• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.6
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• pp.763-774
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• 2023

The water availability in a river is related to the return flow of residential water. However it is still difficult to determine the exact return flow. In this study, the residential water-cycle system is defined as a process consisting of water inflow, water transfer and water outflow. The study area is Hampyeong-gun, Jeollanam-do, and is set as a single inflow to a single outflow through the water-cycle system after classification of complete and incomplete measurement points. The time-series prediction models(ARIMA model and TFM) are established with daily inflow and outflow data for 6 years. Inflow and outflow are predicted by dividing into training and test periods. As a result, both models show the feasibility of short-term prediction by deriving stable residuals and securing statistical significance, implementing the preliminary form of the water-cycle system. As a further study, it is suggested to predict the actual return flow of the target basin and efficient water operation by adding input factors and selecting the optimal model.

• Journal of The Korean Astronomical Society
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• v.45 no.4
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• pp.85-91
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• 2012

Astronomical data making such as forming a calendar, period of day, determining the time of rising/setting of the sun and the onset of twilight are essential in our daily lives. Knowing the calendar day of the past is particularly crucial for studying the history of a clan or a nation. To verify previous studies in the calendar day of the Joseon dynasty (1392 - 1910), we investigate the sexagenary cycle of the new moon day (i.e., the first day in a lunar month) by using sources such as results of the calculations using the Datong calendar (a Chinese Calendar of the Ming Dynasty) and the data of Baekjungryeok (a Perpetual Calendar; literally, a one hundred-year almanac). Compared with the study of Ahn et al., we find that as many as 17 sexagenary cycles show discrepancies. In the cases of nine discrepancies, we find that the sexagenary cycles of this study are identical to those of the almanacs at that time. In addition, we study five sexagenary cycles by using the historical accounts of Joseon Wangjo Sillok (Annals of the Joseon Dynasty), Seungjeongwon Ilgi (Daily Reports of Royal Secretariat), Chungung Ilgi (Logs of Crown Prince), and so forth. For the remaining discrepancies, we present historical literature supporting the results of this study. This study will greatly contribute to the identification of the lunisolar calendar days during the Joseon dynasty as the dates of the modern (i.e., Gregorian) calendar.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.138.2-138.2
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• 2011

Astronomical data such as calendar day and time of rising/setting of the sun and onset of twilight are essential in our daily lives. Knowing the calendar day of the past is particularly crucial for studying the history of a clan or a nation. To verify previous studies on the calendar day of the Joseon dynasty (1392 - 1910), we also investigated the sexagenary cycle of the new moon day (i.e., the first day in a lunar month) using different sources: results of the calculation by the Datong calendar (a Chinese Calendar of the Ming Dynasty) and data of Baekjungryeok (a Perpetual Calendar - literally, a one hundred-year almanac). Compared with the study of Ahn et al., we have found that as many as 17 sexagenary cycles show discrepancies. In the case of nine discrepancies, we found that the sexagenary cycles of this study are identical to those of the almanacs at that time. In addition, we study six sexagenary cycles by using the historical accounts of Joseon Wangjo Sillok (Annals of the Joseon Dynasty), Seungjeongwon Ilgi (Daily Records of Royal Secretariat), Chungung Ilgi (Logs of Crown Prince), and so forth. We present historical materials supporting the results of this study for the remainder. In conclusion, we think that this study will greatly contribute to the comparison between luni-solar calendar days during the Joseon dynasty and those in the modern (i.e., Gregorian) calendar.

• Journal of Environmental Science International
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• v.6 no.2
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• pp.95-106
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• 1997

The characteristics on the transtion probabilities and periodicity for the daily precipitation occurrence in Korean peninsula are investigated by applying the Markov chain properties to daily precipitation occurrence. In order to examine the responses of Markov Chain properties to the applied period and their magnitudes, three cases (Case A: 1956~ 1985 at 14 stations, Case B: 1965~ 1994 at 14 stations, and Case C: 1985~ 1994 at 63 stations) are considered In this study. The transition probabilities from wet day to wet day for all cases are about 0.50 and in summer, especially July, are higher. In addition, considering them in each station we can find that they are the highest at Ullung-do and lowest at Inchon for all cases. The annual equilibrium probabilities of a wet day appear 0.31 In Case A, 0.30 Case B, and 0. 29 Case C, respectively. This may explain that as the data-period used becomes shorter, the higher the equilibrium probability is. The seasonal distributions of equilibrium probabilities are appeared the lowest(0.23~0.28) in winter and the highest(more than 0.39) in spring and monthly in .truly and in October, repectively. The annual mean wet duration for all cases is 2.04 days in Case A, 1.99 Case B, and 1.89 Case C, repectively. The weather cycle obtained from the annual mean wet and dry duration is 6.54~6.59 days, which are closely associated with the movement of synoptic systems. And the statistical tests show that the transitions of daily precipitation occurrence for all cases may have two-state first Markov chain property, being the stationarity in time and heterogeneity in space.

• Journal of Astronomy and Space Sciences
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• v.40 no.2
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• pp.45-57
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• 2023

This study examined the effect of solar flux (F10.7) and sunspots number (R) on the daily variation of equatorial electrojet (EEJ) and morning/afternoon counter electrojet (MCEJ/ACEJ) in the ionospheric E region across the eight longitudinal sectors during quiet days from January 2008 to December 2013. In particular, we focus on both minimum and maximum solar cycle of 24. For this purpose, we have collected a 6-year ground-based magnetic data from multiple stations to investigate EEJ/CEJ climatology in the Peruvian, Brazilian, West & East African, Indian, Southeast Asian, Philippine, and Pacific sectors with the corresponding F10.7 and R data from satellites simultaneously. Our results reveal that the variations of monthly mean EEJ intensities were consistent with the variations of solar flux and sunspot number patterns of a cycle, further indicating that there is a significant seasonal and longitudinal dependence. During the high solar cycle period, F10.7 and R have shown a strong peak around equinoctial months, consequently, the strong daytime EEJs occurred in the Peruvian and Southeast Asian sectors followed by the Philippine regions throughout the years investigated. In those sectors, the correlation between the day Maxima EEJ and F10.7 strengths have a positive value during periods of high solar activity, and they have relatively higher values than the other sectors. A predominance of MCEJ occurrences is observed in the Brazilian (TTB), East African (AAE), and Peruvian (HUA) sectors. We have also observed the CEJ dependence on solar flux with an anti-correlation between ACEJ events and F10.7 are observed especially during a high solar cycle period.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1503-1510
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• 2014

Breast cancer bone metastasis causing severe morbidity is commonly encountered in daily clinical practice. It causes pain, pathologic fractures, spinal cord and other nerve compression syndromes and life threatening hypercalcemia. Breast cancer metastasizes to bone through complicated steps in which numerous molecules play roles. Metastatic cells disrupt normal bone turnover and create a vicious cycle to which treatment efforts should be directed. Bisphosphonates have been used safely for more than two decades. As a group they delay time to first skeletal related event and reduce pain, but do not prevent development of bone metastasis in patients with no bone metastasis, and also do not prolong survival. The receptor activator for nuclear factor ${\kappa}B$ ligand inhibitor denosumab delays time to first skeletal related event and reduces the skeletal morbidity rate. Radionuclides are another treatment option for bone pain. New targeted therapies and radionuclides are still under investigation. In this review we will focus on mechanisms of bone metastasis and its medical treatment in breast cancer patients.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1A
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• pp.75-89
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• 2006

This paper presents a practical and realistic Life-Cycle Cost (LCC) optimum design methodology of steel bridges considering time effect of bridge reliability under environmental stressors such as corrosion and heavy truck traffics. The LCC functions considered in the LCC optimization consist of initial cost, expected life-cycle maintenance cost and expected life-cycle rehabilitation costs including repair/replacement costs, loss of contents or fatality and injury losses, road user costs, and indirect socio-economic losses. For the assessment of the life-cycle rehabilitation costs, the annual probability of failure which depends upon the prior and updated load and resistance histories should be accounted for. For the purpose, Nowak live load model and a modified corrosion propagation model considering corrosion initiation, corrosion rate, and repainting effect are adopted in this study. The proposed methodology is applied to the LCC optimum design problem of an actual steel box girder bridge with 3 continuous spans (40 m+50 m+40 m=130 m), and various sensitivity analyses of types of steel, local corrosion environments, average daily traffic volume, and discount rates are performed to investigate the effects of various design parameters and conditions on the LCC-effectiveness. From the numerical investigation, it has been observed that local corrosion environments and the number of truck traffics significantly influence the LCC-effective optimum design of steel bridges, and thus realized that these conditions should be considered as crucial parameters for the optimum LCC-effective design.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.1
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• pp.31-41
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• 1999

To evaluate the effectiveness of intrauterine insemination (IUI) in the treatment of infertility, timed-intercourse and intrauterine insemination by husband in stimulated cycles with clomiphene citrate and gonadotropins were compared in a total of 105 cycles. Patients received 100mg of clomiphene citrate daily for 5 days starting on day 3 of the menstrual cycle followed by hMG or FSH. Doses of exogenous gonadotropins were adjusted by the follicular development and concentrations of serum estradiol $(E_2)$. More than 3 follicles reaching >16 mm were present in the ovary, 5,000 IU of hCG was administered intramusculary. Patients received a maximum of three intercourse or IUI cycles for the treatment. Severe male (<$10{\times}10^6$ motile sperm) or age factor (>39 y) patients were excluded in this study. Pregnancy was classified as clinical if a gestational sac or fetal cardiac activity was seen on ultrasound. The overall clinical pregnancy rates were 17.1% per cycle (18/105) and 21.2% per patient (18/85). The pregnancy rates (per cycle) were 17.5% (11/63) in intercourse and 16.7% (7/42) in IUI groups, respectively. IUI had no significant improvement in pregnancy rate compared with timed-intercourse. The multiple pregnancy rates were 11.1% (1 twin and 1 triplet). No patient developed ovarian hyperstimulation. Abortion rate was 28.6% (2/7) in IUI group only. The delivery and ongoing pregnancy rates were 15.2% per cycle (16/105) and 18.8% per patient (16/85). There were no differences in age, duration of infertility, follicle size and level of estradiol $(E_2)$ on the day of hCG injection in pregnant and non-pregnant groups. However, total doses of gonadotropins were higher in pregnant group than in non-pregnant group (p<0.01). Pregnancy rate was not affected by ovulatory status at the time of insemination. These results indicate that well timed-intercourse in stimulated cycles is as effective as IUI for infertile couples.

• The Korean Journal of Archival Studies
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• no.5
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• pp.3-37
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• 2002

Today the market of EDMS is esteemed more than 100 billions won. It signifies a comming of age of electronic records. The traditional archival theories which are based on the paper records are confronted with a new challenge. In some leading countries of archival studies reorientation of archives management has been tried by a number of distinguished specialists such as Bearman and Hedstrom since 10 years. As a consequence new paradigm of archival theories has been developed. Also in Korea this new paradigm has been introduced by some expert such as Lee, Sang-Min, Sul, Moon-won, Lee, Seung-Eok. However their arguments are too general to offer a concrete clue for new paradigm. Faced by new age of electronic records, it's important to start a discussion for the reasonable methods of electronic records management at once. The most drastically changed part of record management by the electronic technique is the life-cycle of records. The commonly practiced three-stage life-cycle is to be reduced to the two-stage life-cycle, and the concept of the spatial movement of records is to be changed. It can be also pointed that the public emerges as user from the early creating stage of records beyond time and space. Thus is can be said that the method of the management features dynamic and cohesive. The method of appraisal must be also changed and reproduced, so that it can reflect the various levels considering dynamics of the electronic records. Supposedly it will be a core factor that causes the change of methodology in records management with the change of life-cycle theory. It must be noted that various subjects would be involved in the work of classification and description over time and space and that feedback between them is of important. Description also tends to be made at the crating stage of records and structured dynamically. It results from the change of life-cycle and the introduction of the concept of continuum. Such trend allows us to start discussions on the assumption that description of both creator and archival professionals act together an important role. Of course, it is linked with the methodology in which most descriptions are made automatically at the early drafting stage of the structure. The meat date is formed on the assumption that there should be feedback between areas of automatic description, description of creators and archival professionals. The most important thing in description is to develop a suitable way how it is structured. An alternative must be offered for managing data set. As iweb that is being operated by Myongji university shows, records created in daily business are managed not as electronic records but as date base. This is because they exist outside the repository in the EDMS system. Since data set often has various sources, an alternative for classification needs to be developed. It is now likely that database is filed according to the created year to be transferred automatically to the repository. Over a long-term the total management of database, electronic records and electronic information will be a topic. A right direction of new paradigm will be found for both iweb and E-government, when practice and studies of theories are combined and interacted.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.5 no.2
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• pp.147-159
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• 1995

This study was conducted to introduce fundamental data of hand-arm vibration and noise exposure levels with impact wrenches(double-hammer impact wrenches and oil-pulse impact wrenches) used in automobile assembly lines considering the process variables and tool variables. In studing, products per day, required time screwing the bolts or nuts per bolts or nut were considered as process variables, and capacity of bolts or nuts, air consumptions per minute, tool weights, RPM were considered as tool variables. Hand-arm vibration levels of 3 axis in each hand were measured using the instruments compling with ISO/DIS 5349 and noise levels were measured using a noise logging dosimeter. The results were as follows : 1. Required time to screwing the bolt or nut by oil-pulse impact wrenches is shorter than double-hammer impact wrenches but total daily exposure time of oil-pulse impact wrenches was higher than double-hammer impact wrenches because the number of bolts or nuts per cycle was many. 2. Oil-pulse impact wrenches have been used to screwing the large bolt or nut in comparing with double-hammer impact wrenches and required time to screwing the bolts or nuts were shorter than double-hammer impact wrenches because oil-pulse impact wrenches were using high RPM and large air consumption per minute. Noise level of oil-pulse impact wrenches was 8 dB(A) lower than double-hammer impact wrenches. 3. Dominant hand-arm vibration levels of double-hammer impact wrenches in each hand were $8.24m/sec^2$ of Zh axis in right hand and $9.60m/sec^2$ of Xh axis in left hand. Dominant hand-arm vibration level of oil-pulse impact wrenches in each hand was $2.59m/sec^2$ of Xh axis in right hand and $3.23m/sec^2$ of Yh axis in left hand. 4. In double-hammer impact wrenches, corresponding hand-arm vibration levels of Xh, Yh, Zh axis in left hand were higher than hand-arm vibration levels of right hand in 3 axis. In oil-pulse impact wrenches, Xh axis of right, Yh axis of left, Zh axis of left were higher than the corresponding hand-arm vibration levels of Xh, Yh, Zh axis in right and left hand. 5. Correlation coefficients among Xh, Yh. Zh axis of right and left hand hand-arm vibration levels in double-hammer impact wrenches and oil-pulse impact wrenches were commonly high in Yh axis and correlation coefficients of Yh axis in double-hammer impact wrenches and oil-pulse impact wrenches were 0.76 and 0.86,respectively. 6. As a measure repetitiveness, plotting total daily exposure time with the number of bolts or nut per cycle, direct correlation was shown between repetitiveness and hand-arn vibration exposure, and correlation coefficient between the number of bolts or nut per cycle and total daily exposure time in double-hammer impact wrenches, oil-pulse impact wrenches were 0.84 and 0.50, respectively. 7. Considering the total acceleration level and tool variables in double-hammer impact wrenches and oil-pulse impact wrenches, air consumption in right hand, and bolt or nut capacity in left hand were commonly the variable that explainability was high. Considering the noise and tool variables in double-hammer impact wrenches and oil-pulse impact wrenches, air consumption per minute was commonly the variable that explainability was high.