• Archives of Plastic Surgery
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• v.46 no.5
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• pp.449-454
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• 2019

Background Most patients with head and neck cancer successfully undergo oncologic resection followed by free or local flap reconstruction, depending on the tumor's size and location. Despite effective curative resection and reconstruction, head and neck cancer patients still face a high risk of recurrence and the possibility of a second primary cancer. Moreover, surgeons hesitate to perform sequential reconstruction following curative resection for several reasons. Few large-scale studies on this subject are available. Therefore, we retrospectively evaluated the outcome of sequential head and neck reconstruction to determine the possible risks. Methods In total, 467 patients underwent head and neck reconstruction following cancer resection at our center from 2008 to 2017. Of these cases, we retrospectively reviewed the demographic and clinical features of 58 who had sequential head and neck reconstruction following resection of recurrent cancer. Results Our study included 43 males (74.1%) and 15 females (25.9%). The mean age at the initial operation was $55.4{\pm}15.3years$, while the mean age at the most recent operation was $59.0{\pm}14.3years$. The interval between the first and second operations was $49.2{\pm}62.4months$. Twelve patients (20.7%) underwent surgery on the tongue, and 12 (20.7%) had procedures on the oropharynx. Thirty-four patients (58.6%) received a sequential free flap reconstruction, and 24 patients (41.4%) were treated using locoregional flaps. No cases of flap failure occurred. Conclusions Our findings suggest that patients who need additional operations with recurrent head and neck cancer could optimally benefit from sequential curative resections and reconstructions.

• Journal of Advanced Navigation Technology
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• v.25 no.1
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• pp.52-59
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• 2021

According to the International Air Transport Association (IATA), 61% of the accidents occurred during the approach and landing phase of the flight, with 16% of the accidents caused by unstable access of the commercial aircraft. It was identified that the pilot's unstable approach and poor manipulation of correction led to accidents by continuing the excessive approach without go-around manuever. The causes of unstable access may vary, including airport approach procedures, pilot error, misplanning, workload, ATC (Air Traffic Contol) congestion, etc. In this study, we use the flight data analysis system to select domestic case airports and aircraft type where unstable approach events occur repeatedly. Through flight data analysis, including main events, airport approach procedures, pilot operations, as well as various environmental factors such as weather and geographical conditions at the airport. It aims to identify and eliminate the tendency of unstable approach events and the causes and risks of them to derive implications for mitigating unstable approach events and for developing navigation safety measures.

• The Journal of the Korea Contents Association
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• v.7 no.7
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• pp.124-132
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• 2007

In hospitality industry many firms choose the franchise system in order to enlarge their market share and to decrease risks. Small businessmen also accept the franchise contract as a good way of starting their business. With the contract franchisees take advantages of marketing, fiance, and operations from franchisers by paying several related fees or royalties. In this study factors influencing franchisees' satisfaction for the contract were identified. And the study also found that there was a significant difference in the degree of influencing among the factors.

• Asian Journal of Atmospheric Environment
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• v.8 no.1
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• pp.1-14
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• 2014

Migration of methane ($CH_4$) gas from landfills to the surrounding environment negatively affects both humankind and the environment. It is therefore essential to develop management techniques to reduce $CH_4$ emissions from landfills to minimize global warming and to reduce the human risks associated with $CH_4$ gas migration. Oxidation of $CH_4$ in landfill cover soil is the most important strategy for $CH_4$ emissions mitigation. $CH_4$ oxidation occurs naturally in landfill cover soils due to the abundance of methanotrophic bacteria. However, the activities of these bacteria are influenced by several controlling factors. This study attempts to review the important issues associated with the $CH_4$ oxidation process in landfill cover soils. The $CH_4$ oxidation process is highly sensitive to environmental factors and cover soil properties. The comparison of various biotic system techniques indicated that each technique has unique advantages and disadvantages, and the choice of the best technique for a specific application depends on economic constraints, treatment efficiency and landfill operations.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.309-312
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• 2009

The various hazards should be eliminated before operations for the successful launches or tests. Using the contaminated propellants is one of the causes for the launch and test failures. Especially, the systems using liquid oxygen as an oxidizer have risks about fires and explosions not be forecasted if they are contaminated by oil, water and mechanical impurities. The procedure for the quality control of the liquid oxygen and the liquid oxygen filling system and the lessons learned from the first launch preparation with the system are introduced on this paper.

• Journal of the Korea Safety Management & Science
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• v.16 no.3
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• pp.9-22
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• 2014

Constructions sites are affected by Diversity workplace, complexity of construction, Change of place, Mobility of workers and so on. In a single establishment, Prime contractors and subcontractors have to conduct their work at the same time. There are a lot of unpredictable risks when the construction is running, coordination between contractors is very important to do a risk assessment under the condition. Large Construction companies were investigated by previous studies. Survey research is applied to the risk assessment. In the writing, Risk assessment of the entire lower level. Because of the low level of risk factors to find. Also, There was a limit to investigate accidents. Confirmed that Effort to derive a risk factors were desperately of the risk assessment. Results were obtained through previous studies. The PCM is several experts should be joined. Experts Site Manager, Supervisor, Safety Manager, Director Contractor, Work team leader is required to participate. Construction plans, Process Planning to the risk find beforehand. And Determines how the operations and the control. Also, Made it into the database. and PCRA can be used in the risk assessment was developed.

• Journal of Chest Surgery
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• v.26 no.2
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• pp.108-114
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• 1993

The risks of homologous blood transfusion are well documented and recently increased with the emergence of acquired immunodeficiency syndrome. This is a report concerning 29 consecutive adult with no blood conservation patients (Group I) who had an elective cardiac operations. A similar group of 29 patients operated on 1992 but with blood conservation (Group II). In I of Group I patients and 15 of Group II patients, no homologous blood products were required. Group II patients used significantly less fresh frozen plasma (2.05${\pm}$0.68 unit versus 6.52${\pm}$0.72 unit, p<0.05) and the homologous blood transfusion (0.42${\pm}$0.9 unit versus 3.64${\pm}$0.17 unit, p<0.05) than Group I patients. Group II patients had also significantly less postoperative bleeding (338${\pm}$39.9 ml versus 585${\pm}$93.0 ml, p<0.05) than Group I patients. Group II patients recieved 460${\pm}$62.6 ml of mediastinal shed blood in acquired group. In conclusion, a simple and inexpensive blood conservation program, mainly combining autologous blood removal before bypass, retransfusion of the volume remaining in the oxygenator, and consistent autotransfusion of mediastinal shed blood has enabled us to avoid infusion of homologous blood in 15/29 patients of Group II patients. No side effects or complicatinos could be related to the blood conservation program.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.1180-1200
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• 2017

Currently, automated payment services provide intuitive user interfaces by adapting various wireless communication devices with mobile services. For example, companies like Samsung, Google, and Apple have selected the NFC payment method to service payments of existing credit cards. An electronic payment standard has been released for NFC activation within Korea and will strengthen the safety of payment service communications. However, there are various security risks regarding the NFC-based electronic payment method. In particular, the NFC payment service using the recently released lightweight devices cannot provide the cryptographic strength that is supported by many financial transaction services. This is largely due to its computational complexity and large storage resource requirements. The chaotic map introduced in this study can generate a highly complicated code as it is sensitive to the initial conditions. As the lightweight study using the chaotic map has been actively carried out in recent years, associated authentication techniques of the lightweight environment have been released. If applied with a chaotic map, a high level of cryptographic strength can be achieved that can provide more functions than simple XOR operations or HASH functions. Further, this technique can be used by financial transaction services. This study proposes a mutual authentication technique for NFC-PCM to support an NFC payment service environment based on the chaotic map.

• Korean journal of food and cookery science
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• v.8 no.2
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• pp.123-135
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• 1992

Time and temperature conditions, and microbiological qualities of six categories of menu items were assessed according to the process of food product Row in a 500 bed general hospital. The Harzard Analysis Critical Control Point (HACCP) system was applied to determine harzards, to assess their severity and risks, and to identity CCPs and memos for monitoring mem. The Critical Control Points identified for each category of menu items were: Meat Soup (Kyung Sang Do Gogi Guk): Pre-preparation, holding after pre-preration, and holding after cooking; Pot Stewed Stuffed Cabbage (Soe Yangbaechu Mali Chim): pre-preparation, holding after Pre-preparation, stuffing, cooking and holding after cooking; Boned Pork Sour Salad (Doeji Suyuk Muchim): Pre-preparation, holding after pre-preparation, and post-preparation after cooking; Sauteed Pork Ball (Jeyuk Wanja Jon): pre-preparation, holding after pre-preparation, shaping, and holding after cooking; Stir-fried Fragrant Mushroom (Pyogo Bosot Bokkum): basic ingredients, Pre-preparation, holding after pre-preparation, and holding after cooking; and Fried Corn with Vegetables (Oksusu Yachae Tuigim): pre-preparation, holding after pre-preparation, mixing, and holding after cooking.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.105-109
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• 2015

In this paper is proposed for the oil return device developed to perform efficient emergency operation in the event the sea oil spill. Oil recovery apparatus for spilled oil on marine aims to quickly purged with high recovery. Oil recovery apparatus can prevent secondary pollution which may occur in the purification method using the adhesion agent and chemicals. Also it has excellent properties oil recovery. Adopted by the vapor explosion-proof mechanism to remove the risks that may occur during oil recovery operations.