• 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.

• Hwankyungkyoyuk
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• v.3 no.1
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• pp.130-140
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• 1992

The purpose of this study was to survey the trends of waste products in schools, its gathering and disposal, identification of problems and to analyze its disposal. Moreover, this study was aimed at basic suggestions about the establishment and plans of waste environmental education. 98 public primary and secondary schools were surveyed in Seoul during the month of March and April, 1991. Information was collected from each educational association by random sampling. Questionaries were used for this survey. To understand the disposal status of school waste and its reforms, this study surveyed the amount of waste by products, their origin and analyzed the disposal by type, one number of schools and teachers involved. The dump sited and disposal methods of school waste, its problems, and the status of school waste educations were researched, and ideal disposal methods and plans for waste education were suggested. The results were as follows. 1. The School's trash was produced by followings: paper, vinyle plastics, food, woods, metals, ceramics, glass, bottles, and ash from the heating system. The biggest cause of the school's waste as shown by the survey was a lack of environmental awareness(39.8%). The second biggest was the use of a one time use of disposable paper products(27.6%). 2. Waste collection by different grade levels were proven to be important but as you move from elementary to high school, the waste collecting operation decreased, in this connection between the students and waste collection itself it was significant on the other hand the teachers were not working as significant variables. 3. Of the school that collected waste 69.5 percent of the schools separately grouped common waste and recyclable waste. 25 schools(42.4%) received improvement on their environmental awareness of trash collection through this method. 4. From the number of disposal sites in surveyed schools, it was determined that the education of the necessity for separation of waste was performed in vain and accordingly the should require a real education in the future. 5. Regarding the method of disposal of waste the survey indicated that the #1 method of disposal was partial burning and the remains carried to a dump site by others(35,7%). In elementary schools the entire waste was taken by individuals to a dump site (33.3%). In high schools partial burning and then transported by individuals #1 in our survey(50%). 6. Relative to the problem of the treatment to waste, the emission of smoke from the burning was considered to be the #1 priority in our survey (62.3%) the problem of trash collection being delayed was 52.1%(1in our survey). 7. The present situation of environmental education of waste us lacking. Under present circumstances, the practice of public announcements for improvement and waste-paper collection has been going on vigorously but lacking in education as to the preparation of compositions for students the themes of public exhibitions, the organizing of voluntary associations should be part of the education system to reinforce student's awareness of proper waste disposal. 8. The most economical alternative for disposal was recycling usable waste or combustible material through a variety of education we can therefore educate students bring this education to their homes public servants will also be able to benefit in the waste disposal process with proper education. In conclusion we should intensify the systemical organization and the education of our waste disposal for a better environment.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.93-100
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• 2012

Objective: This study is to review the current state of services offered to pharmacy users, and develop a service design converging a prescription service and a smart phone application service in order to enhance patients' experience at pharmacies and home. Background: Under the new medical system; separation of prescribing and dispensing drugs, a doctor writes a prescription to their patients and patients have their prescription filled at the pharmacy. As the number of flue, allergy and atopy patients has increased, waiting lines have been longer at pharmacies. Besides, the current medical service system lacks of providing proper information on prescribed pills to patients. There are already services offered during waiting times such as offering free drinks, magazines or suggesting general drugs which you can buy without prescription, however they neither cover the current medical service's shorts nor shorten the waiting time. Method: I researched objective and perceived waiting times reduction methods, the current service status at pharmacies, and the government's policy direction in a medical service. Also, I observed a patient's journey from the hospital to pharmacy and then home. I examined the circumstance at pharmacies, patients' behaviors and their thoughts during their journey, and extracted three main goals to design a service in order to help patients have positive perception during the waiting time; (1) to reduce the perceived time by the way of visualizing time and offering readings about what patients consider necessary, (2) to educate patients what they are into and how to get through, (3) to establish trust among patients, doctors and pharmacists. Based on three goals, I designed a structure and a wireframe for a new service application of smart phones. Results: With a new service design for pharmacy users, users can track their medical record and visit the information about their current medical treatments anytime. Also the service helps patients build reliable relationships with doctors and pharmacists. Conclusion: Experience is not just an activity but series of multiple activities. The serving range of a medical service should not be determined by stakeholders but user's holistic experience. By approaching a service design with a holistic vision, it can enrich not only a temporary experience but also a whole life well being. Application: Since there are already many service applications advising patients about their illness and finding right doctors, this service design is focused on the experience from getting a prescription till feeling better. The next move is to combine those two parts medical services and design an integrated service application. As a prescription is going to be coded in numbers, we might consider to design an un-attended pharmacy which can shorten huge amount of time for filling prescriptions.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.11
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• pp.1-10
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• 2007

In this paper, we proposed channel estimation scheme for LR-UWB system which has low data rate for WPAN in IEEE 802.15.4a. At the transmitter, we proposed dynamic power level allocation depends on channel condition in specific period when we modulate signal. We use two orthogonal code to estimate channel at once. It can estimate channel more accurately by using two code which shows good correlation characteristic then it can estimate more accurately by spreading gain. Using estimated channel condition, we synchronize symbol timing of transmitted signal. Then determined power allocation scheme and channel information is transmitted to transmiter side. Finally, using these information, transmiter side change the power level of repeated pulse to adopt to channel condition. Simulation is performed under S-V channel for LR-WPAN in IEEE 802.15.4a and we compare the performance with a different type of receiver type. We use coherent and non-coherent method at the receiver. Simulation result shows us at the NLOS channal performance evaluation is greater than that of LOS channel and the result is independent of receiver type. In the NLOS channel, as the signal delay spreading is big, performance evaluation is also increased.

• Journal of Life Science
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• v.25 no.10
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• pp.1103-1109
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• 2015

Cholinergic innervation of the hippocampus is known to be correlated with learning and memory. The cholinergic agonist carbachol (CCh) modulate synaptic plasticity and produced long-term synaptic depression (LTD) in the hippocampus. However, the exact mechanisms by which the cholinergic system modifies synaptic functions in the hippocampus have yet to be determined. This study introduces an acetylcholine receptor-mediated LTD that requires internalization of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptors on the postsynaptic surface and their intracellular mechanism in the hippocampus. In the present study, we showed that the application of the cholinergic agonist CCh reduced the surface expression of GluA2 on synapses and that this reduction was prevented by the M1 muscarinic acetylcholine receptor antagonist pirenzepine in primary hippocampal neurons. The interaction between GluA2 and the glutamate receptor-interacting protein 1 (GRIP1) was disrupted in a hippocampal slice from a rat upon CCh simulation. Under the same conditions, the binding of GluA2 to adaptin-α, a protein involved in clathrin-mediated endocytosis, was enhanced. The current data suggest that the activation of LTD, mediated by the acetylcholine receptor, requires the internalization of the GluA2 subunits of AMPA receptors and that this may be controlled by the disruption of GRIP1 in the PDZ ligand domain of GluA2. Therefore, we can hypothesize that one mechanism underlying the LTD mediated by the M1 mAChR is the internalization of the GluA2 AMPAR subunits from the plasma membrane in the hippocampal cholinergic system.

• Journal of the Korean Home Economics Association
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• v.41 no.10 s.188
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• pp.101-116
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• 2003

The study was conducted to establish hygienic standards of salad items for pizza restaurant located in Seoul by applying HACCP system during the summer of 2000. The study measured temperature, time, pH, Aw and microbial assessments. The hygienic conditions of the kitchen and workers were on the average(1.21, 1.0 out of 3 pts.), but some improvement should be made: separate use of trash can and leftover disposal, separate use of knives and cutting boards, habits for hand washing and wearing hygienic gloves. For salad production, all procedures were peformed under food safety danger zone ($5{\~}60^{\circ}C$). The ingredients were mostly above pH 5.0 and high in Aw($0.94{\~}0.99$). Microbial assessments for salad production revealed that TPC($1.8{\times}10^3{\~}1.0{\times}10^{10}CFU/g$) and coliforms($1.5{\times}10{\~}5.2{\times}10^5 CFU/g$) exceeded the standards by Solberg et al.(TPC: $10^6CFU/g$, coliforms: $10^3CFU/g$). S. aureus was not detected but Salmonella was found in three food items(egg, macaroni and macaroni salad). Moreover, the workers' hands contained 3.1 104 CFU/g of TPC and 4.2 102 CFU/g of S. aureus requiring further remedy since it exceeded the safety standards suggested by Harrigan and McCance (500 CFU/g of TPC per $100cm^2$ and 10 CFU/g of coliforms per $100cm^2$). According to the critical control point(CCP) decision tree analysis, vegetable receiving, vegetable holding, mixing, display on coleslaw, macaroni draining, display on macaroni salad, egg peeling & cutting, apple cutting, and display on salad bar were determined as CCPs. From the findings it would be suggested that purchase of Quality materials, short holding and display time, storing food at right temperature, using sanitary cooking utensils, and improvement of workers' food handing practices are needed to ensure the safe salad production in this specific pizza restaurant.

• Korean Journal of Poultry Science
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• v.28 no.3
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• pp.215-224
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• 2001

Since nitrogen(N) is a volatile compound affected by many environmental factors, determining the N content of manure tends to be difficult. Upon arrival in the laboratory, the manure should be moist and refrigerated. Manure samples will have variable N contents due to drying temperature, and the presence of soil in the sample will affect N content. Acidification of the sample prevents ammonia volatilization and should be done before drying. It is recommended that manure samples be pretreated with a strong oxidizing agent, KMnO$_4$, followed by digestion under reduced conditions (reduced Fe-$H_{2}$ $SO_{4}$ ), which achieves a complete recovery of both $NO_{3}$ -N and $NO_{2}$ -N without a low recovery of $NH_{4}$ -N, resulting in a more accurate determination of N content. Accuracy of results for N content determined by recently developed rapid analysis techniques in the field should be tested by comparison with results obtained at laboratories using approved standard methods. Most commonly, the Kjeldahl system is used to determine manure N content. More research is needed on the effects of species, breed, age and individuals on the nutrient contents of manure. The procedures for manure sampling on the farm, shipping and handling of the sample until it reaches the laboratory, and the methods of sampling of the manure at the laboratory must be studied. Development of animal agricultural laboratories where feed, manure, soil, and water are all analyzed by appropriate specialists is needed.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.2
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• pp.191-204
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• 2005

Building and furnishing materials and consumer product are important sources of volatile organic compounds(VOCs) and other aldehydes in the indoor environment. Some available evidence indicates that VOCs can cause adverse health effects to the building occupants and contribute to some of the symptoms of what we call, 'Sick House Syndrome' in Korea. The aims of this study were to evaluate the efficiency of emission system and to investigate comparison of the emission characteristics of different building materials such as wall-papers, paints, and adhesives. The emission of VOCs from building materials were determined in the small chambers defining the temperature, relative humidity, and ventilation rate in this study. VOCs were sampled for 20 minutes using Tenax-TA tubes and analysed by GC-MS with thermal desorption. The stability of conditions for temperature and relative humidity in this small chamber system showed that the fluctuation of temperature was between 25.4$\pm$0.3$^{\circ}C$ and that of relative humidity was 50.2$\pm$0.6$\%$ under the airflow rate of 167 mL/min. The emission tests from building materials resulted in TVOC emission rates of 0.011 $\~$ 3.108 mg/m$^{2}$h after 7 days. The general wall-papers emitted toluene abundantly and the natural wall-papers mainly emitted n-butanol and a minor amount of alkanes compound such as n -tetradecane. The remainder consisted of toluene, m,p -xylene, and styrene. The paints mainly emitted toluene and the adhesives mainly emitted chloroform as well as toluene. As a result, this study is expected to suggest meaningful data for future studies in exposure control through selecting healthy building materials and for the establishment of guidelines for various building materials in Korea.

• Journal of Chest Surgery
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• v.21 no.3
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• pp.425-446
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• 1988

After 24 hours of preservation under 15 mmHg perfusion pressure the recovery rates of isolated canine hearts were determined. Preservation was performed in a cold room maintained at 4*C with 4 different types of perfusates bubbled with a mixture of 95% 0y and 5% CO~ using a modified perfusion unit designed in our institute. The perfusates used were as follows; Group 1: Krebs-Henseleit solution, Group 2: Krebs solution added by albumin and PGE1. Group 3: Modified Wicomb*s solution, Group 4: Modified Collin*s solution. The extent of myocardial recovery was evaluated using a modified isolated carmine perfusion model by measuring heart rate, systolic arterial pressure, left atrial pressure[LAP] and cardiac output. In addition to the above hemodynamic parameters, biochemical and enzymatic assays from perfusates and electron microscopic changes of the myocardium were also studied. The results were as follows; 1] The heart recovery rates were 41.6%, 53.4% and 108.9% in groups 1, 2 and 3, respectively, and group 3 elicited the best result[p< 0.001]. The heart beat was never recovered in group 4. 2] Recovered systolic arterial pressures[mmHg] were 63.3% in group 1, 94.9% in group 2 and 94.3% in group 3. 3] LAPs[mmHg] were 20 in group 1, 13.5 in group 2 and 11.2 in group 3, which suggested that the best myocardial preservation was elicited in group 3[p< 0.05]. 4] Cardiac output, the sum of aortic stroke volume and coronary leakage, were 69.1% in group 2, and 90.7% in group 3, but these were not statistically significant[p=0.24]. No aortic stroke output was measured in group 1 and 4. 5] The degree of myocardial edema increase was 17.5` in group 1, 24.6% in group 2, 20.9% in group 3 and 55.3% in group 4. But there were no statistical differences in each group[p= 0.08]. 6] CPK-MB[U/L] levels were increased 750% and 332%[p< 0.05], glucose levels[mg/dl] 60.5% and 78.2% and SGOT[U/L] levels 523% and 333%, in groups 2 and 3, respectively. Biochemical and enzymatic assays could not be performed in group 1 and group 4, because of poor recovery of heart beat. 7] Electron microscopic findings in the myocardium of most groups revealed slight to moderate muscle cell and mitochondrial edema. But all these findings were within the limits of reversible change. From these above results, it is suggested that modified Wicomb*s solution seems to be the most useful physiologic salt solution for preservation of the heart. We propose that after further study and improvement, our portable continuous hypothermic perfusion system will contribute to the development of a better preservation method for donor hearts for human heart transplantation.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.1
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• pp.22-28
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• 2015

The design on a riser in 1MW OTEC system is performed. The minimum diameter of the riser is decided depending on intake quantity of deep-sea water to supply an OTEC cycle. An applicable pipe material is selected from analyzing the properties of commercial pipes. The selected HDPE pipe with the low density and strength is reinforced with a lumped block attached at the end of and wire ropes along the riser. A lumped block, connected to a floating structure by wire ropes, with 25% and 50% weight of a GFRP riser is designed to be attached the end of a riser. The structural safety of the HDPE riser with wire rope supporting axial loads induced by a lumped block is analyzed under the harsh ocean environmental condition near Hawaii ocean with the numerical method. The final dimension of the riser and accessories is determined considering the economic point of view. The designed riser will be applicable to the construction of the 1 MW OTEC pilot plant.