• Journal of Korea Water Resources Association
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• v.36 no.1
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• pp.45-59
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• 2003

The method in this study, which is more efficiency than the existing method, propose the optimal rehabilitation model based on the deterioration prediction of the laying pipe by using the deterioration survey method of the water distribution system. The deterioration prediction model divides the deterioration degree of each pipe into 5 degree by using the probabilistic neural network. Also, the optimal residual durability is estimated by the calculated deterioration degree in each pipe and pipe diameter. The optimal rehabilitation model by integer programming base on the shortest path can calculate a time and cost of maintenance, rehabilitation, and replacement. Also, the model is divided into budget constraint and no budget constraint. Consequently, the model proposed by the study can be utilized as the quantitative method for the management of the water distribution system.

• Journal of Welding and Joining
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• v.26 no.5
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• pp.29-35
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• 2008

In this paper concentrate on the comparison of the thermal and mechanical characteristics in Butt joint of ship structure AH32 steel by using hybrid welding and conventional SAW. For this purpose, fundamental welding phenomena of hybrid process using $CO_2$ Laser and MIG is investigated by the experiments and characteristics of thermal and welding residual stress distribution of welded joint in SAW and hybrid welding are understood from the result of FE numerical simulation and experimental values. From the result of this study, it is understood that Laser-MIG hybrid welding have high potential, make substantial saving of time and manufacturing cost and may proves its self robust in the butt joining of thick AH32 steel ship structural plate in the near future.

• The Korean Journal of Nuclear Medicine
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• v.34 no.4
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• pp.265-275
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• 2000

The thyroid gland is an interesting endocrine organ where a spectrum of tumors with different behavior arise. At one end of spectrum there is differentiated thyroid carcinoma (DTC) with excellent prognosis, whereas at the other end of the spectrum is anaplastic thyroid cancer which has universally poor outcome. Radioiodine (I-131) therapy has been in use for the treatment of thyroid diseases since 1946. It was introduced by Seidlin et al. 1) Although the use of I-131 has been vouge for a long time, its use in therapy for well differentiated thyroid cancer is still controversial 2). This is because, thyroid cancers (TC) are generally slow growing tumors, with low mortality and normal spans of survival. To record recurrence and mortality, long term follow up studies over a period of two to three decades are needed to establish definite conclusions on the acceptable mode of treatment The incidence of the disease being very low a large number of cases needed to establish a meaningful statistical data is lacking as most published reports feat with small series. Here again in the problem encountered are the differing protocols for treatment with I-131, the indications for treatment which may include or exclude ablation of residual thyroid tissue, cervical nodal and distal metastases. The dosage of I-131 used for ablation of residual thyroid tissue and metastatic disease also vary. The most reliable conclusion regarding I-131 treatment are obtained from studies reported on a large series of patients followed over a period of 2 decades or more from a single institute with a more or less unchanged protocol of management.

• The Journal of the Acoustical Society of Korea
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• v.38 no.5
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• pp.568-573
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• 2019

In the diagnosis of pulmonary diseases, auscultation technique is simpler than the other methods, and lung sounds can be used for predicting the types of pulmonary diseases as well as identifying patients with pulmonary diseases. Therefore, in this paper, we identify patients with pulmonary diseases and classify lung sounds according to their sound characteristics using various convolutional neural networks, and compare the classification performance of each neural network method. First, lung sounds over affected areas of the chest with pulmonary diseases are collected by using a single-channel lung sound recording device, and spectral features are extracted from the collected sounds in time domain and applied to each neural network. As classification methods, we use general, parallel, and residual convolutional neural network, and compare lung sound classification performance of each neural network through experiments.

• Journal of Clinical Otolaryngology Head and Neck Surgery
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• v.29 no.2
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• pp.198-203
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• 2018

Background and Objectives : Pediatric orbital blowout fractures occur in discreet patterns, in reference to the characteristic developmental anatomy of the facial skeleton at the time of injury. The purpose of this study was to investigate the clinical characteristics, ocular symptom, fracture type and postoperative results of orbital blowout fractures in the pediatric population. Material and Methods : A retrospective study was conducted from January 2009 to June 2015 in 116 patients with orbital floor fractures ; all less than 18 years old. Patients were divided into 3 groups by age : 0 to 6, 7 to 12, and 13 to 18 years of age. The cause of fracture, fracture site and type, preoperative and postoperative ocular symptoms, timing of surgery were reviewed from their records. Results : Medial wall fractures were the most common site in the 0 to 6 years old group, and floor fractures were the most common site in other age groups. However, floor fracture was the most common site of the need for surgery in all age groups. Trapdoor type of fractures occurred more frequently than open door type of fractures in all age groups. Preoperative symptoms did not differ among the 3 age groups. In case of need surgery, frequency of preoperative ocular symptoms increased with age. However, as age group was young, rate of residual postoperative ocular symptoms were increased. Conclusions : The younger patients are more to have trapdoor type fracture and residual postoperative ocular symptom. Earlier surgical intervention more needed for children with entrapment results.

• Journal of Advanced Navigation Technology
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• v.23 no.3
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• pp.251-257
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• 2019

The configuration of ultra-long optical transmission link with dispersion management and optical phase conjugation is proposed. The whole transmission link consist of 80 km (single mode fiber span) ${\times}$ 56 fiber spans. The artificial distribution of single mode fibers' lengths and residual dispersions in fiber spans, which are gradually increased/decreased as the span number is increased, is adopted to compensate for the distorted wavelength division multiplexed channels. Since the compensation effect through the artificial distribution in the previous researches is expected to decrease as the number of fiber spans are increased, three-time repetition of the artificial distribution patterns at intervals of 9 fiber spans applied into the link with dispersion management and optical phase conjugation is proposed. From the simulation results, it is confirmed that the compensation in the link configured by the special distribution pattern among 4 proposed patterns is slightly improved than the link configured by the conventional method, which is designed by the repeat-less distribution pattern.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.5
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• pp.533-539
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• 2019

This study proposes a malware classification model that can handle arbitrary length input data using the Microsoft Malware Classification Challenge dataset. We are based on imaging existing data from malware. The proposed model generates a lot of images when malware data is large, and generates a small image of small data. The generated image is learned as time series data by Dynamic RNN. The output value of the RNN is classified into malware by using only the highest weighted output by applying the Attention technique, and learning the RNN output value by Residual CNN again. Experiments on the proposed model showed a Micro-average F1 score of 92% in the validation data set. Experimental results show that the performance of a model capable of learning and classifying arbitrary length data can be verified without special feature extraction and dimension reduction.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.5
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• pp.101-106
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• 2019

This paper propose the VSS-FC-MMA algorithm that is possible to improve the equalization performance based on varying step size to the FC-MMA adaptive equalization algorithm in order to reducing the intersymbol interference effect occurred in the nonconstant modulus signal transmission, and improved performance were confirmed. The FC-MMA is possible to improve the convergence speed, and degrades the steady state performance based on the fixed step size and modified dispersion constant considering the level number of signal symbol for obtain the error signal in adaptive equalization compared to MMA. The proposed VSS-FC-MMA uses varying step size and current FC-MMA possible to improve the steady state equalization performance, it was confirmed by computer simulation. For this, the signal recovery capabilities and residual isi, MSE, SER were applied for performance comparison index in the same channel and signal to noise ratio. As a result of computer simulation, the proposed VSS-FC-MMA improve the risidual value in steady state and SER performance than the FC-MMA, but has 1.7 times slow convergence time by using varying step size.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.1
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• pp.55-60
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• 2021

This paper relates with the performance evaluation of QE-MMA (Quantized Error-MMA) adaptive equalization algorithm based on the stepsize and quantizer bit number in order to reduce the intersymbol interference due to nonlinear distortion occurred in the time dispersive channel. The QE-MMA was proposed using the power-of-two arithmetic for the H/W implementation easiness substitutes the multiplication and addition into the shift and addition in the tap coefficient updates process that modifies the SE-MMA which use the high-order statistics of transmitted signal and sign of error signal. But it has different adaptive equalization performance by the step size and quantizer bit number for obtain the sign of error in the generation of error signal in QE-MMA, and it was confirmed by computer simulation. As a simulation, it was confirmed that the convergence speed for reaching steady state depend on stepsize and the residual quantities after steady state depend on the quantizer bit number in the QE-MMA adaptive equalization algorithm performance.

• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.368-374
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• 2020

BACKGROUND: The residual analysis of polar pesticides has remained a challenge. It is even more difficult to simultaneously analyze multiple polar pesticides. Diquat, paraquat, and chlormequat are typical examples of highly polar pesticides. The existing methods for the analysis of diquat, paraquat and chlormequat are complex and time consuming. Therefore, a simple, quick and effective method was developed in the represent study for simultaneous analysis of diquat, paraquat and chlormequat in animal products, meat and fat using UPLC-MS/MS. METHODS AND RESULTS: Sample extraction was carried out using acidified acetonitrile and water and re- extracted with acidified acetonitrile and combine the extracts followed by centrifugation. The extract was then cleaned up with a HLB cartridge after reconstitution with acidic acetonitrile and water. The method was validated in quintuplicate at three different concentrations. The limits of detection (LOD) and quantification (LOQ) were 0.0015 and 0.005 mg/L, respectively. Matrix suppression effect was observed for all of the analytes. A seven point matrix matched calibration curve was constructed for each of the compound resulted excellent linearity with determination coefficients (R2) ≥ 0.991. Accuracy and precision of the method was calculated from the recovery and repeatability and ranged from 62.4 to 119.7% with relative standard deviation less than 18.8%. CONCLUSION: The recovery and repeatability of the developed method were in the acceptable range according to the Codex Alimentarius guideline. The developed method can be applied for the routine monitoring of diquat, paraquat, and chlormequat in animal products, meat and fat.