• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.154-164
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• 2011

This study was conducted to develop the semi-crawler type mini-forwarder that can be operated comfortable small-scale logging operation in the steep terrain and also used at a variety of operations such as the civil work in erosion control and forest-road. Considering the minimum turning radius and the width of forest operation road, the total length, width and loading capacity of the semi-crawler type mini-forwarder is 5,750 mm, 1,900 mm and $2.5m^{3}$, respectively. The maximum engine power is 96ps at 3600 rpm. Selected hydraulic pumps are consists of two main pumps and two sub-main pumps. Main hydraulic pumps are utilized to running motor of the front wheel and rear crawler. Sub-main pumps are utilized to the actuation parts such as steering, crane, out-rigger and dump cylinder. The transmission was adapted as the HST (Hydro-Static Transmission) system. The driving parts are designed and manufactured as the front wheel type and the rear crawler type. The steering type was manufactured as the ackerman type. Driving control parts type was designed and manufactured as driver's seat type of normal cars. It is also attached on auxiliary equipments such as winch, log grapple and out-rigger. The traveling speed of the semi-crawler type mini-forwarder in forest road was 5.3 km/hr to 7.7 km/hr.

• Journal of Korean Academy of Nursing
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• v.36 no.7
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• pp.1232-1241
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• 2006

Purpose: The purpose of this study was to examine the effects of cerebral ischemia on Type I(soleus) and Type II(plantaris, gastrocnemius) muscles, and to determine the effects of isometric contraction training by electro- stimulation on Type I and II muscles in cerebral ischemia model rats. Method: Twenty-five male Sprague-Dawley rats were randomly divided into four groups: ST(stroke), STES(stroke+electrostimulation), SH(sham) and SHES (sham+electrostimulation). The ST and STES groups received a transient right middle cerebral artery occlusion operation. The SH and SHES groups received a sham operation. The STES and SHES groups had daily isometric contraction training by electrostimulation(100Hz, 45mA, 7.5V) on hindlimb muscles for 7days. Result: Plantaris and gastrocenmius muscle weight, myofibrillar protein contents of soleus and gastrocnemius, and the muscle fiber cross-sectional area of gastrocnemius in the ST group significantly decreased compared with the SH group. Soleus, plantaris, gastrocnemius muscle weight, myofibrillar protein contents of soleus and gastrocnemius, and the Type I muscle fiber cross-sectional area of soleus and the Type II muscle fiber cross-sectional area of gastrocnemius in the STES group significantly increased compared with the 57 group. Conclusion: Hindlimb muscle atrophy occurs after acute stroke and isometric contraction training by electrostimulation during early stages of a stroke attenuates muscle atrophy of Type I and Type II muscles.

• Advances in pediatric surgery
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• v.10 no.2
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• pp.92-98
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• 2004

The history of esophageal replacement in infants or children is the history of development of various kinds of alternative conduits such as stomach, colon, and small bowel. The gastric tube has been the most widely used conduit. From January 1988 to May 2003, 23 esophageal replacements with gastric tube were performed at the Department of Pediatric Surgery, Seoul National University Childrens Hospital. Statistical analysis was performed using Windows SPSS11.0 Pearson exact test. There were Gross type A(n=10), type B(n=1), type C(n=11), type D(n=1). Ten patients who had long gap esophageal atresia (type A-8, type B-1, type C-1) and 13 patients (type A 2, type C-10, type D-1) who had stenosis, leakage, recurred tracheoesophageal fistula, and esophagocutaneous fistula after previous corrective operations, had esophageal replacement with gastric tube. Mean follow-up periods were 4 year 2 months (7 months-15 year 1 month). There were postoperative complications including GERD in 16 (69.6 %), leakages in 7 (30.4 %), diverticulum at anastomosis in 2 (8.7 %), anastomosis site stenosis in 4 (17.3 %), and distal stenosis of the gastric tube in 1 (4.3 %). There was no statistical significance between operation types and postoperative leakage and gastroesophageal reflux. In conclusion, esophageal replacement with gastric tube may be a useful surgical option in esophageal atresia with long gap and esophageal atresia complicated by previous corrective operation.

• Annals of Surgical Treatment and Research
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• v.95 no.5
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• pp.249-257
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• 2018

Purpose: Multidrug resistance-associated protein (MRP) 2 is a glutathione conjugate in the canalicular membrane of hepatocytes. Early graft damage after liver transplantation (LT) can result in alteration of MRP2 expression. The purpose of this study was to evaluate the relationship between the pattern of MRP2 alteration and graft outcome. Methods: Forty-one paraffin-embedded liver graft tissues obtained by protocol biopsy within 2 months after LT; these were stained using monoclonal antibodies of MRP2. We selected 15 live donor biopsy samples as a control, that showed homogenous canalicular staining for MRP2. The pattern of canalicular MRP2 staining of graft was classified into 3 types: homogenous (type C0), focal (type C1), and no (type C2,) staining of the canaliculi. Results: In total, 17.1% graft tissues were type C0, 36.6% were type C1, and 46.3% were type C2. The median operation time was longer in patients with type C2 (562.6 minutes) than in patients with type C0 (393.8 minutes) (P = 0.038). The rates of posttransplant complications were higher in patients with type C2 (100%) than in patients with type C0 (42.9%) and C1 (73.3%) (P < 0.001). Conclusion: MRP2 expression pattern was altered in 82.9% after LT. The pattern of MRP2 alteration was associated with longer operation time and higher rates of post-LT complications.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1993.10a
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• pp.71-75
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• 1993

The Modeling analysis and design of a high frequency LC-type series and LLCC-type parallel resonant converter oprating in the continous conduction is presented. The state-plane diagram representation of the converter response gives and good insight into the converter operation. A set of characterisric frequency are plotted which design parameters can be obtained.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.4
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• pp.169-176
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• 2017

This paper presents research on low-voltage microgrids to maintain a continuous power supply to critical loads on grid-connected islands in Korea. The low-voltage microgrids of this paper focused on that changes public office buildings into uninterrupted microgrids by autonomous operation. For this, a microgrid controller (MGC) and a power conditioning system (PCS) that allow a seamless transfer between grid-connected and grid-isolated operation are proposed. The proposed PCS operates with a silicon controlled rectifier (SCR) switch and employs a simple structure. It supplies power continuously without operators through a coordinated operation between MGC and PCS. In addition, proposed MG has a schedule operation for minimizing electricity charges and provides ancillary services that enable the utilization of resources according to the operation purpose of utility distribution networks. To demonstrate the uninterrupted low-voltage microgrid proposed in this study, a microgrid was implemented and tested in a public office building in Anjwa Island, Jeollanam-do in Korea. A seamless, autonomous operation history, despite system disturbances, was obtained through a long-term demonstration of operation. The results showed that the proposed microgrid technology can be used to achieve energy resilience in grid-connected island areas.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.435-443
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• 2016

This paper describes the development of a dry operation process for PWR spent nuclear fuel, which is currently stored in the domestic NPP's storage pool, using a dual purpose metal cask. Domestic NNPs have had experience with wet type transportation of PWR spent nuclear fuel between neighboring NPPs since the early 1990s, but no experience with dry type operation. For this reason, we developed a specific operation process and also confirmed the safety of the major cask components and its spent nuclear fuel during the dual purpose metal cask operation process. We also describe the short term operation process that was established to be completed within 21 hours and propose the allowable working time for each step (15 hours for wet process, 3 hours for drain process and 3 hours for vacuum drying process).

• Journal of the Korean Society for information Management
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• v.41 no.1
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• pp.59-83
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• 2024

The directions of recent library construction and operation reflect people's changed lifestyle and suggest innovative spaces specialized on the basis of the local environment. Hence, as the goals of the operation of (tentatively named) Songdaeso Library to be constructed within the Hantangang River UNESCO Global Geopark, this study proposes 'acting as complex cultural facilities,' 'operating stay-type reading culture space which is a shrine for workcation,' and 'acting as the landmark of A-gun (郡, county).' And this study works out strategies for its operation, which includes 'securing the validity of the construction of (tentatively named) Songdaeso Library,' 'linking to library policy as the driving force behind its operation,' and 'demonstrating the necessity for the existence of the library arising from the operation of the geological specialized library through landscape architecture.' It also presents concomitant operating plans, which are categorized into plans for manpower, library books, services, and budget.

• Journal of Chest Surgery
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• v.9 no.2
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• pp.251-264
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• 1976

Forty three patients with disease of the aorta were admitted in this department during the period from beginning of 1956 to the end of 1976. They consisted of eighteen cases of aortic aneurysms, eight cases of Takayasu's arteritis, eight Leriche syndromes, six dissecting aneurysms, two aortic coarctations and one case of vascular ring. Of eighteen aortic aneurysms, twelve were operated resulting in eight survivors. Three of four mortalities were in shock preoperatively because of aneurysmal rupture. Among six dissecting aortic aneurysms, four were type III and two were type I according to DeBakey's classification. For the purpose of relief of acute arterial insufficiency in the lower extremities, a re-entry operation grafting a Y-shaped dacron vessel between abdominal aorta and common iliac arteries was performed. The patient regained consciousness soon after the operation and was well until postoperative second day, when severe convulsion developed abruptly and died. And in a chronic case of type III dissecting aneurysm, a dacron graft bypass shunt between ascending aorta and lower descending thoracic aorta with resection of the aneurysm was performed, but acute severe aortic insufficiency developed soon after the operation and fell into intractable heart failure resulting in death. The cause of the aortic insufficiency seems to be retrograde dissection from the proximal anastomosis site in the ascending aorta. Three cases were treated medically with Wheat's regimen. Two of them survived with relief of symptoms. Eight patients of Takayasu's arteritis were all females and aged between twenty and forty-four averaging twenty nine. Bypass graft operation between aortic arch and carotid arteries using Y-shaped nylon prostheses were performed in three patients resulting in death in two cases postoperatively due to severe cerebral arterial insufficiency during the procedure. All the patients with Leriche syndrome were males and over forty. In two cases, bypass graft with Y-shaped dacron vessel between terminal aorta and common iliac or femoral arteries were performed with good result. Thromboembolectomy or thromboendarterectomy was employed in three patients, of whom one was aggravated in sexual problem postoperatively. One out of two aortic coarctations and a vascular ring were treated surgically with excellent results.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.2
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• pp.184-191
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• 2000

We discussed load CUlTent sharing for Master/Slave convertedMSC) type two DC-DC Converters parallel operation using a single current sensor method. In the conventional method, two CTs have been used to share t the load CUlTent equally with two coηverters‘ This paper presents a novel load CUlTent distribution method u using a single CUlTent sensor that can share load CUlTent effectively with only one CT in the Master-Slave C conveη:ers(MSCs) type. To confirm parallel operational performance of proposed DC-DC converters parallel operation, two experimental prototype converters were designed, implemented and experimented under three a arbitrary conditions. A load cur‘rent shahring perforrnance of the proposed method was compared with that of a c conventional peak CUt${\gamma}$ent method requmng two CTs. Those experimental results show that load cUlTent s sharing performance of paralleled two converters using a single CUlTent sensor was good and operated as well a as conventional method (ex, Pe밟 CUlTent Method)