• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.8 s.338
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• pp.33-40
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• 2005

This paper presents a structure of the searcher using a diversity in array antenna systems operating in the cdma2000 1x signal environments. The new technique exploits the fact that the In-phase and quadrature components of interferers can respectively be viewed as an independent gaussian noise at each antnna element in most practical cdma signal environments. The proposed PN acquisition scheme is a singles-dwell PN acquisition system consisting of two stages, that is, the searching stage and the verification stage. The searching stage independently correlates the receiver multiple signals with PN generator of each antenna element for obtaining the synchronous energy at the entire region. Then, the searching results of each antenna element are non-coherently combinind. The verification stage compares the searching energy with the optimal threshold, which is predesigned in the lock detector, and decides whether the acquisition is successful or fail. In this paper, we analyzed the effect of tile diversity order to determine the mean acquisition time. In general, it is known that the mean acquisition time significantly decrease as the number of antenna elements increases. But, as the diversity order goes up, the enhancement of the performance is saturated. Therefore, to decrease the mean acquisition time of the searcher, we must design the optimal array antenna systems by considering the operating SNR range of the receiver, the probability of detection $P_D$ and that of false alarm $P_{FA}$ . The Performance of the proposed PN acquisition scheme is analyzed in frequency selective Rayleigh fading channels. In this paper, the effect of the number of antenna elements on PN acquisition scheme is shown according to the probability of detection $P_D$ and that of false alarm $P_{FA}$.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.40 no.6
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• pp.47-55
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• 2003

In this paper, we propose a new approach to detect peculiar features of license plates using intensity vector and composite color component in order to extract license plates from parking regulation images, which is captured in various locations around the front or the rear of cars at various times and places, and in which complex background is included. We fundamentally use both features that intensity value repeats frequently increasing and decreasing because intensity is obviously different at numerics and background, and that color is uniform in the area of license plates. First, we search each row at regular intervals starting from the bottom of a license-plate image, and we set up a rough region for a certain zone in which tile sign of intensity vector changes frequently enough and color of license plate is detected enough, assuming it as a candidate location of a license plate. And then, we extract an elaborate area of a license plate by projecting vertical edges horizontally and vertically. Here, type of cars, such as the urinate and the public, is easily classified according to the color of extracted plates. We used 200 actual regulation images, which are captured at various times and places, to evaluate the performance of the proposed method. As a result, the proposed method showed extraction rate of 96%, which is 9% higher than the previous method using only intensity vector.

• Journal of the Korea Concrete Institute
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• v.15 no.1
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• pp.134-142
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• 2003

Autogenous shrinkage, a significant contributor of early-age cracking of high strength concrete (HSC), must be avoided or minimized from an engineering point of view. Therefore, it is necessary to study how to reduce and to predict autogenous shrinkage with respect to tile control of early-age cracking. In this study, autogenous shrinkage of HSC with various water-binder ratio (W/B) ranging from 0.50 to 0.27 and fly ash content of 0, 10, 20, and 30% were investigated. Based on the test results, thereafter, a prediction model for autogenous shrinkage was proposed. Test results show that autogenous shrinkage increased and more rapidly developed with decreasing the W/B. Also, the higher fly ash contents, the smaller autogenous shrinkage. In particular, even if much autogenous shrinkage occurs at very early-ages, stress may not be developed while the stiffness of concrete is low. In order to consider the change of concrete stiffness, the transition time referred as stiffening threshold, was obtained by monitoring of ultrasonic pulse velocity evolution and considered in the autogenous shrinkage model. From a practical point of view, the proposed model can be effectively used to predict autogenous shrinkage and to estimate stress induced by autogenous shrinkage.

• Journal of Korean Academy of Nursing
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• v.3 no.1
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• pp.41-51
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• 1972

In this article, the writer attempted to study the followings: (1) mother's knowledge of milk feeding (including method of sterilization, formula and feeding) (2) reasons of artificial feeding (3) how much mothers are concerned about their artificial feeding infants (4) condition of growth and development of artificial feeding infants. As the object of study, 96 mothers with artificial feeding infants, who had consulted dep't of pediatrics of two Hospitals in Seoul (Korea Hospital and Med. College Woo Suk Hospital, Korea Uni.) and well baby clinic of the two Health Centers (Sung Dong and Dongdaemoon), were randomly sampled. The data were treated by the statistic method of chi-square and percentage, and come to the following conclusion. 1. Knowledge of milk feeding Sterilization: 70 percentages of mothers know about the milk sterilization (including bottle, nipple and instrument), but 55 percentages of them do not know the nipple sterilization correctly. Formula: 69 percentages of mothers follow the indicator or in accordance with doctor's directions, but 31 percentages do at their option by reasons that the baby often coughs up the milk, the baby is too small, the baby often has digestive troubles, or the baby grow fleshy heavily etc, except family economic problems. Feeding: only half of mothers know the correct feeding method, especially they do not know how to determine the heat degree of milk and how to bubble up the baby correctly. They just do feeding according to the accepted usages. 2. Reasons of artificial feeding Of the reasons of artificial feeding, 18 percentages were caused by infants and 82 percentages by mothers. Most of the reasons are mainly due to the lack of breast milk and sufficient supply of nourishments rather than mother's deficiency or mother's abnormality. 3. Mother's concern for artificial feeding infants Mothers who are sharply concerned for their artificial feeding baby's growth and development: 63%, mothers who made the baby (artificial feeding infant) routine vaccinated: 81%, mothers who ear anxious about the baby's future personality forming : 68%, mothers who care about the baby's condition of nourishment; 60%, mothers who are anxious about tile selection of baby's food; 54%. 4. The growth and development of artificial feeding infants compared with Korean average infants. The artificial feeding infants are above the Korean average infants in stature by 1.21 centimeters and in weight by 0.3 kilograms. Conclusion: It has been said that there is no better food for infant than the breast milk. However, the artificial feeding has been used for the supplement of nourishments and as substitute food for the breast milk. And this artificial feeding could give the married women the chance to act in society and more opportunity to develop themselves and to work for others at home and other fields. Considering these advantages, artificial feeding should not be exclusive, but preferably should be more improved and inquired positively. And even in artificial feeding, what is most important is that mothers should recognize the requirement and need of artificial feeding clearly and correctly, and they should be accustomed to the correct knowledge and skills of artificial feeding in order to practice it appropriately. In some degree, they should be properly trained in school education process.

• Journal of Soil and Groundwater Environment
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• v.10 no.6
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• pp.68-74
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• 2005

This study was carried out to evaluate the feasibility of field-scale sequential soil washing process for remediation on Kyongsangnamdo D mine soils which was heavily contaminated by arsonic. Arsenic concentration of untreated soils was $321\pm32mg/kg$. By applying the basic operating condition which was proposed from several pilot-scale experiments, arsenic concentration of treated soils was reduced 2.04 mg/kg ($99\%$ removal efficiency). We optimized the basic operating condition (mainly on washing solution concentration, cut-off size, and mixing ratio) to improve efficiently and economically the field-scale sequential soil washing process. The resulting optimized conditions were that solution concentration is 0.2M HCl, 1.0M HCl, 1.0M NaOH, that the cut-off size is 0.15mm (seive $\sharp$100), and that the mixing ratio is 1 3. Also, the optimized pH value for soil washing effluent treatment was 6 (33 ppb), in which the precipitation disruption caused by supersaturation of the floe did not occur. Results of TCLP tests showed that arsenic concentration from the washed gravels was 1.043 mg/L, that from soils ND (not detected), and that from filter cakes 0.066 mg/L. Also, the water content as a percentage of dewatered sludges was low $(48\%)$ and so the dewatered sludges can be disposed by landfilling. Through these results, we can concluded that tile field-scale sequential soil washing process developed in this study is adopted for remediation of arsenic-contaminated soils.

• Journal of Preventive Medicine and Public Health
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• v.7 no.1
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• pp.131-138
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• 1974

The author has conducted survey on the status of physical growth and morbidity of the children for christian children's fund programme, as a means of collecting basic data for the anticipated establishment of a health planning. A total 345 children aged 9 to 16 underwent C.C.F. programme while as a control, a total of 480 children of same ages from the middle-class school children in Jeonju area was also studied. As results of survey conducted for a period of one month (form July 1 to 31, 1974) on a total 429 children in 347 households living in Jeonju area. I. Socio-economic background 1. By educational status of the children, 39.9 per cent of the total children was attending at primary school, 33.8 per cent in middle school and 15.6 per cent in high school. 2. The greatest proportion or 28.8 per cent of the household head were engaged in labor, 17.9 per cent in peddler and 13.2 per cent in retail. 3. As for the living standard of the households, low class constitued 90.1 per cent, middle and high classes only 9.9 per cent. 4. 39.5 per cent of the households had their own house, 39.1 per cent lived in rent deposit house or rooms and 14.6 per cent in monthly rented house and rooms. II. Physical growth and nutritional status 1. The growth of children for C.C.F. programme in terms of height was found to be slightly smaller than the school children. The ages frm 9 to 16 corespond to the 'secondary growth and replenishment period and this period was regarded to be the one most affected by environmental and nutritional factors of all the other periods of growth and developmet. 2. The body weight of the children for C.C.F. presented a quite different pattern from that of the school children. The above findings appeared thin-and-long stature from the famillies with higher living standard while those from the household with low standard of living had a short-and-plump one. 3. According to the values of Rohrer's index, the children of C.C.F carried a higher degree of 'replenishment' than the children in Jeonju area and adolesecence comes later for the girls under C.C.F. programme. III. Morbidity 1. The monthly prevalence rate was 110.0 per thousand persons for the children under C.C.F. programme. 2. The total number of case was classified by timing of the incidence as follws. 40.0 per cent was constituted by diseases carried over from tile previous month and 60.0 per cent by new incidences. 3. The diseases were broken down by W.H.O. disease classification into the greatest proportion or 39.1 per thousand person constituted by disease of the digestive system.

• Journal of Preventive Medicine and Public Health
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• v.2 no.1
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• pp.77-80
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• 1969

In the cities nowadays, the dwelling conditions of Cackroach are provided by use of various kinds of construction material, installation of heating and cooling facilities that maintain moderate temperature, filthy sanitation, and lack of knowledge about insect as mechanical Vector. Cakroach is infectious disease Vector, and it proves to be of much importance in the public health. Considering such importance, the author has surveyed the distribution of Cackroach in the housing areas of Seoul City from May 1969 to the end of August 1969, and has come to the following conclusion: 1. House dwelling Cackroach collected in the City of Seoul are of two species, i. e. Blatella Germanica Linneaus and Periplaneta Japonica Karny. 2. Most of cackroach collected in Seoul are Blatella Germanica Linneaus and they are distributed in whole area of Seoul while that of Periplaneta Japonica Karny is distributed only in the limited area. 3. Dwelling places of Blatella Germanica Lineaus are in grog shop, Korean food restaurants, bakery shops, and patient rooms in hospitals. Many of them are found in tile kitchens and dining rooms of restaurants, and tearooms. They live in groups at older houses with much crack, warm and humid places. 4. For method of collection, the hand collection was the most effective. In trap collection during the day time, when the trap is placed at the narrow corners off the ground after confirming the dwelling places of cackroach, the match trap was more effective than the flask trap in collecting. In case of collecting during the night time, the flask trap was much more effective method than the match trap.

• Journal of Preventive Medicine and Public Health
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• v.2 no.1
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• pp.61-76
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• 1969

A review has been made of mortality trends in Korea from 1958 to 1967 analyzing the data by sex, age and cause of death. The crude death rates and age specific death rates were estimated by the model of N. Keyfitz life table which had been developed by the data of the 1960's national census. The cause specific death rates shown in this article are based on the following: all deaths occurring in the death-registration are expressed as a numberator, while the denominator was estimated from the regular national census data by interpolation method. It is estimated that only an average of about 40% of deaths which occurred during a year were registered during 1958 to 1967. The validity and the reliability of the diagnosis of causes of death seem to be extremely poor in this country. Therefore the cause specific death rates in this article are aimed to reveal trends of causes of registered death ana not for the actual level of death rates. For 10 years very interesing mortality trends were observed : 1. The trend in the crude death rates was downward slowly. 2. The estimated death rate for the infant in 1960 was still high up to 100 per 1,000. 3. The rates for mortality attributed to such infectious diseases as pneumonia, bronchitis, gastroenteritis and measles decreased an average 40-60%. 4. The death rates for over-all tuberculosis decreased only 9.8%. 90% of the decrease was contributed by those in the less-than-15 year age group. 5. The death rates for chronic diseases, such as vascular diseases affecting the central nervous system, malignant neoplasm, major heart diseases and all accidents rose about 40-60%. 6. The rank order of the 10 leading causes of death showed large changes over the years, except for pneumonia and tuberculosis which occupyed 1st and 2nd places respectively. Vascular diseases affecting the central nervous system moved from 5th to 3rd place and malignant neoplasm from 6th to 4th place, The major heart diseases moved from 10th to 6th place and all accidents from 10th to 7th place. On tile other hand, gastroenteritis moved from 3rd to 5th place and influenja from 4th to 8th place.

• Nuclear Engineering and Technology
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• v.3 no.3
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• pp.148-154
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• 1971

Some formulae have been derived for the handy calculation of the formation of radioisotope when a reactor is operated regularly on a usual on-off pattern. In particular, the case of isotope production with the present operation condition of tile Korean reactor, which is in operation for 8.2 hours from Monday to Thursday and is not operated on friday and Sunday but is back in operation on Saturday only for 3.2 hours, is discussed herein with special emphasis. Should there be no secondary nuclear reaction resulting in the transformation of produced nuclide, the formula for the calculation of its activity could be derived as follows: (equation omitted) where A: activity (dps), $\Phi$： neutron flux (n cm$^{-2}$ sec$^{-1}$ ), No : number of atoms before the irradiation, $\sigma$ : activation cross section ($\textrm{cm}^2$), λ : disintegration constant of the radioactiveisotope formed (hr$^{-1}$ ), t : elapsed time of target in the reactor (hr), n : number of elasped days of target in the reactor, m : number of days from the first day of sample irradiation to Friday, s, r, q: number of weekday of Friday, Saturday and Sunday, respectively. Since the above formula consists of many invariables on the whole, the activity of each radioisotope to be produced can he easily and conveniently made available from the chart in advance which is made of the invariable terms calculated.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.5
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• pp.499-507
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• 2004

We have studied tile detection techniques, which can determine the location and the weight of an intruder into infrastructure, by using fiber-optic ROTDR (Rayleigh optical time domain reflectometry) sensor and fiber-optic BOTDA (Brillouin Optical time domain analysis) sensor, which can use an optical fiber longer than that of ROTDR sensor Fiber-optic sensing plates of ROTDR sensor, which arc buried in sand, were prepared to respond the intruder effects. The signal of ROTDR was analyzed to confirm the detection performance. The constructed ROTDR could be used up to 10km at the pulse width of 30ns. The location error was less than 2 m and the weight could be detected as 4 grades, such as 20kgf, 40kgf, 60kgf and 80kgf. Also, fiber optic BOTDA sensor was developed to be able to detect intrusion effect through an optical fiber of tells of kilometers longer than ROTDR sensor. fiber-optic BOTDA sensor was constructed with 1 laser diode and 2 electro-optic modulators. The intrusion detection experiment was peformed by the strain inducing set-up installed on an optical table to simulate all intrusion effect. In the result of this experiment, the intrusion effort was well detected as the distance resolution of 3m through the fiber length of about 4.81km during 1.5 seconds.