• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.29 no.1A
• /
• pp.9-18
• /
• 2009

This paper introduces the application of DE (Differential Evolutionary) method for the estimation of tensile force of the externally prestressed tendon. The proposed technique, a SI (System Identification) method using the DE algorithm, can make global solution search possible as opposed to classical gradient-based optimization techniques. The numerical tests show that the proposed technique employing DE algorithm is a useful method which can detect the effective nominal diameters as well as estimate the exact tensile forces of the externally prestressed tendon with an estimation error less than 1% although there is no a priori information about the identification variables. In addition, the validity of the proposed technique is experimentally proved using a scale-down model test considering the serviceability state condition without and with the loss of the prestressed force. The test results prove that the technique is a feasible and effective method that can not only estimate the exact tensile forces and detect the effective nominal diameters but also inspect the damping properties of test model irrespective of the loss of the prestressed force. The 2% error of the estimated effective nominal diameter is due to the difference between the real tendon diameter with a wired section and the FE model diameter with a full-section. Finally, The accuracy and superiority of the proposed technique using the DE algorithm are verified through the comparative study with the existing theories.

• Journal of the Economic Geographical Society of Korea
• /
• v.26 no.4
• /
• pp.359-374
• /
• 2023

The main purpose of this paper is to explore the relationship between the transformation of Chinese regional development policy and trends in spatial inequality in mainland China. More specifically, it has attempted to identify the effects of Chinese regional development policies on regional economic inequality by investigating the coefficient of variation and Gini coefficient with GRDP in the province level. Regional inequality in China had increased from 1979 economic reform, but has eased since the 10th Five Year Plan(2001~2005) due to large-scale state investments in the western, central and northeastern regions. However, the analysis is likely to be resulted from the national level. Trends in regional inequality are differentiated in accordance with the eastern, central, northeastern and western regions. For example, regional inequality in the central region has increased, whereas other three regions has decreased since the 10th Five Year Plan. It has played a role in cutting down regional inequality in the national level. In particular, the central region has kept inequality since the 12th Five Year Guideline. It has led to the convergence of the regional economies in the national level. It has stemmed from some limits to greater regional policies in the Central region enforced in the 11th Five Year Guideline(2005~2010).

• Korean Journal of Remote Sensing
• /
• v.40 no.3
• /
• pp.275-284
• /
• 2024

Monitoring crop growth changes and water content is crucial in the agricultural sector. This study utilized drones equipped with Short Wavelength Infrared (SWIR) sensors, sensitive to moisture changes, to observe soybeans' growth and water content variations. We confirmed that as soybeans grow more vigorously, their water content increases and differences in irrigation levels lead to decreases in vegetation and moisture indices. This suggests that waterlogging slows down soybean growth and reduces water content, highlighting the importance of detailed monitoring of vegetation and moisture indices at different growth stages to enhance crop productivity and minimize damage from waterlogging. Such monitoring could also preemptively detect and prevent the adverse effects of moisture changes, such as droughts, on crop growth. By demonstrating the potential for early diagnosis of moisture stress using drone-based SWIR sensors, this research suggests improvements in the efficiency of large-scale crop management and increases in yield, contributing to agricultural production.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.15 no.3
• /
• pp.171-177
• /
• 2013

The purpose of this study is to find a scheme to scale down the KMA (Korea Meteorological Administration) digital precipitation maps to the grid cell resolution comparable to the rural landscape scale in Korea. As a result, we suggest two steps procedure called RATER (Radar Assisted Topography and Elevation Revision) based on both radar echo data and a mountain precipitation model. In this scheme, the radar reflection intensity at the constant altitude of 1.5 km is applied first to the KMA local analysis and prediction system (KLAPS) 5 km grid cell to obtain 1 km resolution. For the second step the elevation and topography effect on the basis of 270 m digital elevation model (DEM) which represented by the Parameter-elevation Regressions on Independent Slopes Model (PRISM) is applied to the 1 km resolution data to produce the 270 m precipitation map. An experimental watershed with about $50km^2$ catchment area was selected for evaluating this scheme and automated rain gauges were deployed to 13 locations with the various elevations and slope aspects. 19 cases with 1 mm or more precipitation per day were collected from January to May in 2013 and the corresponding KLAPS daily precipitation data were treated with the second step procedure. For the first step, the 24-hour integrated radar echo data were applied to the KLAPS daily precipitation to produce the 1 km resolution data across the watershed. Estimated precipitation at each 1 km grid cell was then regarded as the real world precipitation observed at the center location of the grid cell in order to derive the elevation regressions in the PRISM step. We produced the digital precipitation maps for all the 19 cases by using RATER and extracted the grid cell values corresponding to 13 points from the maps to compare with the observed data. For the cases of 10 mm or more observed precipitation, significant improvement was found in the estimated precipitation at all 13 sites with RATER, compared with the untreated KLAPS 5 km data. Especially, reduction in RMSE was 35% on 30 mm or more observed precipitation.

• The Journal of Industrial Distribution & Business
• /
• v.2 no.2
• /
• pp.39-45
• /
• 2011

The Korean distribution industry is gearing up for an endless competition. Greeting low growth era, less competitive parties will be challanged seriously for their survival. But for large discount stores, they have shown steady annual growth for years. However, because of the saturation for numbers of stores, the difficulty of gaining new sites, and the changes in the consumer's consumption behavior caused by the recession, now they are seeking for a new customers-based business formats. Accordingly, a large corporate comopanies made supermarkets which are belonged to affiliated companies of large corporate comopanies. They based on the strong buying power, focused on SSM(Super Super Market) ave been aggressively develop nationwide multi-stores. The point is that these stores are threatening at small and medium-sized, community-based private supermarkets. Private supermarkets and retailers, who are using existing old operation systems and their dilapidated facilities, are losing a competitive edge in business. Recent the social effects of large series of corporate supermarkets for traditional markets has been very controversial, and commercial media, academia, and industry associated with it have been held many seminars and public hearings. This may slow down the speed in accordance with the regulations, but will not be the crucial alternative. The reason for this recent surge of enterprise-class SSM up, one of the reasons is a stagnation in their offline discount mart, so they are finding new growth areas. Already in the form of large supermarkets across the country got most of the geographical centre point and is saturated with stages. Targeting small businesses that do not cover discount Mart, in order to expand business in the form of SSM is urgent. By contrast, private supermarkets are going to lose their competitiveness. The vulnerability of individual supermarkets, one of the vulnerabilities is price which economies of scale can not be realized so they are purchasing a small amount of products and difficult to get a quantity discount. The lack of organization and collaboration, and education which is not practical, caused the absencer of service-oriented situations. As a first solution, making specialty shops which are handling agricultures, fruits and vegetables and manufactured goods is recommended. Second, private supermarkets franchisees join the organization for the organization and collaboration is recomaned. It can be meet the scale of economy and can be formed a alternative business formats to a government. Third, the education is needed as a good service will get consumer's awareness. In addition, a psychological stores operating is also one way to stimulate consumer sentiment as SSM can't operate. Japan already has a better conditions of their lives through small chain expression. This study includes the vulnerabilities of private supermarkets, and suggests a competitiveness reinforcement strategies.

• Korean Journal of Soil Science and Fertilizer
• /
• v.11 no.4
• /
• pp.213-233
• /
• 1979

It is generally agreed that the country's population will grow up to the level of 52 million by the year of 2000 and that due the active growth of industry, urbanization and road constructions, sizable portion of existing arable lands will be utilized for other purposes than agriculture in near future. From 1966 to 1977, it was estimated that, the average annual conversion of arable lands to other uses, was 12,909 ha. If this trend persists, it is predicted that from 1978 to 1991 when the 6th Five Years Economic Development Plan will terminate, approximately 181,000 ha of arable lands will be converted for other uses again. On the other hand, it is certain that the increased population (39 million in 1981, 45 million in 1991, 52 million in 2001) and the changes in food pattern along with the enhancement of living standards will bring about the phenomenal increase in demands for not only the staple food but also the livestock products such as meat, milk and eggs, vegetables and fruits. These future increased demands for various foods, naturally mean the increased needs for the expansion of arable lands at the same time. It is predicted that, if more activities than present scale are not taken for the expansion of arable lands, the national food self sufficiency level will drop from 79% in 1977 down to 62% in 1991. To meet the increased food demands in future, there are several ways and means. These will include the increased land use intensity, elevation of unit area yield levels, minimization of conversion of arable lands to other uses and expansion of arable lands through the reclamations of idle hillside lands and tidal lands. Among these, the expansion of arable lands through reclamations of idle hillside lands and tidal lands are more positive measures to cope with the increased production of foods in future. The reclamation of hillside lands demands more attention because it needs more advanced technologies in agronomical and engineering aspects, larger scale fundings and integrated socioeconomic considerations. In agromical aspects, the thechniques for early improvement of chemical and physical properties of soils, proper soil conservation measures and rational cropping systems are of particular importance. As to the financial supports to encourage the farmings in hillside land, much bold fund inputs are essential for the construction of roads, installation of irrigation and drainage facilities, soil conservation mechanisms, which will ensure the stabilized farming with reasonable incomes in the newly reclaimed lands.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.4 no.3_4
• /
• pp.79-91
• /
• 1971

A boat seine has been used as a major fishing gear for catching anchovy (Engraulis japonica) in the southern coastal waters of Korea since 1920s. The original seine was operated by two rowing boats as the haul seine. The rowing boats were, in recent, replaced by powered boats. The net size was enlarged by more than three times the original nit as they began to by operated in the deeper waters of approximately sixty meters. However, there are many problems in the efficiency of the fishing gear to be improved. The authors studied on the hydrodynamic resistance and performance of the boat seine net of the 1/10 scale model in tow. The results are summaried as follows. 1. The hydrodynamic resistance converted from model experiment into the full scale is: $$R_1=30,000\;v^{1.2}\;(0.2{\leqq}v{\leqq}1.0)$$ $$R_2=16,000\;v^2\;(0.2{\leqq}v{\leqq}0.6)$$ where $R_1$ and $R_2$ denote the resistance of whole gear and of bag net in kg respectively, and v the speed of flow in m/sec. 2. In the extension wing, approximately seventy percent of the length of the ground rope from the towing end to the inside-wing slopes down from sea level toward the sea bottom, while the thirty percent of the inside of it remains parallel with th: 5:a level. The performance is regarded to b: inefficient for driving fish shoal into the inside-wing, especially for the shoal diving suddenly. 3. At the towing speed higher than 0.2 m/sec, the trailing edge of the inside-wing is blown backward beyond the seaming line connecting the inside-wing and the mouth of the bag net. It is regarded as an unreasonable performance to drive the fish shoal smoothly into the bag net. 4. At the towing speed higher than 0.2 m/sec, the posterior end of the lower bosom is lifted up above the level of the ground rope of the inside-wing. It is considered that the fish shoal diving suddenly can escape through the discrepancy between the lower bosom and the sea bottom, even if the ground rope of the inside-wing sweeps the sea bottom. 5. The angle of inclination of the upper bosom is estimated as $35\~40^{\circ}$. It seems that the inclination is too steep to drive smoothly the fish shoal diving toward the sea bottom into the bag net. 6. In structure, circumference of the posterior section of the bag net is wider by 1.3 times that of the anterior section. Actually in towing at a speed higher than 0.2m/sec, however, the circumference of the posterior section becomes smaller than that of the anterior section. It is recommended to be designed in a long cylindrical form.

• Journal of Environmental Health Sciences
• /
• v.10 no.2
• /
• pp.9-40
• /
• 1984

This thesis purports to overview the diverse administrative and organizational factors and plannings developed by the government organizations, municipal or otherwise, to tackle the Han River water pollution issues in the past years. This thesis also looks into the ever-worsening Han River water pollution problems, in particular, in terms of the various government plans ostensibly designed to reduce the pollution level but with little success. Also dealt with are the efficiencies with which the laws and decrees on water pollution the administrative organizations put to use in the prosecution of the diverse antiwater pollution projects involving the Han River basin. From the early 1960's up to the 1970's the government had concentrated on the growth-oriented economic policy with the result that little attention had been paid to the water pollution and other environmental issues that are bound to arise from the massive economic growth. Belatedly, the five-year Hah River Development Project was initiated in 1982 with emphasis on reducing the water pollution level at Hah River to the minimum. The following are the gists of the thesis and recommendations for the future antiwater pollution plans by the administrative organizations: 1. Documents to date indicate that the irrigation projects along the Han River area had been the main focus of attention during the Yi Dynasty and under the Japanese rule of the country. 2. Despite that the water pollution issue became the subject of many debates among the academic and research institutions in the 1960's and in the 1970's, the administrative organizations in charge of the Han River water quality control failed to come up with a concrete plan for the river's water quality control. 3. Nevertheless, the water pollution of the Han River area in fact began in the 1950's, with the unprecedented concentration into Seoul of population and the industrial facilities on a larger scale, in particular, enforced by the government's strong growthoriented policy in its Economic Development plans in the 1960's. 4. Starting in the 1960's, the Han River water pollution level dramatically increased, but the government was reluctant to promulgate or put into effect strong measures to curb the many factors contributing to the river water pollution, thus worsening the environmental issues along the Han River basin. 5. The environmental protection law and other laws and decrees relating to the antiwater and air pollution issues that were subsequently put into effect underwent so many changes that efficient anti-water pollution policies could not be effected for the Han River basin. The frequent organizational reshuffle within the administrative units concerned with environmental problems has resulted in the undue waste in personnel management and finance. 6. The administration on the environmental protection could not be efficiently carried out due to the organizational overlapping. Under the existing law, frequent organizational frictions and inefficiency are bound to occur among the central government offices themselves, as well as between the central government and the Seoul city administration, and among the city's administrative offices over the conservation of the Han River basin and over the river's anti-water pollution issue. 7. In the planning and prosecution of the Han River project, political influences from the president down to the lower-level politicious appear to have been involved. These political influences in the past had certainly had negative influence on the project, nevertheless, it appears that in the recent years, these political influences are not all that negative in view of the fact that they serve as a positive contributing factor in developing a better water quality control project along the Han River basin. The following are a few recommendations based on the data from the thesis: First, officials in charge of the Han River water quality control should pay attention to a careful screening of the opinions and recommendations from the academic circles and from the public should be made so that the government could better grasp the core issues in the environmental problems that require preventive and other necessary measures. Second, vigorous redistribution policies of population and industrial facilities away from the Seoul area should be pursued. Third, the government should refrain from revising or revamping too frequently the laws and decrees on the anti-water pollution, which is feared to cause undue inconveniences in the environmental administration. Fourth, a large-scale streamlining should be made to the existing administrative organization in an effort to do away with the inter- and intra-organizational friction. It is recommended that a secretariat for the Hah River basis conservation be established. Fifth, High-level administrative officials, with a thorough knowledge and vision on the Han River water quality control, should be prepared to better deal with the budgeting and personnel management for the Han River water pollution control not only at the control government, but also at the Seoul city municipal government levels. Environmental issues should be kept distinct from political issues. Environmental issues should not serve as a window-dressing for sheer political purposes. Sixth, the Hah River proiect should also include, along with the main Han River basin, those areas covering North Han River, South Han River, and the tributaries to the main river basin. The 'Han River Basin Water Quality Control Board' should be established immediately as a means of strengthening the current Han River basin water quality control policy. Seventh, in drawing up the Han River proiect, the administrative officials should be aware that Han River basin is a life line for those people in the region, providing them with not only a sheer physical space, but with a psychological living space for their everyday life.

• The Korean Journal of Petroleum Geology
• /
• v.10 no.1_2 s.11
• /
• pp.23-33
• /
• 2004

The Lago Sofia conglomerate in southern Chile is a lenticular unit encased within mudstone-dominated, deep-sea successions (Cerro Toro Formation, upper Cretaceous), extending from north to south for more than $120{\cal}km$. The Lago Sofia conglomerate is a unique example of long, gravelly deep-sea channels, which are rare in the modern environments. In the northern part (areas of Lago Pehoe and Laguna Goic), the conglomerate unit consists of 3-5 conglomerate bodies intervened by mudstone sequences. Paleocurrent data from these bodies indicate sediment transport to the east, south, and southeart. The conglomerate bodies in the northern Part are interpreted as the tributary channels that drained down the Paleoslope and converged to form N-S-trending trunk channels. In the southern part (Lago Sofia section), the conglomerate unit comprises a thick (> 300 m) conglomerate body, which probably formed in axial trunk channels of the N-5-trending foredeep trough. The well-exposed Lago Sofia section allowed for detailed investigation of sedimentary facies and large-scale architecture of the deepsea channel conglomerate. The conglomerate in Lago Sofia section comprises stratified conglomerate, massive-to-graded conglomerate, and diamictite, which represent bedload deposition under turbidity currents, deposition by high-density turbidity currents, and muddy debris flows, respectively. Paleocurrent data suggest that the debris flows originated from the failure of nearby channel banks or slopes flanking the channel system, whereas the turbidity currents flowed parallel to the orientation of the overall channel system. Architectural elements produced by turbidity currents represent vertical stacking of gravel sheets, lateral accretion of gravel bars, migration of gravel dunes, and filling of channel thalwegs and scoured hollows, similar to those in terrestrial gravel-bed braided rivers. Observations of large-scale stratal pattern reveal that the channel bodies are offset stacked toward the east, suggestive of an eastward migration of the axial trunk channel. The eastward channel migration is probably due to tectonic tilting related to the uplift of the Andean protocordillera just west of the Lago Sofia deep-sea channel system.

• Korean Journal of Heritage: History & Science
• /
• v.47 no.1
• /
• pp.66-81
• /
• 2014

Burnt down during the Imjin War(壬辰倭亂) of 1592, Gyeongbokgung Palace(景福宮) remained in ruins until 1865, when in the second year of King Gojong's(高宗) reign, reconstruction work began. At the time, a royal protocol(uigwe, 儀軌) for the reconstruction was not produced. Instead, the Gyeongbokgung Palace Construction Diary(Gyeongbokgung yeonggeon ilgi, 景福宮營建日記) records the reconstruction process from June to September of 1865. The contents of this diary reveal that the stone used in the construction was obtained from Ganghwa(江華), the Yeongpung field(映楓亭) just beyond Dongdaemun, and Samcheongdong(三淸洞), among other sites. In addition, selected stone remaining from the original Gyeongbokgung Palace site - such as that from the palace astronomical observatory(ganuidae, 簡儀臺) - as reused, while a number of buildings and stonework from Gyeonghuigung Palace(慶熙宮) were moved to Gyeongbokgung Palace. As a result, a number of $17^{th}$ and $18^{th}$ century stonework are currently located at Gyeongbokgung Palace. The Gyeongbokgung Palace Construction Diary contains a record indicating that the bronze dragon(靑銅龍) excavated from the lotus pond at the palace's Gyeonghoeru Pavilion(慶會樓) was created by special technician byeolganyeok(別看役) Kim Jae-su(金在洙) in 1865 for the symbolic purpose of protecting the palace from fire. The diary also reveals that among Kim Jae-su and the other special technicians(byeolganyeok) tasked with the installation and oversight of the palace stonework was Lee Se-ok(李世玉) - aid to have created the haechi statue at Gwanghwamun Gate. This indicates that there were men of court painter(hwawon, 畵員) background among the construction special technicians(byeolganyeok). Moreover, the diary records the names of the stoneworkers(seokjang, 石匠) who worked under these special technicians to actually carve the stonework. These included Jang Seong-bok(張聖福), who participated in the creation of the Geunjeongjeon Hall(勤政殿); and Kim Jin-myeong(金振明), who took part in the construction of Gwanghwamun Gate(光化門). Based on these results, it is possible to identify a number of special iconographic features of the scale-covered animal form(insuhyeong, 鱗獸形) auspicious animal statues at Gyeongbokgung Palace. These include a protruding mouth and large nose, formalized ears, and a mane along the back. Comparing these iconographic features with those found in the stonework of Joseon tombs makes it clear that these palace statues were created in the latter half of the $19^{th}$ century - the period corresponding to Gojong's palace reconstruction. This study was able to confirm that this iconography was taken up by the Gyeongbokgung Palace construction special technicians(byeolganyeok) and stoneworkers(seokjang) as they worked on tomb stonework earlier in their careers.