• Journal of architectural history
• /
• v.20 no.3
• /
• pp.7-22
• /
• 2011

With the accumulations of outcomes from archaeological excavations of mountain fortress of three kingdoms period, there have been studies about time-periodic territory range of mountain fortress, difference in the way(method) of construction, defence system and so on from various points of view. This is an empirical study on the construction method of the valley part of stone fortress. First of all, it is required to secure large quantity of fresh water for those who lived at mountain fortress. Especially when builders of fortress construct a fortification at the valley part of stone fortress, in advance they must sufficiently consider several options including the establishment of sustainable water resources. First, when it comes to build a fortification on a ridge[or a slope] of a mountain, you have only to consider a vertical stress. However, when it comes to build a fortification at the valley part of a mountain, You must have more sufficient preparations for the constructing process. Because there are not only a vertical stress but also a horizontal pressure simultaneously. Second, a fortification of mountain fortress built by using unit building stone is a structure of masonry construction like brick construction, and the valley part of it is where the construction of the fortification begins. Third, when it comes to build a fortification at the valley part of a mountain, it seems that they use a temporary method such as coffer dam in oder to prevent the collapse of the fortification due to heavy rain. Furthermore, in response to a horizontal pressure a fortification is built by the way of its plane make an arch, or by piling up the soil with the plate method(類似版築) and earthen wall harder method(敷葉) they increase cross-sectional area of the fortification and its cutoff capacity. In front direction they put the reservoir facility for the fear that the hydraulic pressure and earth pressure are directly transmitted to the fortification. The process of constructing the fortification at the valley part of a mountain is done in the same oder as follows; leveling of ground(整地) ${\Rightarrow}$ construction of coffer dam ${\Rightarrow}$ construction of the fortification between the both banks of the valley ${\Rightarrow}$ construction of the fortification at bottom part of spill way(餘水路) between the both banks of the valley ${\Rightarrow}$ construction of spill way(餘水路) & reservoir facility ${\Rightarrow}$ construction of the fortification at upper part of spill way between the both banks of the valley. Coffer dam facility seems to be not only the protection device on occasion of flood but also an important criterion to measure the proper height of spill way or tailrace(放水路). This study has a meaningful significance in that it empirically examines the method of reduction of the horizontal pressure which the fortification at the valley part of a mountain takes, the date the construction was done, and wether the changes in climate such as heavy rainfall influence the process of construction.

• Korean Journal of Plant Tissue Culture
• /
• v.28 no.3
• /
• pp.135-140
• /
• 2001

A series of studies were carried out to establish micropropagation system, using airlift bioreactors (ebb $\varepsilon$ flood type, 5 L), of Lilium oriental hybrid 'Casa Blanca'. The bulblets with swollen basal plate were formed from bulb scales, then proliferated to bulblet clusters with swollen basal plate. Finally normal bulblets were formed from the sections. Bulblet formation and proliferation with swollen basal plate were not accomplished entirely in liquid culture of 5 L airlift bioreactors, but leafy bulb scales grew vigorously. Bulblet clusters with swollen basal plate were proliferated by periodic immersion culture. Bulblet proliferation was not affected by light, but scale leaves grew under light. MS medium containing 2.0 mg/L benzyl adenine (BA) and 0.3 mg/L indole acetic acid (IAA) was favorable to the bulblet proliferation with swollen basal plate. In liquid culture of 5 L bioreactors, bulblets from bulblet sections with swollen basal plate grew vigorously on MS medium with 70 g/L sucrose. It was effective for bulblet growth to replace the new medium after 8 weeks in culture during 16 weeks of cultural period. 15 g injection of bulblet sections as a cultural material was suitable for bulblet growth in 5 L bioreactors.

• Journal of Preventive Medicine and Public Health
• /
• v.10 no.1
• /
• pp.109-117
• /
• 1977

The improvement of civil registration reguires continuous study rather than periodic efforts. More and better statistics, however, are urgently required to formulate development programs and planning. Data obtainable from the civil registration are usually marred by errors of omission which are difficult to correct. This study aimed at finding out the problems occuring when a set of crude birth registration data in a rural area is used. Data Sources of this study are: 1) For birth registration: government birth registration records obtained from myun office and other government offices. 2) For the actual number of births: birth and child records from the Kang Wha Community Health Project The study area is Sunwon Myun and Naega Myun in Kang Wha Gun, Gyunggido. The referrance period for the accumulated data is one full year: Jan. 1st 1975-Dec. 31st 1975 Major findings are as follows: If the number of registered births is compared with the actual number of births which occured in the target area, the former is far greater than the latter. The general assumption usually is, that the actual number of births exceeds the registered number of birth in Korea. The observation from this specific study in this specific target area, shows the opporsite trend. The number of births which were registered is 550. This is more than two times as much as the number of births which actually occured during the year of 1975 in the study area namely 256. The difference comes mainly from the fact that many cases of births from other areas were registered in the target area. In other words birth is not registered where it occured but where the permanent residence adress is. Among 550 births registered in the target area 66% did not occur in the target area. Only one third of all registered births were registered within the legal period for birth registration which is 2 weeks. 34% of the registered births actually occured in 1974, but were registered in 1975. In 55% of the cases a difference was observed between the actual date of birth and the registered date of birth. From the 256 births which occured in the target area, only 153 births (59%) were registered at the myun office and the remaining 130 births (41%) were not resistered there in the year of study. 6% of the 550 cases listed as registered have no seperate registration sheets. Nevertheless, they definitly have been registered in the birth list at the myun office. 3% of the 550 cases are not recorded in this list but have a separate registration sheet at the myun office. In conclusion, birth registration data have many errors and problems. Their usefulness as. a source for vital and other statistics should be reconsidered. A series of sound methological studies will be necessary to establish their actual usefulness. A continuous and permanent compulsory system of birth recording is needed.

• Journal of the Korean Society of School Health
• /
• v.12 no.2
• /
• pp.305-319
• /
• 1999

The objective of this study were to evaluate the relation between post-examination management states of dental caries in elementary school students and a mother's dental health beliefs. We systematically chose 10 elementary school in urban and rural areas of Chungnam Province and determined the first class students of 5 and 6 grade in each school as study subjects. Among 837 participants, 669 students were diagnosed with dental caries after a 1998 periodic dental health examination was answered completely and analysed. The contents of the questionnaire for students were general characteristics, dental health behaviors, notification factors, treatment factors. Their mothers were surveyed by another questionnaire. The contents of the questionnaire for mothers were also general characteristics, dental health behaviors, and dental health beliefs. The result of this study were as follows 1. The prevalence of dental caries was 65.0% and there was no significant difference between urban and rural areas. 2. Meanwhile, 63.8% of students in urban areas knew the examination result through a doctor's explanation, 52.4% of students in rural areas learned through a school notification letter, 82.9% of all the students let their parents know of their dental caries. 3. Among the dental caries group, 36.3% of the students were treated as for treatment, most students in urban areas visited a dental clinic, but those in rural areas visited the dental dept of a public health center as for the treatment time, 35.9% of the students were treated immediately after the examination. 4. 44.9% of those treated answered that they felt they needed treatment; 67.2% of those not treated answered that they considered the treatment as a bother and unnecessary due to no pain. 5. Overall, the scores in the dental health beliefs in mothers were low. Especially among the 5 items of susceptibility and seriousness, the scored were very low but the benefit was high. Logistic regression analysis showed that the treatment of a child's dental caries was significantly associated with low scores of benefit in those untreated and high scores among those treated. Considering these results, health education to stimalate a mother's susceptibility and seriousness in health beliefs and for students to learn the need for treatment, including a more detailed post exam management system at the school level should be considered for a higher treatment rate.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.2
• /
• pp.293-299
• /
• 2014

Although the functional ingredient has been evaluated based on scientific evidence by the Ministry of Food and Drug Safety (MFDS), the levels of scientific evidence and consistency of the results might vary according to the emerging data. Therefore, a periodic re-evaluation may be needed in some functional ingredients. In this study, we re-evaluated the scientific evidence for the joint health of glucosamine as a functional ingredient in health functional food. Literature searches were conducted using Pubmed, Cochrane, KISS, and IBIDS databases with the search term of glucosamine in combination with osteoarthritis. The search was limited to human studies published in English, Korean and Japanese. Using the MFDS's evidence based evaluation system for scientific evaluation of health claims, 34 human studies were identified and reviewed in order to evaluate the strength of the evidence supporting the relation between glucosamine and joint health. Among the 34 studies, significant effects for joint health were reported in 28 studies, and their daily intake amount was 1.5 to 2 g. Eleven out of 34 studies were identified, excluding severe radiographic osteoarthritis, and ten from those eleven studies reported significant effects for joint health. Based on this systematic review, we concluded that there was possible evidence to support a relation between glucosamine intake and joint health.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.42 no.12
• /
• pp.1013-1019
• /
• 2014

Solid-liquid Phase Change Material(PCM) as a thermal control hardware for the electro-optical payload of low earth orbit satellite is numerically studied which can be substituted with Thermal Buffer Mass(TBM). The electro-optical module in LEO satellite is periodically work and high heat is dissipated during the imaging period, however, the design temperature range is very tight and sensitive. In order to handle this problem TBM is added and as a result the time constant of the module temperature increases. TBM is made of Al6010 and its mass directly affects the system design. To save the mass PCM is suggested in this study. The latent heat of melting or solidification is very high and small amount of PCM can play a role instead of TBM. The result shows that only 12% of TBM mass is enough to control the module temperature using PCM.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2002.07a
• /
• pp.25-37
• /
• 2002

The most important industrial application of gamma radiation in characterizing green compacts is the determination of the density. Examples are given where this method is applied in manufacturing technical components in powder metallurgy. The requirements imposed by modern quality management systems and operation by the workforce in industrial production are described. The accuracy of measurement achieved with this method is demonstrated and a comparison is given with other test methods to measure the density. The advantages and limitations of gamma ray densitometry are outlined. The gamma ray densitometer measures the attenuation of gamma radiation penetrating the test parts (Fig. 1). As the capability of compacts to absorb this type of radiation depends on their density, the attenuation of gamma radiation can serve as a measure of the density. The volume of the part being tested is defined by the size of the aperture screeniing out the radiation. It is a channel with the cross section of the aperture whose length is the height of the test part. The intensity of the radiation identified by the detector is the quantity used to determine the material density. Gamma ray densitometry can equally be performed on green compacts as well as on sintered components. Neither special preparation of test parts nor skilled personnel is required to perform the measurement; neither liquids nor other harmful substances are involved. When parts are exhibiting local density variations, which is normally the case in powder compaction, sectional densities can be determined in different parts of the sample without cutting it into pieces. The test is non-destructive, i.e. the parts can still be used after the measurement and do not have to be scrapped. The measurement is controlled by a special PC based software. All results are available for further processing by in-house quality documentation and supervision of measurements. Tool setting for multi-level components can be much improved by using this test method. When a densitometer is installed on the press shop floor, it can be operated by the tool setter himself. Then he can return to the press and immediately implement the corrections. Transfer of sample parts to the lab for density testing can be eliminated and results for the correction of tool settings are more readily available. This helps to reduce the time required for tool setting and clearly improves the productivity of powder presses. The range of materials where this method can be successfully applied covers almost the entire periodic system of the elements. It reaches from the light elements such as graphite via light metals (AI, Mg, Li, Ti) and their alloys, ceramics ($AI_20_3$, SiC, Si_3N_4, $Zr0_2$, ...), magnetic materials (hard and soft ferrites, AlNiCo, Nd-Fe-B, ...), metals including iron and alloy steels, Cu, Ni and Co based alloys to refractory and heavy metals (W, Mo, ...) as well as hardmetals. The gamma radiation required for the measurement is generated by radioactive sources which are produced by nuclear technology. These nuclear materials are safely encapsulated in stainless steel capsules so that no radioactive material can escape from the protective shielding container. The gamma ray densitometer is subject to the strict regulations for the use of radioactive materials. The radiation shield is so effective that there is no elevation of the natural radiation level outside the instrument. Personal dosimetry by the operating personnel is not required. Even in case of malfunction, loss of power and incorrect operation, the escape of gamma radiation from the instrument is positively prevented.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.4
• /
• pp.460-466
• /
• 2004

This study was undertaken with the aim to establish a reliable radioimmunoassay (RIA) system for urinary pregnanediol glucuronide (PdG) and to employ it for monitoring the reproductive status of dairy cows. Urine and blood samples were collected from the Holstein cows both pregnant and non-pregnant. The samples were then investigated for evaluating the relationship between progesterone ($P_{4}$) in blood and PdG in urine adjusted with or without urinary creatinine basis. Biweekly urine collection was employed for three cows in estrous and those artificially inseminated, while urine from pregnant cows was collected on a monthly basis. P_{4}$ and PdG levels were measured by enzymeimmunoassay (EIA) and RIA techniques, respectively. Our results indicated the sensitivity of PdG for RIA being 35 pg/tube and the recovery rate of 100%. Urinary creatinine concentrations also fluctuated within a day, but change at midday was not noteworthy. Regardless of the time of urination the change in concentrations of PdG was relatively smaller and did not vary significantly. The urinary PdG concentration showed periodic changes as that with serum P_{4}$ levels during the cow's estrus cycle. The correlation coefficient rose when creatinine level in urine was adjusted but the change was also not significant. The concentrations of PdG during the luteal phase were detected between 8.2 and 17.4 ng/ml, three to five times higher than that in the follicular phase. The concentration of PdG from pregnant cows (21 days after conception) was three to four times higher than in the nonpregnant cows. Our finding suggests that the determination of urinary PdG could be reliably employed for early pregnancy detection. The urinary PdG level continued to raise until 30 days pre-partum while the concentration reached its peak at 30 ng/ml, after which it started to fall 18 to 30 days before parturition and finally fell to its nadir value one week after parturition. As the correlation coefficient between the urinary PdG and serum P_{4}$ was higher than that corrected by urinary creatinine it can be suggested that the adjustment is not needed. The concentrations of urinary PdG could be maintained stably for 2 days in urine samples stored at room temperature and extended to 8 days when the samples were pretreated by boiling for 30 minutes. In conclusion urinary PdG concentration even without the need for creatinine basis adjustment can be used directly for monitoring the reproductive status of dairy cows.

• Journal of the Society of Disaster Information
• /
• v.10 no.3
• /
• pp.420-430
• /
• 2014

Firefighters performing disaster response activities such as Fire Suppression Rescue First Aid in fire are being exposed in various adverse factors, heat, smoke, toxic gases, emotional stress, biological toxic factors and physical overload by unnatural ergonomic posture required for firefighters. But so far, there is the study for this problem only separately. There is no study about comprehesive analysis of exposed adverse factors in fire-related disaster response activities and countermeasures. The purpose of this study is to contiribute to solving the health problems and prevention of accidents of firefighters by extracting hazardous agents in disaster such as fire and by proposing countermeasures. After analyzing circumstances such as fire-suppression, rescue first aid and life-environment, exposure factors of fire are derived and exposure status is suggested according to physical chemical biological psychological aspects. The countermeasure against the noise of the physical exposure factors are proposed. The countermeasures such as protective equipment and clean room in chemical factors, infection prevention education, vaccination and periodic check system in biological factors, PTSD alleviation booth and mentoring in psychological factors are proposed.

• Korean Journal of Applied Biomechanics
• /
• v.19 no.3
• /
• pp.467-479
• /
• 2009

The purpose of this study was to present the quantitative data which riders can utilize teaching field by comparison analysis of kinematics according to skill level of rider during 2 strides rising trot with the JeJu's-Horse. Participated subjects was consisted of total 10 riders(unskilled: n=5, skilled: n=5). The method of experiment & analysis was based on 3D cinematography. Variables were consisted of temporal, linear & angular kinematics by each event & phase. The skilled assigned more ratio of elapsed time in air than support phase, had the less range of motion in up-down direction and more consistent velocity in lateral & forward direction and performed periodic up-down movement with alignment in vertical direction according to elapsing of phases. The skilled more flexed at elbow and extended backwardly according to elapsing of phases, while more flexed forwardly at hip & knee and plantarflexion at ankle. The skilled postured backward extension but the unskilled do forward flexion. That is, It was considered that the unskilled continued more unstable posture than the skilled during 2 strides in rising trot.