이중 구조의 파티클 필터를 이용한 강인한 위치추적

윤근호(Keunho Yun),김대진(Daijin Kim),방승양(Sung-Yang Bang) 한국정보과학회 2006 정보과학회논문지 : 소프트웨어 및 응용 Vol.33 No.12

위치 인식은 유비쿼터스 컴퓨팅 환경상의 중요한 부분이지만 많은 연구에도 불구하고 아직 완벽한 시스템은 존재하지 않는 상황이다. 본 연구에서는 다양한 위치 추적 시스템 중 가장 널리 사용되는 RFID 시스템을 이용하지만 수신된 RSSI 신호는 리더와 태그 안테나의 방향, 각도, 간섭에 매우 민감하여 기존 알고리즘인 파티클 필터를 이용하면 정확한 위치 추정이 힘들다. 이를 극복하기 위해, 본 연구에서는 이중 구조의 파티클 필터를 가진 강인한 위치 추적 시스템을 제안한다. 이 시스템은 하단부에서 회귀분석이나 SVM 분류기법을 이용하여 대략적인 위치를 확인한 다음, 상단부에서 파티클 필터를 이용하여 위치, 속도, 방향을 추정하는 계층적 구조를 갖고 있다. 그리고 계층 구조상에 움직임 특성이 갖는 여러 제약 사항을 반영하여 위치 추정 성능을 향상시킨다. 제안한 위치 추정 시스템을 실제 상황에 적용하고자 리더와 서버간을 스타 메쉬 네트워크로 연결하여 태그를 소지한 사람과 물체의 위치를 제안한 알고리즘을 이용하여 추정하였다. 실험 결과 제안한 위치 추적 시스템이 기존의 파티클 필터를 이용한 시스템보다 정확한 위치 추정 성능을 보임을 확인하였고 지하 시설물이 복잡하게 놓여있는 매우 열악한 운영 환경상에서도 실시간 동작을 통해 그 유용성이 입증되었다. The location awareness is an important part of many ubiquitous computing systems, but a perfect location system does not exist yet in spite of many researches. Among various location tracking systems, we choose the RFID system due to its wide applications. However, the sensed RSSI signal is too sensitive to the direction of a RFID reader antenna, the orientation of a RFID tag, the human interference, and the propagation media situation. So, the existing location tracking method in spite of using the particle filter is not working well. To overcome this shortcoming, we suggest a robust location tracking method with a double layered structure, where the first layer coarsely estimates a tag's location in the block level using a regression technique or the SVM classifier and the second layer precisely computes the tag's location, velocity and direction using the particle filter technique. Its layered structure improves the location tracking performance by restricting the moving degree of hidden variables. Many extensive experiments show that the proposed location tracking method is so precise and robust to be a good choice for implementing the location estimation of a person or an object in the ubiquitous computing. We also validate the usefulness of the proposed location tracking method by implementing it for a real-time people monitoring system in a noisy and complicate workplace.

치과병원 원내생 진료실을 경험한 환자에 대한 질적 연구

김용관(Yonggwan Kim),김근호(Keunho Kim),강은희(Eunhee Kang),설양조(Yang-Jo Seol),박신영(Shin-Young Park),임정준(Jungjoon Ihm) 대한치과의사협회 2023 대한치과의사협회지 Vol.61 No.6

Although the predoctoral treatment center is crucial for the training of dentists, they often face the chronic issue of limited patient supply. To address this problem, various measures have been proposed. This study employs grounded theory to examine qualitative data and aims to activate the predoctoral treatment center by targeting patients who have undergone treatment by predoctoral students. Specifically, the study seeks to identify how patients who received treatment by predoctoral students initially sought treatment, their positive and negative experiences during treatment, and the factors that either hindered or facilitated the predoctoral treatment center. Based on these findings, the study provides implications for revitalizing the predoctoral treatment center and suggests potential areas for future research.

Biofunctionalized Ceramic with Self-Assembled Networks of Nanochannels

Jang, Hae Lin,Lee, Keunho,Kang, Chan Soon,Lee, Hye Kyoung,Ahn, Hyo-Yong,Jeong, Hui-Yun,Park, Sunghak,Kim, Seul Cham,Jin, Kyoungsuk,Park, Jimin,Yang, Tae-Youl,Kim, Jin Hong,Shin, Seon Ae,Han, Heung Nam American Chemical Society 2015 ACS NANO Vol.9 No.4

<P>Nature designs circulatory systems with hierarchically organized networks of gradually tapered channels ranging from micrometer to nanometer in diameter. In most hard tissues in biological systems, fluid, gases, nutrients and wastes are constantly exchanged through such networks. Here, we developed a biologically inspired, hierarchically organized structure in ceramic to achieve effective permeation with minimum void region, using fabrication methods that create a long-range, highly interconnected nanochannel system in a ceramic biomaterial. This design of a synthetic model-material was implemented through a novel pressurized sintering process formulated to induce a gradual tapering in channel diameter based on pressure-dependent polymer agglomeration. The resulting system allows long-range, efficient transport of fluid and nutrients into sites and interfaces that conventional fluid conduction cannot reach without external force. We demonstrate the ability of mammalian bone-forming cells placed at the distal transport termination of the nanochannel system to proliferate in a manner dependent solely upon the supply of media by the self-powering nanochannels. This approach mimics the significant contribution that nanochannel transport plays in maintaining living hard tissues by providing nutrient supply that facilitates cell growth and differentiation, and thereby makes the ceramic composite “alive”.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2015/ancac3.2015.9.issue-4/acsnano.5b01052/production/images/medium/nn-2015-010525_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn5b01052'>ACS Electronic Supporting Info</A></P>

The value of the primary tumor SUVmax in prediction of central lymph node metastasis in cN0 papillary thyroid microcarcinoma

Jungbin KIM,Hyunjin CHO,Geumhee GWAK,Keunho YANG,Ye Young SEO,Inseok PARK 대한외과학회 2019 대한외과학회 학술대회 초록집 Vol.2019 No.10

Progesterone Receptor Expression as a Prognostic Factor in Luminal B Breast Cancer

Sooyeun Lim,Yoojin Lee,Jungbin Kim,조현진,Keunho Yang,Kyeongmee Park,Jiyoung Kim,Youngjoo Sin,Yeyoung Seo,Geumhee Gwak 한국유방암학회 2022 Journal of Breast Disease Vol.10 No.1

Purpose: The luminal subtype of breast cancer has heterogeneous biological characteristics with respect to the expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor-2 (HER2), and Ki-67. We analyzed luminal B breast cancer subcategorized by PR expression and identified clinically relevant prognostic factors. Methods: We collected the clinical and pathologic data of 247 breast cancer patients (stage 1-4) who were diagnosed with luminal B subtype, defined as ER- and/or PR-positive and/or HER2-positive and with a high Ki-67 proliferation index (>14%). We classified them into PR intact and PR low groups according to PR expression pattern. We also analyzed the clinical and pathological data of each group, including age at diagnosis, tumor size, node metastasis, breast and axillary operative method, margin involvement, tumor-node-metastasis (TNM) stage, histological grade, nuclear grade, number of tumors, and expression of ER, PR, Ki-67, and Bcl-2; evaluated recurrence or metastatic characteristics; and analyzed disease-free survival (DFS) and overall survival (OS) in both groups. Results: Among the 247 luminal B breast cancer patients (stage 1-4), 141 were classified into the PR intact group (57.1%) and 106 into the PR low group (42.9%). The PR low group was associated with age >50 years (p=0.001), low Bcl-2 expression (p<0.001), and high proportion of mastectomies (p<0.001). DFS and OS were significantly lower in the PR low group (p=0.025 and 0.024, respectively). Conclusion: This study showed that decreased in PR expression (PR low group) in luminal B breast cancer was related to poor prognosis compared to normal PR expression (PR intact group).

Development of Molecular Markers for Predicting Radish (Raphanus sativus) Flesh Color Based on Polymorphisms in the RsTT8 Gene

Soyun Kim,Man-Ho Oh,Keunho Yun,Ju Young Ahn,Ju Yeon Yang,Hayoung Song,Yoonkang Hur 한국원예학회 2021 한국원예학회 학술발표요지 Vol.2021 No.10

Red radish (Raphanus sativus L.) cultivars are a rich source of health-promoting anthocyanins and are considered a potential source of natural colorants used in the cosmetic industry. However, the development of red radish cultivars via conventional breeding is very difficult, given the unusual inheritance of the anthocyanin accumulation trait in radishes. Therefore, molecular markers linked with radish color are needed to facilitate radish breeding. Here, we characterized the RsTT8 gene isolated from four radish genotypes with different skin and flesh colors. Sequence analysis of RsTT8 revealed a large number of polymorphisms, including insertion/deletions (InDels), single nucleotide polymorphisms (SNPs), and simple sequence repeats (SSRs), between the red-fleshed and white-fleshed radish cultivars. To develop molecular markers on the basis of these polymorphisms for discriminating between radish genotypes with different colored flesh tissues, we designed four primer sets specific to the RsTT8 promoter, InDel, SSR, and WD40/acidic domain (WD/AD), and tested these primers on a diverse collection of radish lines. Except for the SSR-specific primer set, all primer sets successfully discriminated between red-fleshed and white-fleshed radish lines. Thus, we developed three molecular markers that can be efficiently used for breeding red-fleshed radish cultivars.

Clinicopatholgic Characteristics to the Relapse on Ductal Carcinoma In Situ: Ki-67 Index as the Most Influential Prognostic Factor

Minsuh Park,Geumhee Gwak,Jungbin Kim,조현진,Keunho Yang,Yujin Lee,Kyeongmee Park,Jiyoung Kim,Youngjoo Shin,Yeyoung Seo 한국유방암학회 2022 Journal of Breast Disease Vol.10 No.1

Purpose: The biggest concern related to ductal carcinoma in situ (DCIS) is local recurrence and recurrence patterns. The purpose of this study was to investigate the relationship between clinicopathological factors and relapse in patients treated with DCIS. Methods: We reviewed medical records of 104 patients who were diagnosed as DCIS between January 1999 and December 2015 at a single institute. We compared and analyzed clinicopathological factors such as age at diagnosis, preoperative lesions on ultrasonography, preoperative tumor markers, operation methods in the breast, histological grade, nuclear grade, resection margin, comedonecrosis, estrogen receptor/progesterone receptor expression, human epidermal factor receptor 2/neu expression, Ki-67, postoperative implementation of adjuvant hormonal therapy, and radiotherapy by dividing them into recurrent and non-recurrent groups. Results: Seventeen patients (16.3%) of 104 patients relapsed in the ipsilateral or contralateral breast. The median follow-up period of non-relapsed group was 4.9 years (range, 0.5–19.15) and the median follow-up period of relapsed group was 3.5 years (range, 1.4–14.13). Clinicopathological factors that were significantly related to relapse were nuclear grade (p=0.022) and Ki-67 (p=0.025) based on the results of chi-square or Fisher’s exact analysis. In multivariate analysis using logistic regression, Ki-67 (p=0.021) was significantly associated with DCIS relapse. Conclusion: This study suggested that the higher Ki-67 over 14% was strongly associated with DCIS relapse.

Characteristics of HER2-Positive Breast Cancer according to HER2 2+/Low or 3+/High Classification by Immunohistochemistry Assay: Study of 205 Cases Treated in a Single Center

Changhee Lee,Inseok Park,Jungbin Kim,Hyunjin Cho,Keunho Yang,Yujin Lee,Kyeongmee Park,Jiyoung Kim,신영주,Geumhee Gwak 한국유방암학회 2021 Journal of Breast Disease Vol.9 No.1

Purpose: To investigate the characteristics of HER2-positive breast cancer according to HER2 low (2+) or high (3+) classification using immunohistochemistry (IHC). Methods: Data were collected from 205 HER2-positive breast cancer patients in the final assay, regardless of IHC or in situ hybridization (ISH). We thus classified patients into two groups: HER2 2+/low and HER2 3+/high based on the IHC assay. We subsequently compared the clinical and pathological characteristics between groups. Results: The median patient age was 49 years in the HER2 2+/low group and 53 years in the HER2 3+/high group. We observed a significantly lower Allred score for estrogen receptor (ER) and progesterone receptor (PR) (0-6) (p<0.001), less lymphatic invasion (LI), (p=0.010), neural invasion (p=0.041), higher Ki-67 (p=0.001), and lower Bcl-2 (p<0.001) in the HER2 3+/high group than in the HER2 2+/low group. Lymph node recurrence was more frequently observed in the HER2 2+/low group than in HER2 3+/high group (p=0.005). Disease-free survival (DFS) was better in the HER2 3+/high group than in the HER2 2+/low group (p=0.028), but there were no significant differences in overall survival between the groups (p=0.233). Conclusion: The HER2 3+/high group was associated with lower ER and PR expression, less LI, higher Ki-67, and lower Bcl-2 than that in HER2 2+/low group in HER2-positive breast cancer. Furthermore, compared to the HER2 2+/low group, the HER2 3+/high group had an improved DFS.

Epigenetic regulation of the potential tumor suppressor gene, hLHX6.1, in human cervical cancer

JUNG, SAMIL;JEONG, DONGJUN;KIM, JINSUN;YI, LISHA;KOO, KEUNHOE;LEE, JAEHYOUK;KIM, CHANG-JIN;KIM, CHANG-HWAN;AN, SUNGWHAN;YANG, YOUNG;LIM, JONG-SEOK;KIM, KEUN IL;LEE, MYEONG-SOK Sookmyung Women's University Research Institute of 2011 여성과 건강 Vol.6 No.2

It is well known that the Homo sapiens LIM homeobox domain 6 gene (hLHX6), a putative transcription regulator, controls the differentiation and development of neural and lymphoid cells, particularly in the central nervous system. In this study, we investigated hLHX6.1 (an isoform of hLHX6), which functions as a tumor suppressor gene in the cervix. Firstly, the methylation levels of the h내X6 and hLHX6.1 promoters were investigated in 8 cervical cancer cell lines and human tissue samples with a distinctive degree of malignant transformation. In spite of the presence of multiple cytosine guanine dinucleotides (CpG islands) in 2 proximal promoters of the hLHX6 and hLHX6.1 genes, only the HLHX6.1 promoters were found to be mostly hyper¬methylated and associated with transcriptional silencing by promoter methylation, whereas the hLHX6 promoters were not. Methylation levels in the hLX6.1 promoter were also found to be strongly related to cervical cancer development. The level of hLHX6.1 gene expression was found to be relatively high in normal cells, in which the hLHX6.1 promoter was mostly unmethylated. However, the hLHX6.1 gene expression was down-regulated or undetectable in cervical cancer cell lines and cancer tissues, in which the hLHX6.1 promoter was hypermethylated. This epigenetic alteration in the hLHX6.1 promoter begins at a relatively early stage, suggesting its potential as a biomarker for the early diagnosis and prevention of cervical cancer. Moreover, the overexpression of the hLHX6.1 gene in cervical cancer cells suppressed the tumorigenic phenotype, as shown by soft agar colony formation and migration assays, suggesting that hLHX6.1 could be a new tumor suppressor gene in the cervix.

네트워크 이동성 환경에서 분산 바인딩 갱신 기법

김훈(Hoon Kim),김진수(JinSoo Kim),양순옥(SoonOk Yang),이근호(KeunHo Lee),송의성(Ui-Sung Song),황종선(Chong-Sun Hwang) 한국정보과학회 2005 한국정보과학회 학술발표논문집 Vol.32 No.2

네트워크가 이동하는 환경을 지원하기 위하여 IETF에서는 NEMO(NEtwork MObility)를 제안하였다. NEMO에서는 이동 네트워크 내부에 이동하는 노드를 가질 수 있기 때문에 이동 네트워크 노드와 이동 네트워크 간의 복잡한 구조로 인하여 중첩되는 라우팅 문제가 발생한다. 이로 인하여 이동 네트워크 환경에서의 라우팅 최적화에 관한 연구가 진행되고 있다. 하지만 라우팅 최적화는 홈 에이전트 또는 상대 노드와 직접 통신을 하기 때문에 이동 네트워크가 이동 시마다 갱신된 위치를 알려주어야 하며 이로 인하여 바인딩 갱신 폭풍 문제가 발생한다. 본 논문에서는 분산 바인딩 갱신기법을 제안하여 바인딩 갱신 폭풍으로 인하여 발생되는 대역폭 감소와 바인딩 갱신 지연 문제를 해결하고 시뮬레이션을 통하여 제안기법의 성능을 분석하였다.