• Membrane Journal
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• v.32 no.4
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• pp.235-252
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• 2022

Forward osmotic pressure-free reverse osmosis (Δ𝜋=0 RO) was invented in 2013. The first patent (US 9,950,297 B2) was registered on April 18, 2018. The "Osmotic Pressure of Concentrated Solutions" in JACS (1908) by G.N. Lewis of MIT was used for the estimation. The Chang's RO system differs from conventional RO (C-RO) in that two-chamber system of osmotic pressure equalizer and a low-pressure RO system while C-RO is based on a single chamber. Chang claimed that all aqueous solutions, including salt water, regardless of its osmotic pressure can be separated into water and salt. The second patent (US 10.953.367B2, March 23, 2021) showed that a low-pressure reverse osmosis is possible for 3.0% input at Δ𝜋 of 10 to 12 bar. Singularity ZERO reverse osmosis from his third patent (Korea patent 10-22322755, US-PCT/KR202003595) for a 3.0% NaCl input, 50% more water recovery, use of 1/3 RO membrane area, and 1/5th of theoretical energy. These numbers come from Chang's laboratory experiments and theoretical analysis. Relative residence time (RRT) of feed and OE chambers makes Δ𝜋 to zero or negative by recycling enriched feed flow. The construction cost by S-ZERO was estimated to be around 50~60% of the current RO system.

• Fire Science and Engineering
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• v.34 no.2
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• pp.156-165
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• 2020

In this paper, the application of evacuation delay time (Cognition time + initiation time) and examine the degree of opening of fire doors in households for evaluating evacuation safety and suggest a realistic alternative. In order to proceed with this study, first of all, the preliminary investigation on evacuation safety evacuation of residential-type buildings (Apartment, urban living houses, etc.) among the performance-oriented design targets of Gwangju Metropolitan City, which was implemented until June 2018. Then, for the two representative types that are commonly used among the previously surveyed buildings, evacuation delay time is applied to W1, W2, and respectively simulating the opening of the doors is applied to th full open, 1/4 open, the leakage gap and evacuation safety evaluation was performed. As a result of evaluating evacuation safety was found that it is difficult to secure evacuation safety regardless of evacuation delay time W1 and W2 when the fire door is fully open and 1/4 open, Only when the leakage gap is applied evacuation safety was ensured even if evacuation delay time W2 was applied. Therefore, when a residential building is subject to performance-oriented design, evaluating the application of W2 rather than W1 is considered for evacuation delay time to reflect concern about privacy infringement due to CCTV installation, etc. In order to secure the Smoke blocking performance of the fire door and to improve the performance-oriented design, I would like to propose to consider the method of applying a leak gap to the degree of opening of the fire door. Through this, it is expected that the performance-oriented design will be a step further by performing evacuation safety evaluation with more realistic data.

• Tuberculosis and Respiratory Diseases
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• v.44 no.2
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• pp.241-250
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• 1997

Objective : Although the prevalence of pulmonary tuberculosis has decreased progressively after the national control program for tuberculosis began, nowadays the number of MDRTB is increasing seriously. MDRTB tends to be poor responsive to current antituberculosis regimens. It is mainly due to poor compliance, high rate of side reaction of secondary drugs, and limitation in number of available drugs. The purpose of present study is to evaluate the clinical features of pulmonary tuberculosis patients admitted in one national tuberculosis hospital and to expose the problems pertaining to current remedies, to increase the treatment efficacy for pulmonary tuberculosis including MDRTB in the end. Method : Retrospective analysis of 336 pulmonary tuberculosis patients admitted in National Masan Tuberculosis Hospital was done. Contents of analysis were patients profile, the first diagnosed time and medical institutes, family history, residence, previous treatment history, chief complaints at the time of admission, lesion site on chest X -ray film, combined deseases, side reaction to antibuberculosis drugs, used drugs before admission and the results of drug sensitivity test. Results : The ratio between male and female was 4 : 1. Age showed relatively even distribution from 3rd to 6 th decades. 64.6% of the patients was diagnosed at public health center. Weight loss was the most common complaint at admission. Bilateral lesions on chest X-ray films were 59.8%. 130patients had combined desease, of which DM was the most common(37.7%). 95patients had family history, of which parents were the most common(41.7%). According to the time of first diagnosis, 31 patients were diagnosed before 1980, and after then the number of patients was increased by degrees. Residence overwhelmed in pusan and gyung-nam province. 258 patients got previous treatment history, of which 112 patients(43.4%) had more than 3 times and only 133 patients(51.6%)got regular medication. 97 patients used more than other 3 drugs in addition to INH, EMB, RFP and PZA before admission. 154 patients were informed with the results of drug sensitivity test. of which 77 patients had resistance to more than 5 drugs. Gastrointestinal problem was the most common in side reaction to drugs. Conclusion : In the case of weight loss of unknown cause, tuberculosis should be suspected. In first treatment, sufficient and satisfactory explanation for tuberculosis is necessary and treatment period should not be stict to 6 month-short term therapy. In retreatment, new drugs should not be added to used drugs even though drug sensitivity results show sensitivity to some of them. Proper time for surgical intervention should not be delayed.

• Korea Journal of Hospital Management
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• v.6 no.2
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• pp.70-85
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• 2001

This study has been conducted, on the reservation of specific examinations during seven months starting from June 1999 and ending December as the Group I for these of one stop service and as the Group II for those of existing direct reservation made by patients or patrons, to understand the differences between the two groups. The survey was extended to the patients visiting specific departments of K hospital with sample sizes of 154 for the Group I and 155 for the Group II. The findings of the survey are as follows: First, as the general characteristics of the sample, male patients account for 67% of the total and female patients 33%, with the former twice as large as the latter. The average age of the patients is 51, indicating relatively high level. By the geographical area of residence, metropolitan area is 80.7% and the other area 19.3%, showing most of the patients are from metropolitan area. The general characteristics do not have statistical significance between the Group I and the Group II(p>0.05). Second, regarding the ratio by the number of examinations, the Group I shows 37.0% for one examination and 63.0% for two examinations, while the Group IT indicates 30.3% for one examination and 69.7% for two examinations. The populations by the number of examinations do not have statistical difference between the two Groups(p>0.05). Third, regarding the time required for the reservation of examinations by the number of examinations, the Group I shows 9.8 minutes for one examination and 19.8 minutes for two examinations, with the average of 16.1 minutes. The Group IT indicates 19 minutes for one examinations and 25.7 minutes for two examinations, with the average of 23.7 minutes. Though the time required for the reservation by the number of examinations do not have statistical significance, the time required for the Group I was shortened. Fourth, regarding the time required for the reservation of examinations by the age range of patients, the Group I shows 21.7 minutes for 70-79 years of age, 17.5 minutes for 60-00 years of age, and 15.2 minutes for 30-39 years of age. The Group II indicates 27.2 minutes for 70-79 years of age, 26.3 minutes for 60-69 years of age, 24.4 minutes for 50-59 years of age, and 22.4 minutes for 30-39 years of age. The time required for the reservation gets longer as the age range moves up, and has statistical significance (p<0.05). Fifth, regarding the ratio by the range of time of required for reservation, the Group I shows 41.6% for 11-20 minutes, and 38.3% for 1-10 minutes, while the Group II indicates 43.9% for 11-20 minutes, 29% for 21-30 minutes, and 14.2% for 31-40 minutes. Statistical significance is revealed (p=0.001). Sixth, concerning the length of movement course by the number of examinations, the Group I shows 37 meters regardless of the number of examinations. The Group II indicates an average of 188 meters for one examination and 189 meters for two examinations, with the difference 151 meters between the Groups, and representing statistical significance (p=0.001). Based on the above findings. one-stop service contributes to the reduction of both the time and the movement course and therefore is considered to be beneficial to the patients, and the improve the efficiency of the hospitals in terms of the space and the time.

• 한국해양학회지
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• v.30 no.4
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• pp.279-287
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• 1995

The vertical profiles of natural ²¹⁰Pb, ²¹⁰Po and ²³⁴Th activities were measured for the upper 100 m of water column at three stations in the middle region of the Korean East Sea during May 1992. And the distribution of these radionuclides was discussed associated with the formation of warm eddy or water mass. The main thermocline was maintained between the depth of 50 and 100 m at the southern station (Sta. A1), and between the depth of 10 to 50 m at the coastal station of Sockcho (Sta. B10). Contrastingly, a main thermocline at Sta. A10, which locates near the center of warm eddy, was observed below 230 m depth. Between 50 and 220 m depth of Sta. A10 is there a relatively homogeneous water mass of 10.1${\pm}$0.5$^{\circ}C$, which is significantly higher in temperature and lower in nutrient than the other two stations. It seems to be due to sinking of the warm surface water in which nutrients were completely consumed. Both ²¹⁰Pb and ²¹⁰Po show the highest concentration at Sta. A1 and the lowest at Sta. B10 among the three stations. Also, the ²¹⁰Pb activity is generally higher in the upper layer than in the lower layer, while ²¹⁰Po activity represents the reversed pattern at all three stations. At Sta. A1 and Sta. B10, the activities of ²¹⁰Po relative to its parent ²¹⁰Pb were deficient in the water column above the main thermocline, but were excess below the thermocline. However, the station near the center of warm eddy(Sta. A10), shows no excess of ²¹⁰Po in the depths below 50 m, although its defficiency is found in the upper layer like the other stations. At Sta. A1 and b10. ²³⁴Th activities are slightly lower in the surface mixed layer than in the deeper region However, at Sta. A10, ²³⁴Th activity in the upper 30 m is higher than below 50 m or in the same depth of the other stations, probably because of the high concentration of particulate matter. The residence time of ²¹⁰Po in the surface mixed layer at Sta. A10 is 0.4 year, much shorter than at the other two stations(about one year). Above 100 m depth, the residence times of ²³⁴Th range from 18 to 30 other two stations(about on year). Above 100 m depth, the residence times of ²³⁴Th range from 18 to 30 days at all stations, without significant regional variation. The percentages of recycled ²¹⁰Po within the thermocline are 39% and 92% at Sta. A1 and Sta. B10, respectively. Much higher value at Sta. B10 may be due to a thin thickness of the mixed layer as well as the slower recycling rate of ²¹⁰Po in the main thermocline.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.40 no.2
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• pp.1-13
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• 2022

This paper examined the history and development of Gyeongbokgung Palace's back garden based on historical materials and drawings such as Joseon Ilgi(Diaries of Joseon Dynasty), Joseon Wangjo Sillok(the Annals of the Joseon Dynasty), Doseongdaejido(the Great Map of Seoul), Bukgwoldohyeong(Drawing Plan of the Northern Palace), the Bukgung Palace Restoration Plan, Restoration Planning of Gyeongbokgung Palace and the following results were derived. First, it was confirmed that the Back Garden of Gyeongbokgung Palace was famous for its great location since the Goryeo Dynasty, and that it was named Namkyeong at that time and was a place where a shrine was built, and that castles and palaces were already built during the Goryeo Dynasty under the influence of Fengshui-Docham(風水圖讖) and Zhouli·Kaogongji(周禮考工記). Although the back garden of Gyeongbokgung Palace in the early Joseon Dynasty stayed out of the limelight as a back garden for the palace, it has a place value as a living space for the head of the state from King Gojong to the present. Second, in order to clearly identify the boundaries of back garden, through literature such as map of Doseongdo (Map of the Capital), La Coree, Gyeongmudae Area, Japanese Geography Custom Compendium, Korean Photo Album, JoseonGeonchukdoJip(The Illustration Book of Joseon Construction), Urban Planning Survey of Gyeongseong, it was confirmed that the current Blue House area outside Sinmumun Gate was built outside the precincts of Gyeongbokgung Palace. It was found that the area devastated through the Japanese Invasion of Korea in 1592, was used as a space where public corporations were combined through the process of reconstruction during the King Gojong period. In Japanese colonial era, the place value as a back garden of the primary palace was damaged, as the palace buildings of the back garden was relocated or destroyed, but after liberation, it was used as the presidential residence and restored the place value of the ruler. Third, in the back garden of Gyeongbokgung Palace, spatial changes proceeded through the Japanese Invasion and Japanese colonial era. The place with the greatest geographical change was Gyeongnongjae area, where the residence of the Japanese Government-General of Korea was built, and there were frequent changes in the use of the land. On the other hand, the current Gyeongmudae area, the forests next to the small garden, and the forests of Baekak were preserved in the form of traditional forests. To clarify this, 1:1200 floor plan of inner Gyeongmudae residence and satellite images were overlapped based on Sinmumun Gate, and as a result, it was confirmed that the water path originating from Baekak still exists today and the forest area did not change. Fourth, in the areas where the traditional forest landscape was inherited, the functional changes in the topography were little, and major old-age colonies are maintained. The old trees identified in this area were indicator tree species with historical value. Representatively, Pinus densiflora for. multicaulis Uyeki, located in Nokjiwon Garden, is presumed to have been preserved as one of Pinus densiflora for. multicaulis Uyeki planted next to Yongmundang, and has a historicality that has been used as a photo zone at dinners for heads of state and important guests. Lastly, in order to continuously preserve and manage the value of Gyeongbokgung Palace in Blue House, it is urgent to clarify the space value through excavation of historical materials in Japanese colonial era and establish a hierarchy of garden archaeology by era. In addition, the basis for preserving the historical landscape from the Joseon Dynasty to the modern era from Gyeongbokgung Palace should not damage the area of the old giant trees, which has been perpetuated since the past, and a follow-up study is needed to investigate all the forests in Blue House.

• Journal of Digital Convergence
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• v.16 no.5
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• pp.213-220
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• 2018

The automobile industry in Korea is a very large industrial sector. Nowadays, as the interest in low carbon green growth grows all over the world, it is time to actively secure future competitiveness of the automobile industry. Therefore, it is essential to study consumer attitudes and intentions for electric vehicles at the time when technological and social changes are expected. This study was conducted to investigate the acceptability and preference of electric vehicle for 250 people. The results are as follows. As the monthly income and the number of residents increased, the decision was made to accommodate the electric vehicle. The larger the effect of the electric vehicle on the consumers, the more the electric car decided to accommodate the electric car. In addition, three demographic characteristics (monthly income, number of residents, residence type) showed that there was a difference in satisfaction of electric vehicles. As a result of analyzing the satisfaction level of the electric vehicle, it was found that the electric vehicle has a satisfactory effect on the consumer, the electric vehicle is about 3.5 times more satisfying, and the larger the interest of the electric car is, the more the electric car is about 2.1 times.

• Korean Journal of Community Nutrition
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• v.4 no.2
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• pp.175-185
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• 1999

This study was conducted among the university students to investigate the effects of working in an daytime and studying in an evening class on dietary behaviors and nutrient intakes. A 24-hour recall method was used along with food frequency questionnaires. The subjects were composed of three groups : 172 were in the daytime calss regular student group(RS), 178 were evening class students without a job(ESWOJ), and 140 were evening class students with a job(ESWJ). An average age of the ESWJ was 31 years old, which was 9 years older than the RS and 7 years older than the ESWOJ. The types of the residence were significantly different among the groups ; were seif-boarding 74% of the ESWJ stayed at home while 47% of the RS were self-boarding and 61% of the ESWOJ. The survey shows that while a great majority of the RS and ESWOJ has breakfast and supper at home, about 10% and 17% of the ESWJ ate breakfast and supper, respectively, at the cafeteria in their work place. The most frequently skipped meal was the breakfast in all groups. Approximately 9% of the ESWJ tended to skip the breakfast, while 27% of the RS and 33% of the ESWOJ did. It turns out that the mose common reason why ESWJ skipped meals was due to a lack of time. About 71% of the ESWJ ate out more than once a week compared to 57% and 62% of the RS and ESWOJ, respectively. Approximately 30% of the ESWJ ate out more than once a week compared to 57% and 62% of the RS and ESWOJ, respectively. Approximately 30% of the ESWJ spent less than 10 minutes at meal time, showing a hurried eating habit. The results show that the ESWJ tended to eat a variety of food s and eat less instant foods, but drink coffee more often compared to the other two groups. The results also show that in all groups, the intakes of energy, Ca, and vitamin A were lower than the Korean Recommended Daily Allowances(RDA). In addition to these nutrients, protein, vitamin B1, vitamin $B_2$, and niacin were also lower than the RDA in all make students, and Fe was lower than the RDA in all female students. Among the deficient nutrients, vitamin A showed the lowest % RDA : 48% in the male and 64% in the female students. Among the deficient nutrients, vitamin A showed the lowest % RDA ; 48% in the male and 64% in the female students. The intakes of Ca, Fe, and niacin in the ESWJ were significantly greater than those in the RS and ESWOJ groups, and the vitamin C intake in the ESWJ was greater than that in the ESWOJ(p<0.01). In conclusion, university students in all three groups have a serious imbalance in the nutrient intakes, and the evening class students with a daytime job have unhealthy dietary behaviors in the light of high frequency of eating out and heavy coffee drinking, a rushed eating pattern, and therefore showing a strong need of proper nutritional education for them.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.1
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• pp.35-41
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• 2004

The yeongok stream originates at the natural park, Mt. O-dae and flows to the East Sea of korea, normally maintaining I or II grade of water quality and its average water flux is 352,100 ㎥/d. However, the typhoon 'Rusa', which occured on 31 August 2002, changed its watercourse and configuration, and the ecosystem was deeply damaged. Moreover, the hydrological characteristics were once more transformed, and the ecosystem was secondarily damaged during repair-work of destroyed bridges and elevations. After the flood disaster, the species diversity diminished 17% for attached diatom and 44% for aquatic animals. However, the earth and sand, dug from river bed during intensive repair-work throughout the entire stream, made diversity drop to 32% for the diatom and the aquatic animals were wiped out. Especially, fishes were totally destroyed except for some species such as Moroco oxycephalus in the upper stream. The yeongok stream has little contamination source and short water residence time due to the short length and rapid slope, and consequently a temporary deterioration of water quality caused by repair-work may be rapidly recovered, but it needs a long time to restore the damaged ecosystem.

• The Korean Journal of Pharmacology
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• v.32 no.2
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• pp.269-281
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• 1996

Pharmacokinetics of prednisolone and prednisone undergoing reversible interconversion were analyzed from the model including this metabolic process. Blood samples were drawn serially upto 12 hours after I,V. bolus injection of 1 mg/kg prednisolone sodium phosphate and prednisone into 8 dogs as a crossover manner. Plasma concentrations of those two steroids were simultaneously measured with the method of HPLC. After injection, plasma concentrations of administered prednisolone and prednisone were declined with a biexponential pattern and their metabolic partner was rapidly formed. Plasma concentrations of those metaboite were decayed in parallel with their parent steroids throught the elimination phase. Apparent clearances of prednisolone and prednisone were $11.1{\pm}2.0\;ml/min/kg$ and $45.9{\pm}6.4\;ml/min/kg$, and they were underestimated by 29.4% and 33.6% compared to their real clearances$(15.7{\pm}4.4\;and\;69.2{\pm}17.7\;ml/min/kg)$ estimated using reversible interconversion model. Apparent volume of distribution of prednisolone$(1.32{\pm}0.43\;L/kg)$ and prednisone$(4.81{\pm}2.75\;L/kg)$ were overestimated by 53.5 and 52.7% and were compared to the real volumes $(0.86{\pm}0.30\;and\;3.15{\pm}2.13\;L/kg)$. Mean residence time of prednisolone$(2.0{\pm}0.61\;h)$ and prednisone$(1.74{\pm}0.74\;h)$ were much longer than the real sojourn time$(0.93{\pm}0.26\;and\;0.88{\pm}0.54\;h)$. Essential clearances In the reversible interconversion were greater as following orders: $Cl_{21}$(44.3 ml/min/kg) > $Cl_{20}$(24.2 ml/min/kg) > $Cl_{12}$ (7.9 ml/min/kg) > $Cl_{10}$(7.8 ml/min/kg). Estimated mean values of RF, EE, $%X^1_{ss}$ and $RHO^2_1$ were $0.31{\pm}0.10$, $1.49{\pm}0.23$, $69.3{\pm}16.7%$ and $0.65{\pm}0.10$, respectively. These results suggested that true pharmacokinetic parameters estimated from the model including reversible interconversion were significantly different from the apparent parameters estimated from the conventional mamillary model, and disposition of these two steroids seemed to be well explained by the model including reversible interconversion.