• Journal of IKEEE
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• v.26 no.1
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• pp.67-76
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• 2022

In this paper, we propose a new algorithm to improve the accuracy of the Wi-Fi access point (AP) positioning technique. The proposed algorithm based on evaluating the trustworthiness of the signal strength quality of each measurement node is superior to other existing AP positioning algorithms, such as the centroid, weighted centroid, multilateration, and radio distance ratio methods, owing to advantages such as reduction of distance errors during positioning, reduction of complexity, and ease of implementation. To validate the performance of the proposed algorithm, we conducted experiments in a complex indoor environment with multiple walls and obstacles, multiple office rooms, corridors, and lobby, and measured the corresponding AP signal strength value at several specific points based on their coordinates. Using the proposed algorithm, we can obtain more accurate positioning results of the APs for use in research or industrial applications, such as finding rogue APs, creating radio maps, or estimating the radio frequency propagation properties in an area.

• Korean Journal of Head & Neck Oncology
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• v.36 no.2
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• pp.73-77
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• 2020

Ovarian cancer is common malignant disease with high mortality in the female. However, lymph node metastasis in the head and neck of ovarian cancer is very rare than in para-aortic, pelvic lymph node. A 49-year-old female patient came to our clinic with a left neck mass. After total thyroidectomy and left selective neck dissection for the cervical neck level II, III, IV, V, VI for ovarian cancer and thyroid cancer, she had already undergone chemotherapy (Paclitaxel+Carboplatin) 18 month ago. CT scan showed only lymph node enlargement in left neck level II. Positron emission tomography-computed tomography (PET-CT) revealed a hypermetabolic lesion in same area but no other hypermetabolic lesion, especially in the pelvic and abdominal cavity. Fine needle aspiration cytology revealed metastatic carcinoma. The serum level of CA-125 was elevated to 43.8U/mL, whereas other tumor markers (CA 19-9, CEA) were in the normal range. She underwent a revision of selective neck lymph node dissection for the cervical neck levels I, II, and III, and on the review of surgical pathology, metastatic carcinoma was suspected. Thus, we performed immunohistochemical staining for the tissue; as a result, it was finally diagnosed as metastatic ovarian cancer (positive for CK7, ER and PR, and negative for CK20). Adjuvant chemotherapy (Paclitaxel+Carboplatin) was planned on the tumor board, and the patient successfully received chemotherapy.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5517-5523
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• 2012

Purpose: To evaluate the diagnostic accuracy of ultrasonograph and fine-needle aspiration cytologic examination (USG-FNAC) in the staging of axillary lymph node metastasis in breast cancer patients.Methods: We conducted an electronic search of the literature addressing the performance of USG-FNAC in diagnosis of axillary lymph node metastasis in databases such as Pubmed, Medline, Embase, Ovid and Cochrane library. We introduced a series of diagnostic test indices to evaluate the performance of USG-FNAC by the random effect model (REM), including sensitivity, specificity, likelihood ratios, and diagnostic odds ratios and area under the curve (AUC). Results: A total of 20 studies including 1371 cases and 1289 controls were identified. The pooled sensitivity was determined to be 0.66 (95% CI 0.64-0.69), specificity 0.98 (95% CI 0.98-0.99), positive likelihood ratio 22.7 (95% CI 15.0-34.49), negative likelihood ratio 0.32 (95% CI 0.25-0.41), diagnostic OR 84.2 (95% CI 53.3-133.0). Due to the marginal threshold effect found in some indices of diagnostic validity, we used a summary SROC curve to aggregate data, and obtained a symmetrical curve with an AUC of 0.942. Conclusion: The results of this meta-analysis indicated that the USG-FNAC techniques have acceptable diagnostic validity indices and can be used for early staging of axillary lymph node in breast cancer patients.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.2
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• pp.97-100
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• 1998

Systemic lupus erythematosus is a severe cutaneous-systemic disorder of unknown etiology, It is represented with erythematous patches on the face in a so-called butterfly distribution, and characteristically classified as an autoimmune disease with antinuclear antibodies. The autoimmune diseases such as systemic lupus erythematosus, $Sj{\ddot{o}}gren$ syndrome, rheumatoid arthritis have been associated with lymphoid malignancy - leukemia, malignant lymphoma - which could involve various organs(spleen, liver, brain, mediastinal lymph node, supraclavicular lymph node, inguinal lymph node, cervical lymph node etc.). Many authors have studied about the association of systemic lupus erythematosus and malignant lymphoma, but exact etiology is still unknown. A common viral etioloty for systemic lupus erythematosus has been suggested since virus-like particles have been found in the glomerular endothelium of patients with systemic lupus erythematosus. These oncogenic viruses may be responsible for the higher frequency of malignant lymphoma in patients with systemic lupus erythematosus. In the other theory, the causes of malignant lymphoma are the defect of immune system due to systemic lupus erythematosus and the long-term use of therapeutics for treatment of systemic lupus erythematosus. When the cellular immune system(delayed hypersensitivity) is impaired by immunosuppressive drugs, it is likely that the body is no longer able to recognize and reject malignant cells as they arise; they continue to grow and divide unhindered. The impairment of the cellular immune system may allow growth of oncogenic virus or the survival of neoplatic tissues. 47-year old female patient treated systemic lupus erythematosus with steroid and immunosuppressive drugs for 5 years visited to our hospital due to elevated mass on left upper anterior maxilla area. By performing biopsy, we diagnosed this lesion as malignant lymphoma and referred to oncologist for chemotherapy. So we report a case of malignant lymphoma due to systemic lupus erythematosus with review of literatures.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.7
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• pp.1412-1418
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• 2005

Recently, more and more portable terminals probably have multiple interfaces to be connected to different access technologies. Each technology has its specific characteristics in terms of coverage area, bandwidth, reliability, etc. For example, the mobile node is equipped with three heterogeneous interfaces; IEEE 802.1lb MLAM link, CDMA Cellular link, and 802.16 WiMAX link These mobile nodes may be reachable through different links at the same time or use each interface alternately depending on the network environment. As like this, the portable terminal equipped multiple interfaces can have many benefits; it should be connect to Internet through other interface in case of occurring to failure for currently activate interface, and it should share a mount of traffic efficiently per interface etc. This environment is called end node Multihoming. However, current most Internet protocols are designed originally with single interface in mind. So these potocols do not provide methods for supporting simultaneous diffentiated use of multiple access technologies. In this paper, firstly we have to refer technical consideration items to use multiple interfaces based on IPv6 simultaneously. And we should propose extended registration mechanism for multiple addresses being acquired from interfaces to support reliable accessibility and vertical handover.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.9
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• pp.2143-2149
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• 2010

An agent based geographic routing protocol is proposed to improve the well-known geographic routing protocol-GPSR routing protocol. In the proposed scheme, the agent is selected by sink node which concern about the source node's position as well as agent candidate's state. So packets will first be forwarded to agent and next step is to be forwarded to their final goal- sink node from agent. During the next hop selection process, nodes select their neighbors by considering not only position but also their average available buffer size. This results in efficient selection of next hop node in congestion area, and then increases the successful packet delivery ratio. The simulation is conducted for two scenarios: general number of connections and large number of connections in our map. Results show that new method with agent achieves improved performance in successful packet delivery ratio when compares to GPSR without our scheme.

• Archives of Plastic Surgery
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• v.41 no.3
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• pp.258-263
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• 2014

Background For early breast cancer patients, skin-sparing mastectomy or nipple-sparing mastectomy with sentinel lymph node biopsy has become the mainstream treatment for immediate breast reconstruction in possible cases. However, a few cases of skin necrosis caused by methylene blue dye (MBD) used for sentinel lymph node localization have been reported. Methods Immediate breast reconstruction using a silicone implant was performed on 35 breasts of 34 patients after mastectomy. For sentinel lymph node localization, 1% MBD (3 mL) was injected into the subareolar area. The operation site was inspected in the postoperative evaluation. Results Six cases of immediate breast reconstruction using implants were complicated by methylene blue dye. One case of local infection was improved by conservative treatment. In two cases, partial necrosis and wound dehiscence of the incision areas were observed; thus, debridement and closure were performed. Of the three cases of wide skin necrosis, two cases underwent removal of the dead tissue and implants, followed by primary closure. In the other case, the breast implant was salvaged using latissimus dorsi musculocutaneous flap reconstruction. Conclusions The complications were caused by MBD toxicity, which aggravated blood disturbance and skin tension after implant insertion. When planning immediate breast reconstruction using silicone implants, complications of MBD should be discussed in detail prior to surgery, and appropriate management in the event of complications is required.

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.507-513
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• 2005

This paper proposes a fast handoff scheme between PDSNs in 3GPPs network for a mobile node. It introduces a method by which handoff can be performed without reestablishing PPP connection that may occur in the process of performing handoff between PDSNs. The method for handoff between PDSNs which provide packet services to a mobile node, requires that the PDSNs should receive subscribers information about mobile nodes from their neighbor PDSNs forming a communication network. When the PDSN recognizes the mobile node moving into its coverage area, it can quickly establish a communication channel with the mobile node based on the already received subscriber information. As a result, handoff is performed without reestablishing PPP. Accordingly, handoff between PDSNs can be performed faster, removing time needed for establishing a PPP session with a terminal and for terminating a previously set up PPP session.

• Journal of Digital Convergence
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• v.13 no.2
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• pp.127-133
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• 2015

In order for location information to deliver the collected information, it needs Sensor Nodes in an environment of Sensor Network. Each sensor sends data to a base station through the process of routing in a wireless sensor network environment. Therefore, Offering accurate location information is very important in a wireless sensor network environment. Most of existed routing methods save all the informations of nodes at the area of 1-hop. In order to save these informations, unnecessary wasted energy and traffics are generated. Routing Protocol proposed in this paper doesn't save node's location information, and doesn't exchange any periodic location information to reduce wasted energy. It includes transmission range of source nodes and nodes with the location information, however it doesn't include any nodes' routing near 1-hope distance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.493-495
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• 2016

In this paper, we propose an alternative method of collecting image data and changing nodes in wireless sensor networks based sensing disaster systems configured with zigbee using quad copter. It is difficult to observe a wide area caused by existing fixed video cameras in the wireless sensor network system using a conventional image-based. Also the nodes don't have provide to alternate methodology in situations when missing due to a disaster or destruction. In this paper, to use wearing the IP camera and the communication node to the quad copter, it provides a method to take advantage of as improving an alternative node of the reliability of the sensor node. The results show to improve the reliability of the sensor nodes and real-time status information through a video quad Copt than conventional systems.