizer treatments. In conclusion, it is suggested that the application of fish meal liquid fertilizer can be used as a additional fertilizer for cucumber production with organic culture in greenhouse.

• Korean Journal of Community Nutrition
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• v.1 no.2
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• pp.239-249
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• 1996

Despite the importance of prenatal nutrition, many studies find inadequate calcium intake among pregnant women. The purpose of this study was to investigate the value of the Theory of Planned Behavior in explaining the intentions and the actual consumption of milk among pregnant women participating in or eligible for WIC. A cross-sectional survey was conducted to collect information regarding attitudes, subjective norms, perceived control, milk allocation within the family, intentions and consumption of milk. The survey questionnaire was developed using open-ended questions and interviews with 112 pregnant women. One-hundred-eighty women recruited from prenatal clinics completed the survey questionnaire. Multiple regression was used separately to investigate the association of factors to intentions and to the consu-mption of milk, as proposed in the theory. Milk allocation within the family was used as an exploratory variable to explain milk consumption. Study findings revealed that all three factors, attitudes, subjective norms and perceived control contributed to the model in explaining intentions (explained variance : 36.2%), with perceived control being most important. For milk consumption, intentions and perceived control were related significantly to actual consumption, while milk allocation within the family was not (explained variance : 44.6%). These findings suggest that perceived control is important in understanding both intentions and milk consumption, providing empirical evidence for the Theory of Planned Behavior. With respect to the role of perceived control, more strong evidence was provided in explaining intentions. Findings suggest that educational interventions to increase milk consumption among pregnant women should incorporate strategies to enhance the perception of control, and to strengthen positive attitudes and to elicit social support from significant other. (Korean J Community Nutrition 1(2) 239-249, 1996)

• Korean Journal of Veterinary Research
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• v.41 no.4
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• pp.571-578
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• 2001

To evaluate if the apoptotic fragment assay could be used to estimate the dose prediction after radiation exposure, we examined apoptotic mouse crypt cells per 1,000 cells after whole body $^{60}Co$ $\gamma$-rays and 50MeV ($p{\rightarrow}Be^+$) cyclotron fast neutron irradiation in the range of 0.25 to 1 Gy, respectively. The incidence of apoptotic cell death rose steeply at very low doses up to 1 Gy, and radiation at all doses tigger rapid changes in crypt cells in stem cell region. These data suggest that apoptosis may play an important role in homeostasis of damaged radiosensitive target organ by removing damaged cells. The curve of dose-effect relationship for the data of apoptotic fragments was obtained by the linear-quadratic model $y=0.18+(9.728{\pm}0.887)D+(-4.727{\pm}1.033)D^2$ ($r^2=0.984$) after $\gamma$-rays irradiation, while $y=0.18+(5.125{\pm}0.601)D+(-2.652{\pm}0.7000)D^2$ ($r^2=0.970$) after neutrons in mice. The dose-response curves were linear-quadratic, and a significant dose-response relationship was found between the frequency of apoptotic cell and dose. These data show a trend towards increase of the numbers of apoptotic crypt cells with increasing dose. Both the time course and the radiation dose-response curve for high and low linear energy transfer (LET) radiation modalities were similar. The relative biological effectiveness (RBE) value for crypt cells was 2.072. In addition, there were significant peaks on apoptosis induction at 4 and 6h after irradiation, and the morpholoigcal findings of the irradiated groups were typical apoptotic fragments in crypt cells that were hardly observed in the control group. Thus, apoptosis in crypt cells could be a useful in vivo model for studying radio-protective drug sensitivity or screening test, microdosimetric indicator and radiation-induced target organ injury. Since the apoptotic fragment assay is simple, rapid and reproducible in the range of 0.25 to 1 Gy, it will also be a good tool for evaluating the dose response of radiation-induced organ damage in vivo and provide a potentially valuable biodosimetry for the early dose prediction after accidental exposure.

• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.34-39
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• 2005

Purpose : Perinatal complications associated with maternal smoking and alcohol ingestion in pregnancy have been well documented. But until now there has been no clinical data on it collected in our country. In this paper, we tried to research the association between maternal smoking and alcohol ingestion in pregnancy and the physical indices of the neonate at delivery among unmaried mothers from one charitable institution. Methods : We enlisted 125 unmarried with a history of smoking and alcohol consumption during pregnancy who delivered a baby in National Medical Center from March, 2001 to March, 2004 as a study group. As a control, 174 unmarried mothers without a history of smoking and alcohol were enlisted. Then, we compared the physical indices - birth weight, height, and the head circumference - of the neonates from both groups. Furthermore, we investigated the effects of the period and the quantity of maternal smoking and alcohol ingestion on the physical indices of the neonates from the both groups. Results : Low physical indices of neonates were found in the study group(either smoking group, or drinking group) compared with the control group. The quantity of smoking or drinking and the period of smoking or drinking have no significant effect on physical indices. Conclusion : We found that maternal smoking and alcohol result in the low physical index of neonates, and educational initiatives must be directed at expectant mothers to emphasize the harmful effects of smoking and alcohol ingestion in pregnancy.

• The Journal of Korean Society for Radiation Therapy
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• v.25 no.1
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• pp.25-31
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• 2013

Purpose: The aim of this study is to evaluate the dosimetric properties of robust planning strategy for plain intensity-modulated proton therapy (IMPT) taking into account of the uncertainties of effective proton range and set up error as compared to photon intensity-modulated radiation therapy (photon-IMRT) in prostate cancer treatment. Materials and Methods: The photon-IMRT (7 beams, step & shoot), plain-IMPT (2, 4, and 7 portals), and robust- IMPT plans, which was recalculated the plain-IMPT based on the uncertainties of range error (${\pm}5%$) and set up error (0.5 cm), were evaluated for five prostate cancer patients prescribed by 70 Gy/35 fractions. To quantitatively evaluate the dose distributions, several parameters such as maximum dose, minimum dose, mean dose, conformity index (CI), and homogeneity index (HI) for PTV as well as dose-volume index of VxGy for OARs were calculated from dose-volume histograms. Results: Robust-IMPT showed superior dose distributios in the PTV and OARs as compared to plain-IMPT and photon-IMRT. Like plain-IMPT, robust-IMPT were resulted in dose fluctuation around OARs, while better homogeneity and conformity in PTVs and lower mean dose in OARs as compared to photon-IMRT. Conclusion: In consideration with the effective range correction and set up movement using robustness in IMPT plan, the dosimetric uncertainties from plain-IMPT could substantially reduce and suggest more effective solutions than photon-IMRT in prostate cancer treatment.

• The Journal of Korean Society for Radiation Therapy
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• v.18 no.2
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• pp.113-117
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• 2006

Purpose: Post-mastectomy radiotherapy (PMR) is known to decrease loco-regional recurrence. Adequate skin and dermal dose are achieved by adding bolus. The more difficult clinical issue is determining the necessary number of bolus treatment, given the limits of normal skin tolerance. The aim of this study is to evaluate the necessary number of bolus treatment after PMR in patients with breast cancer. Materials and Methods: Four female breast cancer patients were included in the study. The median age was 53 years(range, $38{\sim}74$), tumor were left sided in 2 patients and right sided in 2patients. All patients were treated with postoperative radiotherapy after MRM. Radiotherapy was delivered to the chest wall (C.W) and supraclavicular lymph nodes (SCL) using 4 MV X-ray. The total dose was 50 Gy, in 2 Gy fractions (with 5 times a week). CT was peformed for treatment planning, treatment planning was peformed using $ADAC-Pinnacles^3$ (Phillips, USA) for all patients without and with bolus. Bolus treatment plans were generated using image tool (0.5 cm of thickness and 6 cm of width). Dose distribution was analyzed and the increased skin dose rate in the build-up region was computed and the skin dose using TLD-100 chips (Harshaw, USA) was measured. Results: No significant difference was found in dose distribution without and with bolus; C.W coverage was $95{\sim}100%$ of the prescribed dose in both. But, there was remarkable difference in the skin dose to the scar. The skin dose to the scar without and with bolus were $100{\sim}105%\;and\;50{\sim}75%$. The increased skin dose rates in the build-up region for Pt. 1, Pt. 2. Pt. 3 and Pt. 4 were 23.3%, 35.6%, 34.9%, and 41.7%. The results of measured skin dose using TLD-100 chips in the cases without and with bolus were 209.3 cGy and 161.1 cGy, 200 cGy and 150.2 cGy, 211.4 cGy and 160.5 cGy, 198.6 cGy and 155.5 cGy for Pt. 1, Pt. 2, Pt. 3, and Pt. 4. Conclusion: It was concludes through this analysis that the adequate number of bolus treatments is 50-60% of the treatment program. Further, clinical trial is needed to evaluate the benefit and toxicity associated with the use of bolus in PMR.

• Journal of agricultural medicine and community health
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• v.24 no.1
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• pp.49-63
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• 1999

The objective of the study was to examine and compare health behavior between rural area and urban area in Soonchun city. Data were collected through personal interviews from 25, April to 30, May in 1998. Questions were asked to the rural area residents(n=399) and urban area residents(n=149) about their health behaviors, including such as self-recognition of health status, health related behaviors(smoking, drinking, eating habit, and exercising), status of disease and prevention, and utilization of hospital. As we examine the demographic characteristics, rural area residents were more aged(p<0.001) than urban area residents. And the urban residents had higher education(p<0.01), higher income(p<0.01) and higher health care cost(p<0.01) than rural residents. There were difference in health status existed between rural and urban residents. Rural residents had poorer health status(p<0.01) than urban residents, and however urban residents had more anxiety about their health(p<0.01) than rural residents. Comparison of the health related behavior between rural and urban area residents, rural residents were more likely to smoke(p<0.05), less intake of milk(p<0.01), do not exercise(p<0.01), and less try to lose their weight(p<0.01) than urban residents. Rural resident used to suffer from chronic diseases than urban residents(p<0.01). Consideration of health care need for rural residents are required due to the results shown as above. Therefore, the health care center, where most of the rural residents depend on for their treatment and prevention of disease, should make inquiries about resident's health care need and evaluate the important information sources for construction of a health care information system.

• Progress in Medical Physics
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• v.16 no.2
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• pp.62-69
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• 2005

The purpose of this study has been performed to investigate the possibility of external audit program using thermoluminescence dosimetry for electron beam in korea. The TLD system consists of LiF powder, type TLD-700 read with a PCL 3 reader. In order to determine a calibration coefficient of the TLD system, the reference dosimeters are irradiated to 2 Gy in a $^{60}CO$ beam at the KFDA The irradiation is performed under reference conditions is water phantom using the IAEA standard holder for TLD of electron beam. The energy correction factor is determined for LiF powder irradiated of dose to water 2 Gy in electron beams of 6, 9, 12, 16 and 20 MeV (Varian CL 2100C). The dose is determined according to the IAEA TRS-398 and by measurement with a PTW Roos type plane-parallel chamber. The TLD for each electron energy are positioned in water at reference depth. In this study, to verify of the accuracy of dose determination by the TLD system are performed through a 'blind' TLD irradiation. The results of blind test are $2.98\%,\;3.39\%\;and\;0.01\%(1\sigma)$ at 9, 16, 20 MeV, respectively. The value generally agrees within the acceptance level of $5\%$ for electron beam. The results of this study prove the possibility of the TLD quality assurance program for electron beams. It has contributed to the improvement of clinical electron dosimetry in radiotherapy centers.

• Journal of Radiation Protection and Research
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• v.23 no.3
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• pp.123-138
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• 1998

Characteristics of element responses of Panasonic UD802 personnel dosimeters in the X, ${\beta}$, ${\gamma}$, ${\gamma}/X$, ${\gamma}/{\beta}$ and ${\gamma}$/neutron mixed fields were assessed. A dose-response algorithm has been developed to decide the high probability of a radiation type and energy by using the distribution in all six ratios of the multi-element TLD. To calculate the 4-element response factors and ratios between the elements of the Panasonic TLDs in the X, $\beta$, and $\gamma$ radiation fields, Panasonic’s UD802 TLDs were irradiated with KINS’s reference irradiation facility. In the photon radiation field, this study confirms that element-3 (E3) and element-4 (E4) of the Panasonic TLDs show energy dependent both in low- and intermediate-energy range, while element-1 (E1) and element-2 (E2) show little energy dependency in the entire whole range. The algorithm, which was developed in this study, was applied to the Panasonic personnel dosimetry system with UD716AGL reader and UD802 TLDs. Performance tests of the algorithm developed was conducted according to the standards and criteria recommended in the ANSI N13.11. The sum of biases and standard deviations was less than 0.232. The values of biases and standard deviations are distributed within a triangle of a lateral value of 0.3 in the ordinate and abscissa, With the above algorithm, Panasonic TLDs satisfactorily perform optimum dose assessment even under an abnormal response of the TLD elements to the energy imparted. This algorithm can be applied to a more rigorous dose assessment by distinguishing an unexpected dose from the planned dose for the most practical purposes, and is useful in conducting an effective personnel dose control program.