• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.651-658
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• 2004

In this study, we introduced the spiral pipe nailing system (refer as SPN system) with self drilling method, can apply to ground which is hard to keep shape of bore hole, and performed limit equilibrium analysis with simplilied trial wedge method while length ratio and bond ratio were altered to evaluate slope stability considered of tensile strength and bending stiffness. A newly soil nailing system named as the SPN system is respected to reduce displacement of nail and increase global slope stability. And effects of various factors related to the design of the SPN system, such as the type of drilling method and the bit, are examined throughout a series of the displacement-controlled field pull-out tests. 6 displacement-controlled field pull-out tests are performed in the present study and the volume of grouting arc also evaluated based on the measurements. In addition, short-term characteristics of pull-out deformations of the newly proposed SPN system are analyzed and compared with those of the general soil nailing system by carrying out the displacement-controlled field pull-out tests.

• The KIPS Transactions:PartC
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• v.9C no.4
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• pp.445-452
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• 2002

In this paper, we suggest the design of 128bit block cipher which is provable security based on mathematics theory. We have derived the 16$\times$16 matrix(i.e.,linear transformation) which is numerous active S-box, and we proved for DC and LC which prove method about security of SPN structure cipher algorithm. Also, the minimum number of active S-box, the maximum differential probabilities and the maximum linear probabilities in round function of 128bit block cipher algorithm which has an effect to DC and LC are derived.

• Proceedings of the Korea Society for Simulation Conference
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• 1992.10a
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• pp.9-9
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• 1992

시뮬레이션(simulation)은 실 시스템(real system)의 효과적이고 효율적인 운영을 도모하기 위하여 실 시스템의 동작을 이해하고 분석, 예측, 평가하는 과학적인 문제해결 접근방법이다. 시뮬레이션 수행단계는 실 시스템의 행위를 정확히 반영하도록 타당한 모델을 구축하는 모델링 단계와 모델에 의도하는 명령어들을 컴퓨터 프로그램으로 작성하는 구현단계로 나누어진다. 시뮬레이션 모델은 시간, 상태, 확률변수, 상호규칙 등의 여러 관점에 따라 다양하게 존재하는데, DEVS(Descrete EVent system Specification) 모델은 연속적인 시간상에서 이산적으로 발생하는 사건에 따라 시스템의 상태를 분석할 수 있고 모델링 및 시뮬레이션 방법론의 형식화를 위한 견고한 이론적 기반을 제공하고 있다. 또한, DEVS 모델은 모듈적, 계층적 특성을 제공하고 집합론에 근거한 수학적 형식구조를 제공하여 실 시스템에 대한 체계적인 분석과정을 수행하게 되어 보다 현실적인 모델링을 가능하게 한다. 그러나 타당하지 못한 DEVS 모델이 구축되면 시뮬레이션을 통한 분석결과의 신뢰성이 떨어져 아무런 효과가 없고 경제적인 손실만이 따른다. DEVS 모델에 대한 기존의 타당성 검사가 많은 시간과 노력이 요구되고, 반복적인 DEVS 모델링 과정으로 인한 전문적이고 경험적인 지식을 요구한다. 또한, 모델설계자에 의해 설정된 실험 프레임하에서 DEVS 모델의 구성요소에 속하는 상태전이함수, 시간진행함수 및 출력함수에 대하여 commutative 성질의 보전성 검사가 어렵다는 문제점을 가지고 있다. 본 연구에서는 이와 같은 문제점을 해결하기 위하여, DEVS 모델에 대한 타당성 검사를 SPN(Stochastic Petri Net) 모델로 변환하여 SPN 모델을 이용하는 간단하고 효과적인 타당성 검사 방법을 제안한다. 먼저, DEVs 모델에 대한 개념과 기존의 DEVS 모델에 대한 타당성 검사 방법을 고찰하고 그 문제점에 대하여 자세히 설명한다. DEVS 모델의 타당성 검사에 이용하는 SPN 모델에 대한 개념과 DEVS 모델과 행위적으로 동등한 SNP 모델로 변환을 위한 관점을 제조명하다. 동일한 관점에서 두 모델의 상태표현이 같도록 DEVS 모델이 SPN 모델로 표현됨을 보이는 변환이론을 제시하고 변환이론을 바탕으로 모델 변환과정을 제시한다. 모델 변환이론과 변환고정을 기본으로 타당성 검사를 위한 새로운 동질함수(homogeneous function)를 정의하고 이와 함께 SPN 모델의 특성을 이용하여 DEVS 모델에 대한 타당성 검사 방법을 새롭게 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.585-586
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• 2009

홉필드 네트웍은 패턴 매칭과 더불어 최적화 문제를 푸는 도구로 사용될 수 있다. Ali에 의해 제안된 최적 경로 탐색 알고리즘을 개선하여 계산량을 대폭 줄이고 효과적으로 최적 경로를 탐색할 수 있다. 노드의 제곱인 브랜치수의 뉴런이 필요한 Ali 알고리즘은 탐색 네트워크가 커지면 많은 시간이 소요되는 단점이 있다. 본 논문은 계산량은 줄이면서 효과적으로 최적 경로를 탐색하는 방법을 제안한다.

• Tuberculosis and Respiratory Diseases
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• v.67 no.2
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• pp.105-112
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• 2009

Background: Solitary pulmonary nodules (SPN) are encountered incidentally in 0.2% of patients who undergo chest X-ray or chest CT. Although SPN has malignant potential, it cannot be treated surgically by biopsy in all patients. The first stage is to determine if patients with SPN require periodic observation and biopsy or resection. An important early step in the management of patients with SPN is to estimate the clinical pretest probability of a malignancy. In every patient with SPN, it is recommended that clinicians estimate the pretest probability of a malignancy either qualitatively using clinical judgment or quantitatively using a validated model. This study examined whether Bayesian analysis or multiple logistic regression analysis is more predictive of the probability of a malignancy in SPN. Methods: From January 2005 to December 2008, this study enrolled 63 participants with SPN at the Kangnam Sacred Hospital. The accuracy of Bayesian analysis and Bayesian analysis with a FDG-PET scan, and Multiple logistic regression analysis was compared retrospectively. The accurate probability of a malignancy in a patient was compared by taking the chest CT and pathology of SPN patients with <30 mm at CXR incidentally. Results: From those participated in study, 27 people (42.9%) were classified as having a malignancy, and 36 people were benign. The result of the malignant estimation by Bayesian analysis was 0.779 (95% confidence interval [CI], 0.657 to 0.874). Using Multiple logistic regression analysis, the result was 0.684 (95% CI, 0.555 to 0.796). This suggests that Bayesian analysis provides a more accurate examination than multiple logistic regression analysis. Conclusion: Bayesian analysis is better than multiple logistic regression analysis in predicting the probability of a malignancy in solitary pulmonary nodules but the difference was not statistically significant.

• Tuberculosis and Respiratory Diseases
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• v.55 no.6
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• pp.589-596
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• 2003

Background : The solitary pulmonary nodule(SPN) presents a diagnostic dilemma to the physician and the patients in the our nation with high incidence of tuberculoma. We could not exclude whether the SPN was benign or malignant by the change of the size at chest radiograph and findings of chest CT. Recently, positron emission tomography(PET) have been tried as the differential diagnostic method of SPN. We evaluated the efficacy of PET for differentiating malignant from benign SPN and the relationship between standardized uptake values(SUV) of PET and serum glucose. Method : Between January 2001 and July 2002, sixty-one patients with pulmonary nodule were examined by the chest CT and PET. The SPN has been finally diagnosed by the transthorasic needle aspiration and biopsy, bronchoscopic biopsy, and open lung biopsy. Results : Forty eight patients had a malignant nodule(23 squamous cell lung carcinoma, 16 adenocarcinoma, 9 small cell lung cancer) and thirteen patients had a benign nodule(3 tuberculoma, 9 inflammatory granuloma, 1 cryptococcosis). The mean size of malignant and benign nodule was 40.6 mm and 20.0 mm, respectively. All malignant nodules showed a marked increase in 18 fluorodeoxyglucose (FDG) uptake. Mean SUV of malignant was $9.52{\pm}5.20$ and benign nodule was $1.61{\pm}3.60$. There were false positive cases with an increase in 18-FDG uptake (2 tuberculoma, 1 inflammatory granuloma). The SUV of malignant nodule in diabetes patients has no difference in non diabetes patients($9.10{\pm}4.51$ vs $9.65{\pm}5.46$). The sensitivity and specificity of the PET scan for SPN were 100%, 77%, respectively. The positive and negative predictive values were 94% and 100%. Conclusion : PET scanning showed highly accurate result in differentiating the malignant and benign SPN. There were no significant differences between the SUV and serum glucose in the patients with lung cancer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.432-436
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• 2002

This study was conducted in 2001 to determine the influence of seed-piece size (SPS) and number (SPN) per mini-tuber produced by hydroponics on growth and yield of potato (Solanum tuberosum L.). Treatments consisted of the combination of six SPS (3, 5, 7, 9, 11, 13g/seed-piece) and four SPN (whole tuber, and two, three, and four pieces/tuber). Percentage sprout emergence at transplanting was higher for seed pieces weighing 7 to 13 g (83.0 to 85.4%) and for three and four pieces per tuber (85.4 and 84.8%). As SPS were increased from 3 to 9 g/piece, total yields markedly increased from 2,052 to 2,924 kg/10a and seed tuber (31 to 250 g) yield from 1,589 to 2,428kg/10a with no further increase with SPS. As SPN was increased from one to three/ tuber, total yields increased from 1,918 to 2,982 kg/10a and seed tuber yields from 1,422 to 2,579 kg/10a with no further increase with SPN. Average tuber weight increased with SPS (46.3 to 71.5 g/tuber) and SPN (56.5 to 64.9 g/tuber).

• The Korean Journal of Nuclear Medicine
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• v.31 no.1
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• pp.83-89
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• 1997

About one-third of radiologically indeterminate solitary pulmonary nodules (SPN) are eventually turned out to be malignant. It is very important to noninvasively determine whether the SPN is malignant or not for the decision of its way of management. PET imaging is highlighted by its unique ability of imaging the function and metabolism of cells. Glucose metabolism is increased in malignant transformed cells. We peformed FDG-PET studies in patients who had radiologically indeterminate SPN and compared the findings with histologic diagnoses to assess the diagnostic accuracy in the detection of malignancy and to decide which parameter is the most suitable for clinical practice among peak SUV (pSUV), average SUV (aSUV), 50/10 ratio, and time-activity curve (TAC), Thirty patients were included in this study and the most useful parameter was pSUV. The sensitivity and specificity in the detection of malignant SPN using 3.5 as a cut off pSUV were both 87%. Interestingly, all 2 false-negative cases were bronch-ioloalveolar carcinoma on histologic examination. If these cases, which could be strongly suspected by CT findings, were excluded, the sensitivity of pSUV was 100%. In conclusion, PET imaging is very helpful for determining malignancy in indeterminate SPN and pSUV is a conveniently measurable parameter which is valuable for interpretation.

• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1263-1270
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• 1997

Background : Differentiation of malignity and benignity is crucial for management of solitary pulmonary nodule(SPN). Clinical parameters such as patient's age, nodule size, smoking history, doubling time, typical calcification in X-ray and CT findings have been reported as helpful in this purpose. However, in most cases, these parameters are not conclusive. Glucose metabolism is increased in cancer tissues including lung cancer tissues. After uptake of 2-[F-18]-fluoro-2-deoxy-D-glucose(FDG), the glucose analogue, by cancer cell, FDG is trapped in the cell without further metabolism after phosphorylation. Thus, hypermetabolic focus in FDG-positron emission tomography (PET) imaging suggest malignancy. We evaluated the diagnostic efficacy of FDG-PET imaging in distinguishing malignant and benign SPN. Methods : We evaluated 28 patients with SPN from Jan. 1995 to Jan. 1997. CT scan of chest and whole-body FDG-PET imaging were performed in all patients. Histologic diagnosis was confirmed by transthoracic fine needle aspiration and biopsy, bronchoscopic biopsy and open thoracotomy. Results : Of the 28 SPN's, 22 nodules were malignant and 6 nodules were benign. FDG-PET imaging diagnosed all malignant nodules correctly as positive, and diagnosed 4 of 6 benign nodules correctly as negative. One tuberculous granuloma and one aspergilloma showed hypennetabolic focus and were diagnosed falsely positve with FDG-PET imaging. In the diagnosis of SPN with FDG-PET, sensitivity and specificity were 100% and 66.7%, positive predictive value and negative predictive value were 92% and 100%. Conclusion : FDG-PET imaging is highly useful noninvasive diagnostic tool in distinguishing between malignant SPN and benign SPN.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.5
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• pp.9-18
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• 1997

The petri net is a graphic model which is adaptable in modeling a complex concurrent parallel ssystem, and it is widely used in the fields of industrial enginering, computer science, electric engineeringand chemistry. Recently, the net is applied to the communication protocol, and extended to represent complex systems. There are several extended petri nets named as TPN (timed petri net), SPN (stochastic petri net), FPN(fuzzy petri net) and TFPN(timed fuzzy petri net). Accodingly, this SPN (stochastic petri net), FPN (fuzzy petri net) and TFPN(timed fuzzy petri net). Accodingly, this paper proposes an advanced communication protocol modeling method using the fuzzy value of the transition and firing delay time as the arguments of the function. The proposed method can produce clearer firing rules, and it is supposed to be used to design and analyse communication protocols in great effection.