• Journal of Biosystems Engineering
• /
• v.34 no.6
• /
• pp.397-403
• /
• 2009

This study was carried out to investigate the present status of subsoil compaction, and subsoil compaction management in orchard as a basic study for developing a self-propelled explosive subsoiler. Subsoil compaction was evaluated using the soil penetration resistance. Soil cone index was measured using the DIK 5520 type cone penetrometer in several fruit farms such as apple, pear, peach and grapes during growing seasons of these fruit in Jecheon, Gamgok, Choongju, Cheonan and Hwasung areas. Most of the subsoil managing machinery were either explosive type or digging type attached to the tractor or power tiller and turning radius of this machine was more than 3-5 m. Many of the farmers wanted to use the subsoiler which can put lime into soil and rupture soil at the same time. For most of the orchard fields, soil penetration resistance in vehicle traffic area was increased quickly and reached about 1.0 MPa in 5 cm soil depth. As the soil depth increased to 15-20 cm, cone penetration resistance reached about 2.0-2.5 MPa which restricted root growth seriously. Thus it was concluded that one of the main reason for increasing the soil compaction in orchard fields is agricultural vehicle traffic. In the vicinity of fruit trees, compaction is not so serious compared to that of the vehicle traffic area, but as the soil depth increased to 20-25 cm, in most of the orchard fields soil penetration resistance reached about 2.0-2.5 MPa which is the root growth-limiting value. Considering the rooting depth of fruit trees which ranged 30-60 cm for apple, pear and peach, and 20-30 cm for grape, it is necessary to loosen the subosoil and improve the subsoil conditions using subsoiler.

• Journal of the Korean Ceramic Society
• /
• v.23 no.1
• /
• pp.51-59
• /
• 1986

It was the first time the MgO-C brick was developed for the lining materials in the hot spots in electric are furnace in 1972. MgO-C brick is high registant to thermal and structural spalling. Futhermore for the reason that carbon is hard to react with slag and MgO is high fireproof MgO-C brick shows a high corrosion registance to slag attack compared with conventional basic refractories. Owing to their excellent properties the use of MgO-C refractories are being developed widely in the field of shaped refractories and even in that of monolithic refractories. In this paper the oxidation of carbon the infiltration of slag into the brick texture and effects of additions were investigated. The results obtained were as follows : 1) The use of fused MgO-clinker and high purity carbon as raw materials increased the corosion registance and hot modulus of rupture of MgO-C brick. 2) As the oxidation reaction of the carbon proceeded the slag infiltrated into the brick texture. And then the slag components reacted with the MgO grains and formed low melting point compounds particulary CaO.MgO.$SiO_2$ and 3CaO.MgO.$2SiO_2$ that resulted in the wear of the brick. 3) It is recongnized the Al, Si, $B_3C$ effects on the oxidation registant properties of MgO-C brick by contribu-ting to the decrease of permeability according to the formation of $Al_4C_3$, SiC, $B_2O_3$ and the decrease of open pores relating to the formation of MgO.Al2O3, $SiO_2$, 3MgO.$B_2O_3$ at the decarbonized layer.

• Journal of The Korean Society of Integrative Medicine
• /
• v.2 no.1
• /
• pp.63-76
• /
• 2014

Purpose : The purpose of this study was to ascertain the effects of scapular stabilization exercise before rotator cuff surgery on pain and range of motion of middle-aged women. Method : 20 subjects who agreed on this experiment and were diagnosed with rotator cuff rupture participated in this study. Experimental groups were treated while 40 minutes a day, 5 times per week, for 2 weeks before surgery. The effects of scapular stabilization exercise were evaluated on VAS and range of motion. Collected data were analyzed with SPSS for windows ver. 20.0 program. One-way repeated ANOVA was used to examine a significance of each variable by time. Two-way repeated ANOVA was applied to examine a significance of the experimental group against the control group. In all statistical tests, the significance level was set by ${\alpha}=.05$. Result : The results of this study are as follows: 1) In both control and experimental groups, VASs were decreased significantly according to intervention period. There was no significant difference between VASs of two groups. 2) In both control and experimental groups, ROMs of shoulder, flexion, abduction and external rotation were increased significantly according to intervention period. In these three flexibility measurement variables, there were significant differences between ROMs of two groups. Conclusion : In view of all the results in this study, scapular stabilization exercise on before rotator cuff surgery proved to be effective in improving their pain, range of motion after surgery. It will be sufficient data to perform with their own exercise program.

• Journal of Korean Neurosurgical Society
• /
• v.37 no.6
• /
• pp.405-409
• /
• 2005

Objective: The purpose of this study is to assess the factors related to the outcome of 84 patients who underwent surgery for anterior communicating Artery(ACoA) aneurysms. Methods: The authors review 84 patients who were undertaken from January 1998 to May 2004. In the management of ACoA aneurysms, the outcome was based on several factors: Clinical condition, Distribution of hemorrhage, Time between aneurysmal rupture and surgery, Direction and shape of the aneurysm. Results: The incidence rate of the ACoA aneurysm was 35%. Seventy four patients were classified as those having a good recovery, but 5 patients suffered from some morbidity and 5 patients died. The rate of good outcome for the patients with Hunt and Hess grade was as follows 100% in grade I, 95% in grade II, 80% in grade III, IV and V. The rate of good outcome for the patients with Fisher grade was as follows 98% in grade I, II and 81% in grade III, IV. Nineteen of 22 patients who underwent early surgery were rated as good, while twenty six of 30 patients for whom surgery was delayed showed a favorable result. The unfavorable outcomes were also attributed by vasospasm or other medical problems. Conclusion: For further improvement of the overall surgical outcome: First, early surgical intervention is recommended for good grade patients. Second, active management of poor grade patients should be scrutinized with early surgery. Third, it is also important to step up the effort to minimize the risk of medical complications to enhance surgical results on top of the mainstay of prevention efforts for vasospasm and rebleeding.

• Journal of the Korean Wood Science and Technology
• /
• v.13 no.4
• /
• pp.67-72
• /
• 1985

To improve the bending strength of sawdustboard, verious resin contents of 10, 13, 16, and 19% were applied to the thin shell (face layer) composed with wire net or not. The shell effect of sawdust and wire net composition formed with core sawdustboard were evaluated. Forcusing on the effects of wire net composition and noncomposition including a comparison with chipboard and veneer complyboard, bending properties (Modulus of rupture (MOR), Modulus of elasticity (MOE), Stress at proportional limit ($S_{pl}$). Work to maximum load ($W_{ml}$))were analyzed and discussed. 1. In modulus of rutpute, veneer comply was the highest (621.5 kg/$cm^2$), and next decreasing order was wire net composition (159.1 kg/$cm^2$), chipboard (81.75 kg/$cm^2$), and wire net noncomposition (76.21 kg/$cm^2$) as in modulus of elasticity, work to maximum load, except for stress at proportional limit. 2. The highly significant effects were shown in both wire net composition and noncomposition, at the same time wire net composition exceeded two times of noncomposition throughout resin contents in bending properties. Chipboard was similar to the mean or 16% resin content in noncomposirion. 3. Every board in wire net composition above 10% resin content was beyond 100 kg/$cm^2$ in MOR, minimum allowable strength for structural use according to KS F 3104. In conclusion, the feasibility for improving the bending strength of weak sawdustboard by wire net composed shell was offered.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.28 no.5
• /
• pp.563-570
• /
• 2015

The existing research on the damage detection method for building structures has considered the damages from the excessive loadings such as the earthquake. However, the structural performance of building structures could be reduced due to the deterioration based on the chloride, carbonation during the long-term time. Thus, to effectively manage the healthiness of structures, the deterioration influences on the structures should be checked. In this study, the corrosion of rebars by the chloride is considered as the deterioration factor. To consider the structural performance reduction of the corroded rebars, the yield strength, cross-sectional area, rupture strain of rebars and the compressive strength of cover concrete based on the corrosion level are estimated. These properties of rebars and cover concrete are used for the procedure to evaluate the structural performance reduction of structural member level and the building level. The moment-curvature analysis is performed to evaluate the structural performance reduction of structural member level. Also, the eigenvalue analysis and the pushover analysis are performed to investigate the natural period and mode shape and the strength and deformation performance of buildings, respectively.

• Journal of Korean Neurosurgical Society
• /
• v.30 no.sup1
• /
• pp.91-98
• /
• 2001

Objective : The purpose of this study was to investigate the prognostic factors in patients who suffered an intracerebral hemorrhage(ICH) due to a ruptured middle cerebral artery(MCA) aneurysm. Methods : Among 148 case of ruptured MCA aneurysm, ruptured MCA aneurysm with ICH was compared with ruptured MCA aneurysm alone. According to factors, the prognosis in these two groups was analyzed. Prognosis was evaluated postoperatively by applying Glasgow Outcome Scale(GOS) at discharge. Prognostic factors were evaluated with Chi square test, Mann-Whitney test and ANOVA test with differences being considered significant for value less than 0.05. Results : Ruptured MCA aneurysm alone revealed better consciousness on admission and final outcome than those combined with ICH. Ruptured MCA aneurysm alone showed 74% in H-H grade I, II and 82% in GOS I, II. But ruptured MCA aneurysm with ICH showed 63% in H-H grade IV, V and 52% in GOS IV, V. Age, sex, lesion site, aneurysmal size, temoporary clipping time, interval to operation, operative approach were statistically not significant in prognosis(p>0.05). But H-H grade on admission(p<0.05), complication(esp. cerebral infarction)(p<0.05), preoperative ICH volume and site(p<0.01), preoperative midline shifting(p<0.01), remained ICH volume(p<0.05) showed significance statistically. Conclusion : Prognostic factors are helpful to neurosurgeon to estimate clinical and neurological outcome postoperatively. We suggest that the good prognostic factors in ruptured MCA aneurysm with ICH were good H-H grade on admission, cerebral infarction(-), preoperative ICH volume <25cc, temporal and intrasylvian ICH, preoperative midline shifting <5mm, remained ICH volume <10cc.

• Journal of the Korean Society of Systems Engineering
• /
• v.18 no.2
• /
• pp.94-107
• /
• 2022

Accidents prevention and mitigation is the highest priority of nuclear power plant (NPP) operation, particularly in the aftermath of the Fukushima Daiichi accident, which has reignited public anxieties and skepticism regarding nuclear energy usage. To deal with accident scenarios more effectively, operators must have ample and precise information about key safety parameters as well as their future trajectories. This work investigates the potential of machine learning in forecasting NPP response in real-time to provide an additional validation method and help reduce human error, especially in accident situations where operators are under a lot of stress. First, a base-case SGTR simulation is carried out by the best-estimate code RELAP5/MOD3.4 to confirm the validity of the model against results reported in the APR1400 Design Control Document (DCD). Then, uncertainty quantification is performed by coupling RELAP5/MOD3.4 and the statistical tool DAKOTA to generate a large enough dataset for the construction and training of neural-based machine learning (ML) models, namely LSTM, GRU, and hybrid CNN-LSTM. Finally, the accuracy and reliability of these models in forecasting system response are tested by their performance on fresh data. To facilitate and oversee the process of developing the ML models, a Systems Engineering (SE) methodology is used to ensure that the work is consistently in line with the originating mission statement and that the findings obtained at each subsequent phase are valid.

• Journal of Korean Foot and Ankle Society
• /
• v.19 no.4
• /
• pp.151-155
• /
• 2015

Purpose: The purpose of this study was to analyze the frequency and patterns of intra-articular lesions detected during ankle fracture surgery using ankle arthroscopy. Materials and Methods: Thirty patients (31 ankles) who underwent open reduction and internal fixation combined with ankle arthroscopy for acute ankle fracture at Inje University Busan Paik Hospital from June 2011 to September 2013 were evaluated. The ankle fractures were classified according to the AO/OTA (AO Foundation and Orthopaedic Trauma Association) classification and the intraarticular injuries were identified by ankle arthroscopy. Osteochondral lesions of the talus were divided into nine subtypes based on their locations, and the ligament injuries were classified according to avulsion fracture and rupture. Results: Using arthroscopy, abnormality in the distal tibiofibular ligament was found in 21 cases and osteochondral lesions and defects of the talus larger than 5 mm were detected in 26 cases. Among ligament injuries, anterior inferior tibio-fibular ligament injury was found in 14 cases, posterior inferior tibio-fibular ligament injury was found in two cases, deep deltoid ligament injury was found in three cases, and deep transverse tibio-fibular ligament injury was found in five cases. The locations of the osteochondral lesions were on the antero-lateral, antero-medial, centro-medial, centro-central, centro-lateral, and postero-lateral talus in 11, one, two, one, two, and nine cases, respectively. Conclusion: With early diagnosis and treatment arthroscopy performed at the time of intra-articular fracture surgery is expected to result in a good outcome.

• Journal of the Korean Wood Science and Technology
• /
• v.44 no.3
• /
• pp.457-476
• /
• 2016

This was investigated on the major issues and research trends regarding the heat-treatment of woods through literature reviews. The principal heat-treatment technologies utilized for industrial purposes include the Plato-process (Netherlands), the Retification process (France), the OHT-process (Germany), and the Thermowood Process (Finland). Factors that mainly influence the heat-treatment process are the wood species, process temperature, processing time, and the heating medium (air, steam, vacuum, N2, oil, etc.). Researches on investigating the optimal conditions with these process conditions being the variables stand as the mainstream. Heat-treated woods present dimensional stability improvement, but mass loss and strength reduction, a wide variations for decaying inhibition, and insufficient resistance against mold, wood borer, and termites. For further improvement in respects of durability or resistance to biological degradation, necessity to search for more suitable heat treatment process and processing conditions fit for each wood species has been suggested. Exploiting new ways to utilize heat-treated wood and extending its range of use have been considered to be important matters that need more effort put into for the sustainable and sound environment as well as saving the wood resources.