• Journal of Korean Society of Forest Science
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• v.62 no.1
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• pp.82-86
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• 1983

Cone and seed development after self-pollination in 14-year-old Pinus rigida Mill. was investigated in an $F_1$-hybrid seed orchard that consists of Pinus rigida Mill. and Pinus taeda L. in alternative rows. On an average, 83.8% of the self-pollinated receptive female strobili developed into cones. This value appears to be normal compared to cone development after open-pollination in other pine species such as in Pinus sylvestris L. However, there was a great variation in filled seed development after self-pollination among the investigated individual trees (Table 1-1). The 34.5%, a ratio of filled seeds after self-pollination was significantly lower than 91.7%, that by the open-pollination. Some of the investigated trees developed 70.0%-83.5% of filled seeds after self-pollination. Thus, those are not desirable as trees for seed parent in establishing $F_1$-hybrid seed orchards in future. A further study on the rate of filled seed development by various pollination systems consisting of self-pollination, self-and cross-pollination with intraspecific, mixed (tree's own and foreign pollens) pollens and cross-pollination with interspecific, mixed pollens of the two parental tree species is necessary to determine the quality of seed parent trees in establishing $F_1$-hybrid seed orchards.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.6
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• pp.482-488
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• 2011

Seadike is a coastal structure constructed in the rear region of the foreshore to maximize its usability by preventing direct effect of wave. The expected construction field is determined under the design wave and tidal condition where minor wave overtopping is anticipated. Thus, the location of seadike is generally fixed at the highest site of the surrounding area with seadike crest height controlling the permissible range of wave overtopping volume. But a lot of times, frontal sand beach of the seadike continuously deforms due to incident waves, resulting failure in maintaining its initial slope. The erosion and deposition of the seadike front cause changes in the crest height and volume of wave overtopping and decrease in the setting depth of the seadike, which endangers seadike region as a result. In this study, the relation of local scouring and setting depth of the seadike front in the run-up region is examined by using 2D hydraulic model tests and numerical simulations by modified SBEACH model. As a result, the study learned that if appropriate boundary condition is applied to the modified SBEACH model, it is possible to create practical estimations on the local scouring at the seadike foot when erosive waves flow into the region.

• Journal of the Korean Geographical Society
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• v.46 no.4
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• pp.396-412
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• 2011

Multi-proxy analysis was used to produce a high-resolution paleoclimatic record from a thick section of the Holocene alluvial fan deposit in Gatap-ri, Buyeo. According to ${\delta}^{13}C$ analyses, five minor climate fluctuations can be determined. From the stage I to stage VI, climate changes are as follows: cool-dry, warm-humid, cool-dry, warm humid, drier than stage IV, and finally more humid environment than stage V. According to magnetic susceptibility records, four different stages can be identified, among which stage ii shows the highest susceptibility. Stage-i deposit is derived from sediments of back marsh-type wetland. Stage-ii and stage-iii deposits, however, show higher magnetic susceptibility because magnetite-enriched soil from weathered upland was transported to the area to form an alluvial fan deposits. Stage-iv deposit is comparable to the modern plow horizon.

• Economic and Environmental Geology
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• v.37 no.5
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• pp.499-508
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• 2004

Changwon City first constructed riverbank filtration plants in Book-Myeon and Daesan-Myeon in Korea in the year 2001. This study evaluated hydrogeological characteristics and groundwater flow simulation between the Nakdong River and the fluvial aquifers adjacent to the river in Book-Myeon, Changwon City. The groundwater simulation calculated the influx rate from the Nakdong River and the fluvial aquifers to pumping wells through the riverbank filtration system. The groundwater flow model utilized drilling, grain size analysis, pumping test, groundwater level measurements, river water discharge and rainfall data. Hydraulic heads calculated by the steady-state model closely matched measured heads in pumping and observation wells. According to the transient flow model, using a total pumping amount of 14,000 $m^3$/day, the flux into the pumping wells from the Nakdong River accounts for 8,390 $m^3$/day (60%), 590 $m^3$/day (4%) is from the aquifer in the rectilinea. direction to the Nakdong River, and 5,020 $m^3$/day (36%) is from the aquifer in the parallel direction to the Nakdong River. The particle tracking analysis shows that a particle from the Nakdong River moves toward the pumping wells at a rate of about 1.85 m/day and a particle from the aquifer moves toward the pumping wells at a rate of about 0.75 m/day. This study contributes to surface water/groundwater management modeling, and helps in understanding, how seasonal change affects pumping rates, water quality, and natural recharge.

• Journal of the Korean Society of Radiology
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• v.14 no.4
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• pp.425-431
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• 2020

When a radiation generating device is installed in an export container due to COVID-19, the purpose of this study was to measure the space dose in the radiation room and to study the effectiveness of the shielding wall in the laboratory. Air dose measurement method was set behind the X-ray tube, 50 cm, 100 cm, 200 cm, and measured 12 locations. The dose values before and after the use of the movable radiation shielding wall were compared by measuring 3 locations behind the X-ray tube using the movable radiation shielding wall. The measured values were 50 cm on the left behind the X-ray tube: 1.446 μSv, behind the X-ray tube: 0.545 μSv, and 50 cm on the right behind the X-ray tube: 1.466 μSv. Measurements behind the radiation barrier were 0.190 μSv, 0.204 μSv, and 0.191 μSv. As a result of performing the corresponding sample t test of the average value according to the use of movable barrier walls, p <0.001 was found. As a result of the actual measurement, the medical exposure of the examiner due to the shielding wall in the laboratory decreased to 82.3%. In order to reduce occupational exposure in screening radiological laboratories, it is recommended that sufficient separation from radiation sources and the use of shielding walls are recommended.

• Journal of the Korean association of regional geographers
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• v.2 no.1
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• pp.39-49
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• 1996

There is a limestone basin surrounded by the mountains consisted of Paleozoic sedimentary and metamorphic rocks in the Masung, Munkyung city, Kyungsangpook do. The purpose of this paper is to elucidate the geomorphic processes of the gentle hillslopes in the marginal piedmont of Masung basin. To do so, I analyzed deposits over hillslopes and the relation ship between the distance from the divide and the height(above sea level) at the longitudinal profile of the hillslope, and considered interrelation between the distributions of the gentle hillslopes(less than 230m) and lithology. Geomorphic processes of Masung basin are as follow: (1) The depth of deposits over hillslope increases toward downstream of the hillslope. Most gravels within deposits, whose lithology is limestone, are those eroded at the boundary(overthrust fault zone) between the back-mountain and the hillslope. Deposits at the outward margin of hillslope is well sorted. and moderately imbricated. (2) Hillslope at the margin of the basin(160-230m asl) is formed by the action of 'the flow with channel'. At the boundary between the soft rock(limestone; basin floor) and hard rock(sedimentary and metamorphic rock; back-mountain), the relatively weak limestone is eroded to fresh bedrock by the subsequent action of the overland flow, and therefore discontinuity in slope appeared. (3) After hills lopes were formed, sediments(boulders and fine material) produced during dissection in back-mountain buried deposits over hillslope. In conclusion, geomorphic processes of Masung basin is 'differential erosion due to differentiation of lithological hardness' having suggested as geomorphic processes of granitic basin. However it is not 'removal of weathering material due to sheetflow' but 'erosion due to the overland flow with channel'.

• Journal of Korea Port Economic Association
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• v.28 no.1
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• pp.123-142
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• 2012

The purpose of this paper is to suggest a plan on succeeding together-Busan New Port & BJFEZ(that is, port hinterland development). This study deals with the terms of three connection growth factors which are a firm's subjective factors, a industrial environment factors, and a governmental policy factors. According to analysis results of the factors, a firm's subjective factors(4.11 score) are scored the most ones of connection growth factors of Busan New Port & BJFEZ, to be compared with a governmental policy factors(4.01 score). with a industrial environment factors(3.92 score). Therefore, first of all, Busan New Port & BJFEZ have to promote connection growth through as follows, a firm's subjective factors : (1) to procure competitiveness through establishment of connection growth model, (2) to promote concentrated marketing strategy & market response ability, (3) speedy meeting to customer's needs, (4) to procure reliability of Busan New Port & BJFEZ. And, the next, Busan New Port & BJFEZ have to promote connection growth through considering a governmental policy factors, a industrial environment factors.

• Korean Security Journal
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• no.15
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• pp.89-105
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• 2008

The aim of this study is to examine the primary causes of security guard's stress by conducting a survey of 50 guards engaging in security companies in Seoul and Gyeonggido. The following results are attained by an inductive content analysis of conviction interview data through in-depth interview of qualitative study method. 1. Factors of stress related to personal problems. The stress by personal problems is resulted from two factors. One is the physical strength inferiority, which leads to negative thoughts, dismay, mental conflict and tension. The other is complex about not-specializing security, which causes discord with his/her supervisor or co-workers and a feeling of uneasiness. 2. Factors of stress related to human relationship. The stress due to human relations is constantly resulted from discord with his/her supervisor and inclined to be accumulated. The mental conflict is elated in feeling that the manager's instructions are not right. So this factor makes them want change of occupation. Also working conditions are different from those of their friends, which causes them not to spend a lot of time with their friends. 3. Factors of stress related to domestic life It appears that most security guards are under stress due to their spouses' discontent with a small number of wages. Also it is reported that male guards are under stress in case of unhappy conjugal relations. And security guard's life is restricted much more than that of workers in a general occupation because of standing ready for mobilization and 24-hour service. So some of male guards experienced an early symptoms of a morbid suspicion about their wife's chastity and are suffering from insomnia as an occupational disease.

• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.267-276
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• 2015

This study suggests a macroscopic method of evaluating forest recreation function based on physical characteristics of forests. The method was verified by a correlation between forest recreation function in popular top 45 mountains and popularity among them, with using data-mountain area, height, distance between mountain and cities, population around mountain, and size of public service. According to analysis of the forest recreation function, it is shown that top 8 mountains, including Jirisan and Seoraksan, provide over 64% of total recreation function, while they serve the function relatively lower than mountains near mega cities-Bukhansan in Seoul-do, in terms of the function per unit area ($km^2$). It is because, in a case of national and provincial mountains, the size of mountain is likely a critical factor for determining recreation function and the distance influences on it relatively lower. These findings implicate that a large size of forests bring the recreation function to visitors on nationwide level, whileas forests in suburban provide intensively it to near population to near population.

• Korean journal of applied entomology
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• v.31 no.4
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• pp.396-415
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• 1992

To investigate identification of species distribution state, population density of plant parasitic nematodes and damaged state by parasitism of nematodes with soil samples taken from major cultivating area of medicinal herbs in Kyungbuk districts are summarized as follow; total species belonging to genera in families were identified from 43 different medicinal herbs. The dominant nematode species on medicinal herbs was Meloidogyne hapla by 55.6% of field infection. Damaged state by parasitizm of Root-knot nematode, M. hapla, M. incognita are severed 15 medical plant except P. japonica, infected field were in 54.5~88.0%, and highered in population densities of 2nd larvae, Gall, Egg sac. Percentage of yield-decrease were 57.8% in A. gigas, 49.1% in P.japonica. Lighten effect of M. spp. by cropping system were lowered in population density in Rice+Paeony than Paeony+Paeony in paddy field, and also lowered in Sesame+Paeony or one year fallowing after harvest Paeony than Red pepper+Pseony, Paeony+Paeony in upland field.