• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.2
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• pp.119-128
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• 2008

In the case of a circular shaft, it is expected that asymmetric loads should apply on the surface rather than symmetric loads due to geographical factors and the non-homogeneity of the jointed rock masses. In this study, discontinuous numerical analysis was carried in order to analyze the characteristics of asymmetric load distribution on the wall of the circular shaft due to anisotropy caused by heterogeneity of rock masses affected by the discontinuities like as a Joint. And it was also analyzed that the effect of the mechanical properties varied with the rock mass rating and horizontal stress with depth had influence in the asymmetric load on the wall of the shaft. In the case of considering the effect of the joint as variable, asymmetric load ratio $(R_p)$, which was defined as the ratio of the load subtracted minimum from maximum to minimum, was below 25% in the hard rock. As regarding the variation of the rock mass rating with depth as variable, the value of $R_p$ was below than 25% in the hard rock, and the value between 30% and 40% in the soft rock. On the other hand, the $R_p$ of fractures rock was between $45{\sim}50%$ which value was much higher than that in better rock mass rating.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.4
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• pp.70-82
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• 2007

Aiming at nature's early restoring needs to select plant species harmonizing with surrounding environment that fits to restoring goal of ultimately aiming at woody plants dominant vegetation that protect and stabilize surface parts of bared slopes. And it is important to make it assimilated with surrounding natural vegetation by differentiating planning of seed mixtures. Natural Ecological Restoring Construction Methods (JSB Method) was developed to increase the effect of landscape change according to seasons not to simple hydro-seeding by reducing rate of foreign grasses while raising rate of wild flower using. It was considered that using wild flowers that bloom on each season solved the problems of slope landscapes that looks artificial and uninteresting. After researching environmental condition of the slopes, JSB Method has shown that, as of wet-type method, soil is relatively soft and the difference of thickness of plant base soil media affects on the difference of soil hardness. In case of soil hardness of 8.8~17mm, there's dangerousness of slope's collapsing, but it has shown that growth of plant was favorable. For the acidity of soil, most of them are in the type of neutralized soil of more than pH 6. And after analyzing the degree of woody plants dominance, it had shown that lower part was occupied with wild flowers and other herbaceous species like China pin, golden phesant mum, pitcher plant, and middle and upper part was occupied with woody plants like silk-tree, sumac forming multi-layer structure. It can be concluded that the restoration objects of the woody plant vegetation on the roadside slopes can be accomplished successfully by Natural Ecological Restoring Construction Method (JSB method).

• Journal of the Korean Geotechnical Society
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• v.30 no.2
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• pp.65-76
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• 2014

For soil improvement, sand mats or sand compaction piles are often constructed on soft marine clays. In such cases, some amounts of sand and clay are inevitably mixed. Sand or gravel often exists in the weathered soils near the slope surface. This research investigates the effect of mixing sand content on consistency limits and shear strength of clays. Firstly, sand was mixed with kaolinite or bentonite at 0, 9, 17, 23, 29, 33, 50% and then liquid and plastic limits were measured. Both plastic and liquid limits decreased as a sand content increased. The water content of clay-sand mixtures with different sand content increased by 10% or 20% step by step and then their undrained shear strength was measured using a portable vane shear device called Torvane. For all cases, undrained shear strength of clay-sand mixtures decreased rapidly until reaching a certain value. Their state changed from undrained to drained state gradually as the sand content increased, which caused their undrained shear strength to decrease. On the other hand, a series of direct shear tests were also conducted on such clay-sand mixtures to investigate the effect of sand content on cohesion and angle of internal friction. It was found from clay-sand mixtures that their cohesion decreased but angle of internal friction increased as the sand content increased.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.4
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• pp.17-35
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• 2016

Earthquake-induced disasters are often more severe in locations with soft soils than firm soils or rocks due to differences in ground motion amplification. On a regional scale, such differences can be estimated by spatially predicting subsurface soil thickness over the entire target area. In general, soil deposits are generally deeper in coastal or riverside areas than in inland regions. In this study, a coastal metropolitan area, Incheon, was selected to assess site effects and provide information on seismic hazards. Spatial prediction of geotechnical layers was performed for the entire study area within the GIS framework. Approximately 7,000 existing borehole drilling data in the Incheon area were gathered and archived into the GIS Database (DB). In addition, surface geotechnical data were acquired from a walkover survey. Based on the built geotechnical DB, spatial zoning maps of site-specific seismic response parameters were created and presented for use in a regional seismic strategy. Site response parameters were performed to determine site coefficients for seismic design over the entire target area and compared with each other. Site classifications and subsequent seismic zoning were assigned based on site coefficients. From this seismic zonation case study in Incheon, we verified that geotechnical GIS-DB can create spatial zoning maps of site-specific seismic response parameters that are useful for seismic hazard mitigation particularly in coastal metropolitan areas.

• The Journal of Korean Physical Therapy
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• v.10 no.1
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• pp.1-6
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• 1998

The purpose of this study was to determine the of effective concentration of procaine iontophoresis for durarion of cutaneous local anesthesia. Forty-five healthy students with an age range of 19 to 34 years$(21\pm2.7)$, were participated in this study. The subjects were randomly assigned into 5 groups. Bach 9 subjects received iontophoresis on the flexor surface of dominant forearm with soft cotton pad $(3.5\times3.5cm)$ soaked in 2ml of $2\%$ (pH 5.28), $4\%$ (pH 5.12), $8\%$ (pH 4,98), $16\%$ (pH 4.72), $32\%$ (pH 4.52) procaine hydrochloride solution at 4mA for 10 minutes (total current 40mA min) using anodal direct current. The study was performed in a randomized, double-blind design, After procaine iontophoresis, the duration of anesthesia were evaluated at five minute intervals on five random locations in the iontophoretically area using a 21-gauge sterile hypodermic needle pressed with 1mm invagination unitl sharp pin-pricking pain sensation returned. The data were analyzed with one-way ANOVA to determine significant differences between groups. Duncan post hoc was performed at level .01. The relationship between anesthetic duration and procaine concentration was assessed with Pearson Product-Moment Correlation Coefficients. ANOVA tests showed significant differences in the anesthetic duration between the concentration of procaine solution (p<.001). Procaine iontophoresis with $4\%$ concentration produced cutaneous Socal anesthesia of significantly longer duration(15.56 min) than iontophoresis with $2\%,\;8\%,\;16\%$, and $32\%$ of procaine GCl(p<.01). Whereas the anesthetic duration had no correlation with concentration of procaine solution (r=-0.41, NS). These results support the $4\%$ procaine solution was an effective concentration of iontophoresis for induced cutaneous local anesthesia.

• Journal of Environmental Health Sciences
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• v.44 no.3
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• pp.238-243
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• 2018

Objectives: The purpose of this study was to determine skin adhesion rate of children's modeling clay for exposure assessment. Methods: Children's modeling clays were classified into 10 categories as PVA clay, PVA soft clay, starch-based clay, foam clay, rubber clay, oil clay, muddy clay, terra clay, paper clay and slime. A total of 26 children's clay goods was selected. Moisture content (%) and hardness of clays were measured. Five adults aged 20 to 25were recruited for experiment. Gravimetric difference of modeling clay was determined after 3 minutes playing time. Skin adhesion rate ($g/min/cm^2$) was estimated bythe amount of skin adhesion per minute (g/min) and each individual's palm surface area ($cm^2$). Results: Twenty four of the 26 children's modeling clay products were adhesive to skins. Two products of foam and rubber clay were not adhered to skin. For the 24 products, the average skin adhesion rate was $5.5{\times}10^{-4}{\pm}4.0{\times}10^{-4}g/min/cm^2$. The highest skin adhesion rate was $1.3{\times}10^{-3}{\pm}4.4{\times}10^{-4}g/min/cm^2$ for paper clay. The lowest skin adhesion rate was $4.6{\times}10^{-5}{\pm}1.1{\times}10^{-4}g/min/cm^2$ for oil clay. The skin adhesion rate was increased with increase of moisture content. Adhesion rates of some clays were varied by person and testing trials. Conclusion: The study determined skin adhesion rate of children's modeling clay. The adhesion rate is useful for exposure and risk assessments and setting safety guideline to protect children's health.

• Archives of Plastic Surgery
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• v.37 no.2
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• pp.137-142
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• 2010

Purpose: Tumor ablation and traumatic intractable ulceration of the plantar surface of the foot results in skin and soft tissue defects of the weight-bearing sole. Simple skin grafting is not sufficient for reconstruction of the weight-bearing areas. Instead, the island medial plantar flap (instep flap) and distally-based island medial plantar flap was used for proper reconstruction of the weight bearing area. However, there are some disadvantages. In particular, an island medial plantar flap has a short pedicle limiting the mobility of the flap and the distally-based island medial plantar flap is based on a very small vessel. We investigated whether good results could be obtained using a reverse island medial plantar flap based on the lateral plantar vessel as a solution to the above limitations. Methods: Three patients with malignant melanoma were cared for in our tertiary hospital. The tumors involved the lateral forefoot, the postero-lateral heel, and the medial forefoot area. We designed and harvested the flap from the medial plantar area, dissected the lateral and medial plantar artery and vena comitans, and clamped and cut the vessel 1 cm proximal to the branch from the posterior tibial artery and vena comitans. The medial plantar nerve fascicles of these flaps anastomosed to the sural nerve, the 5th interdigital nerve, and the 1st interdigital nerve of each lesion. The donor sites were covered with skin grafting. Results: The mean age of the 3 subjects was 64.7 years (range, 57 - 70 years). Histologically, all cases were lentiginous malignant melanomas. The average size of the lesion was $5.3\;cm^2$. The average size of the flap was $33.1\;cm^2$. The flap color and circulation were intact during the early postoperative period. There was no evidence of flap necrosis, hematomas or infection. All patients had a normal gait after the surgery. Sensory return progressively improved. Conclusion: Use of an island medial plantar flap based on the lateral plantar vessel to the variable weight-bearing sole is a simple but useful procedure for the reconstruction of any difficult lesion of the weight-bearing sole.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.5
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• pp.543-547
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• 2015

The cooling process referred to as Tempcore has been applied to produce a high-strength rebar. Excellent rebar with strength and weldability can be manufactured from mild steel without the addition of alloying elements by using the Tempcore process. However, there are limitations to evaluating the effect of various chemical compositions and cooling conditions within a site facility. In this study, we developed an apparatus to simulate the Tempcore process and obtained microstructures with a hardened surface layer, an intermediate region and a soft inner core. The experimental apparatus has been equipped with a cooler set that is the same as the site facility and consists of a pump line that supplies pressure of 12-13 bar and flow rate of up to $50m^3/h$. In accordance with the simulation result of steel grade SD400 that requires more than 400 MPa of yield strength, both the hardened area ratio and the hardness with respect to each cooling depth were found to agree well with the product.

• Journal of Chest Surgery
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• v.12 no.4
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• pp.324-335
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• 1979

During the period of 4 years from August 1975 to August 1979 one hundred and forty seven cases of lung cancer were seen at Paik Foundation Hospital in Seoul, Korea. Among these 147 cases, 104 patients had primary carcinoma of the lung and the remainder was metastatic carcinoma to the lung. Among these 104 primary carcinoma patients, 73 cases were proven histologically as primary carcinoma of the lung. There were three cases of alveolar cell carcinoma [Table 1 ]. This clinical observation is based on those 73 cases including three case reports of the alveolar cell carcinoma. 1. Peak incidence was observed in the 5th decade of life. Male to female ratio was 2 to 1 [Fig. 1]. 2. Pathological classifications were as follows: epidermoid carcinoma, 24 cases [32.9%]; undifferentiated carcinoma, 20 cases [27.4%]; adenocarcinoma, 15 cases [20.5%]; bronchioloalveolar carcinoma [5.5%] and positive cytology, 10 cases [13.7%] [Fig. 2]. 3. Evidence of inoperability was observed in 55 patients [75% of the 73 cases] [Table 3]. 4. Among those 73 cases, operability was evaluated in 18 patients or 25%. One patient refused operation and 17 patients [23.6%] were explored. In 11 [15%] out of 17 patients, thoracotomies were performed. Six cases were pneumonectomies and 5 cases were lobectomies or bilobectomies [Fig. 3]. 5. First case of alveolar cell carcinoma was a 46 year-old housewife complaining of cough and hemoptysis for one year. The plain chest X-ray and bronchogram showed characteristic pictures as Figures 4 and 5. A pneumonectomy was carried out. Histologically, a beautiful alveolar carcinoma consisted of the characteristic tall columnar epithelial cells, which were lining the alveolar spaces as seen in Figures 6, 7, 8, and 20. 6. In the second case of 41 year old male, predominant clinical feature was single, well defined mass in the right lower lobe [Fig. 10 and 11] on chest X-ray. Bilobectomized specimen showed fragile, soft and hard tissue containing mucoid secretions and focal yellowish necrosis with pigmentation on cut surface [Fig. 12]. Slides showed tumor cells lined up along the alveolar septa with papillary projections [Fig. 13 and 14]. 7. Third case of alveolar cell carcinoma was a 50-year-old housewife with hemoptysis. An outstanding clinical picture was a round to lobulated mass in the right upper lobe [Fig. 16]. She is living now, 2 years and 1 month post-operatively, but has arrived at terminal stage with military nodular disseminations to the contralateral lung [Fig. 19].

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.196-199
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• 2003

This experiment was conducted to evaluate the differences in physicochemical properties of soil, grain yield and milling recovery ratio and grain appearance of rice grown in long-term no-till and ordinary till systems. The paddy in no-till rice system was unploughed but straw-mulched for 15 years from 1988 to 2002 at the Experimental Paddy of Gyeongnam Agricultural Research and Extension Services, while the paddy in ordinary till system was ploughed and puddled every crop year, A 5cm organic layer was formed in 11-year no-till rice system, in which exchangeable cation and phosphate were accumulated. In no-till paddy organic matter, bulk density and solid phase of surface soil significantly increased, while pH, exchangeable cation, phosphate, liquid and gaseous phase decreased. Tillage made the very top soil soft, but made deep soil below 5cm significantly hard. In the 1st year of no-till, topsoil showed hard, but in the process of the time in no-till system, the top- and sub-soil showed softer, Yield and yield components of rice showed no differences between till- and no-till rice systems. Milling recovery ratio and grain appearance were not significantly different between no-till and till-rice systems.