• Journal of the military operations research society of Korea
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• v.11 no.1
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• pp.33-46
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• 1985

This study develops a scientific method in pilot selection by analysing a divided attention performance between the successful pilots and the failures in a flight training course. To measure the divided attention performance, Dual Task Method is used in which the primary task is a tracking task while the secondary tasks are, 1. short-term memory task 2. choice reaction task 3. judgement task. Result shows that the performance of the pilots is significantly better (p < 0.1) than that of the failures in divided attention performance. In addition, the differences in the divided attention performance between the two groups are increased in proportion to the difficulty of the task and especially in the short term memory, the increment is most dramatic.

• Journal of Chest Surgery
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• v.13 no.3
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• pp.292-297
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• 1980

The congenital cystic adenomatoid malformation of the lung consists of an enlarged, meaty, multicystic lobe with smooth-walled cysts of varying sizes, which can communicate with major bronchi through malformed air passages that usually lacks cartilage. This abnormality is usually symptomatic in infancy with signs of respiratory distress such as tachypnea, substernal retraction and cyanosis. Prompt surgical resection is choice of treatment in life-threatening respiratory distress patients. We recently experienced a case of congenital cystic adenomatoid malformation of the lung in a patient with situs inversus totalis. The patient was 40 days old female who showed severe respiratory difficulty. Emergency left middle lobectomy was undergone successfully. Her postoperative course was uneventful. She was discharged from hospital on the postoperative eighth day in good condition.

• Korean Journal of Bronchoesophagology
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• v.13 no.2
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• pp.65-67
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• 2007

Congenital epiglottic cyst is rare cause of stridor in neonate and if managed inadequately, disaster such as death can occur. Diagnosis of congenital epiglottic cyst includes imaging studies and endoscopy. Fiberoptic or rigid endoscopic examination excludes other causes of stridor in neonate. Complete excision of cyst is treatment of choice under suspension laryngoscopic guidance. Here, we report a case of congenital epiglottic cyst and concomitant laryngomalacia presenting with seizure and respiratory difficulty in neonate with a review of literature.

• Journal of Korean Institute of Industrial Engineers
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• v.10 no.2
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• pp.3-16
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• 1984

This study develops a scientific method in pilot selection by analysing a divided attention performance between the successful pilots and the failures in a flight training course. To measure the divided attention performance, Dual Task Method is used in which the primary task is a tracking task while the secondary tasks are, 1. short term memory task, 2. choice reaction task and 3. judgement task. Result shows that the performance of the pilots is significantly better (P < 0.1) than that of the failures in dual performance. In addition, the differences in the divided attention performance between the two groups are increased in proportion to the difficulty of the task and especially in the Short Term Memory, the increment is most dramatic.

• The Journal of the Korean dental association
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• v.50 no.11
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• pp.670-676
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• 2012

Distraction osteogenesis and orthognathic surgery are the widely used surgical methods for treating hemifacial microsomia and cleft lip and palate, the representative forms of congenital deformity. Distraction osteogenesis is an outstanding treatment of choice when more traction is needed than what can be achieved by general orthognathic surgery. However, the stability of distraction osteogenesis has not yet been established, and in most of the cases, additional orthognathic surgery is mandatory. Moreover, the difficulty in precise control of the traction directions is another disadvantage of distraction osteogenesis. Therefore, it would be desirable not to conduct distraction osteogenesis when the patient is suitable for an orthognathic surgery. Also, distraction osteogenesis should be recognized as an accessorial method of treatment, and be used restrictively.

• Journal of the Korean Mathematical Society
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• v.42 no.6
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• pp.1287-1309
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• 2005

A key exchange protocol using commutative subalge-bras of a full matrix algebra is considered. The security of the protocol depends on the difficulty of solving matrix equations XRY = T, with given matrices R and T. We give a polynomial time algorithm to solve XRY = T for the choice of certain types of subalgebras. We also compare the efficiency of the protocol with the Diffie-Hellman key exchange protocol on the key computation time and the key size.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.3
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• pp.32-37
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• 2005

Several types of smart materials and control scheme are available to adjust the structure actively in various external disturbances. A control scheme was introduced for a specific material. But the effectiveness of the control scheme has some limitation according to the choice of the smart materials and the response of the structure. The ER(Electrorheological) fluid is adequate for a large control force, and the PZT(lead zirconate titanate) patches are suitable for small but arbitrary control force at any point of the structure. It can be used for active control of structure by changing the dynamic characteristics of the structure. But it has some difficulty in suppressing the excited vibration in broad band. To compensate this resonance of the controlled structure, a hybrid controller was constructed using PPF(Positive position feedback) control with PZT and ER fluid control.

• Journal of Information Technology Services
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• v.4 no.1
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• pp.141-148
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• 2005

The importance of education is greatly emphasized in the IT era. However, teachers have to deal with teaching work as well as increasing non-educationalchores. One of those chores is student counseling. Nowadays, teachers have considerable difficulty in consulting students because they cannot visit their home and don't have enough information on students. Furthermore, students are not willing to participate in school counseling since they think school counseling is not of much help and is just time-consuming. Most of the current school counseling is focused on matters related to entrance into a school of higher grade such as choice of college. But, students need counseling on matters regarding their ordinary life. This paper suggests a web-based student-counseling system that may solve this problem. The paper identifies core requirements for the web-based student-counseling system, discusses its design and implementation and shows it is more effective than the current ordinary school counseling by experimenting on a group of students with this system.

• The Journal of the Korea Contents Association
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• v.6 no.2
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• pp.93-98
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• 2006

The paper describes a method o( user feedback in order to enhance the retrieval system effectiveness. The existing fuzzification function adapting fuzzy technique has difficulty that 4 type graph is made each time user select components. In this paper, to overcome this weak point of feedback, we proposed the interaction function using gaussian function that gives different learning rate according to choice of components with same function. We suggest the most efficient dynamic interaction function based on comparison of retrieval performance according to parameter of function. And then, we will construct the efficient retrieval system.

• Journal for History of Mathematics
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• v.14 no.1
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• pp.47-60
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• 2001

The present study develops the given theme “Mathematics and Reality” along two lines. First, we explore the answers, in its various facets, to the following question: How is it possible that mathematics shows such wondrous efficiency when explaining nature\ulcorner In addition to a comparative analysis between empiricism and rationalism, constructivism as a function of idealism is compared with realism within the frame provided by rationalism. The second step involves limiting our discussion to realism. We attempt to explain the various stages of mathematical realism and their points of difficulty. Postulate of parallels, Godel's theorem, continuum hypothesis and choice axiom are typical examples used in demonstrating undecidable propositions. They clearly show that it is necessary to mitigate the mathematical realism which depends on bivalent logic based on an objective exterior world. Lowenheim-Skolem theorem, which states that reality is composed not of one block but rather of diverse domains, also reinforces this line of thought. As we can see the existence of undecidable propositions requires limiting the use of reductio ad absurdum proof which depends on the concept of excluded middle. Consequently, it becomes obvious that bivalent logic must inevitably cede to a trivalent logic since there are three values involved: true, false, and undecidable.