• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.661-667
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• 2016

This study evaluated the potential of methodology development of the helical type anchor for soft ground applications. The rotational penetration of the helix structure might make construction-steps easy without the soil spitting and reusable rods could reduce the material cost. Removal of the anchors would be simple as a construction, which can be named the removal anchor. The anchoring resistance after construction is strongly related to the number of helixes resulting in a concise design process. The investigation involved a chamber test with soft soils. In the test, a specially designed and fabricated helical anchor and torque-driver were used to obtain the maximum pull-out resistance of the anchor after rotational penetration. As a result of the tests, The rotational torque and pull-out resistance have a proportional relationship with the strength of the prepared soils. Within the range of the study, the torque of the anchor penetrating increased with increasing pull-out resistance.

• Journal of Korean Society of Forest Science
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• v.95 no.1
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• pp.45-49
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• 2006

The objective of this study is to offer a basic information to select the plant species for environmentally friendly forest road by quantifying the pull-out strength by 18 species used for a revegetation of forest road slope. In the investigation of the root depth growth during 17 months, Indigobush amorpha showed maximum depth of 34.0 cm and perennial ryegrass showed minimum depth of 17.7 cm among all species. The pull-out strength by herb species was $0.054ton/m^2/plant$ for exotic species, $0.085ton/m^2/plant$ for indigenous species, and by shrub species was $0.049ton/m^2/plant$. There were no large difference among herb species in pull-out strength, but shrub species were approximately 9 times stronger than herb species. Thus, for maximizing tightening effect and use of inner soil space. The mixed seeding using herb for erosion control and shrub for shallow failure protection would make up optimal revegetation of forest road slope.

• Journal of Technology Innovation
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• v.13 no.2
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• pp.97-131
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• 2005

This paper has discussed several issues regarding the barriers and opportunities for technological catch-up by the late-comer countries and firms. As one of the barriers to technological catch-up, the paper emphasizes the uncertainty involved with the third stage of learning how to design. The barriers arise because as the forerunner firms refuse to sell or give license to successful catching-up firms who thus have to design the product by themselves. The paper discusses how to overcome this barrier. It also notes that if the crisis of design technology is a push factor for leapfrogging, arrival of new techno-economic paradigm can serve as a pull factor for leapfrogging, serving as a winder of opportunity. The, it emphasized the two risks with leapfrogging, namely the risk of choosing right technology or standards and the risk of creating initial markets, and how to overcome these risks. It discusses how to overcome these risks in leapfrogging, and differentiates diverse forms of knowledge accesses. Then, the paper takes up the issue of whether there can be a single common or several models for catch-up. A common element of catching-up is to enter new markets segments quickly, to manufacture with high levels of engineering excellence, and to be first-to-market by means of the best integrative designs. This observation is supported by the fact that Korea and Taiwan has achieved higher levels of technological capabilities in such sectors as featured by short cycle time of technology. The possibility of two alternative models for catch-up is also discussed in terms of the key difference between Korean and Taiwan, especially in the position toward the source of foreign knowledge and the paths taken toward the final goal of OBM. Taiwan followed the sequential steps of OEM, ODM and OBN, in collaboration or integration with the MNCs. Korean chaebols jumped from OEM directly to OBM even without consolidating design technology.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2359-2368
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• 2013

In this paper, an IRD (internal read data) circuit preventing the reentry into the read mode while keeping the read-out DOUT datum at power-up even if noise such as glitches occurs at signal ports such as an input signal port RD (read) when a power IC is on, is proposed. Also, a pulsed WL (word line) driving method is used to prevent a DC current of several tens of micro amperes from flowing into the read transistor of a differential paired eFuse OTP cell. Thus, reliability is secured by preventing non-blown eFuse links from being blown by the EM (electro-migration). Furthermore, a compared output between a programmed datum and a read-out datum is outputted to the PFb (pass fail bar) pin while performing a sensing margin test with a variable pull-up load in consideration of resistance variation of a programmed eFuse in the program-verify-read mode. The layout size of the 8-bit eFuse OTP IP with a $0.18{\mu}m$ process is $189.625{\mu}m{\times}138.850{\mu}m(=0.0263mm^2)$.

• Journal of Chest Surgery
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• v.41 no.2
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• pp.253-259
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• 2008

Background: The incidence of cervical esophageal cancer is low compared with that of thoracic esophageal cancer, and the role of surgery for cervical esophageal cancer is limited compared with that of radiotherapy or chemotherapy. This study was carried out to determine the outcome of surgery for cervical esophageal cancer. Material and Method: We analyzed retrospectively medical records of 43 patients who had undergone curative surgical resection for cervical esophageal cancer from January 1989 to December 2002. Follow-up loss was absent and the last follow-up was carried out in February 28, 2004. Result: The mean age was 60 years old and the male to female ratio was 40:3. Histologic types were squamous cell carcinoma 42 patients and malignant melanoma 1 patient. The methods used for esophageal reconstruction were gastric pull-up 32 patients, free jejunal graft 7 patients and colon interposition 4 patients. Postoperative complications occurred in 31 patients (72%), and operative mortality occurred in 7 patients (16%). Pathologic stages were I 3, IIa 14, IIb 1, III 19, and IVa 6 patients. Tumor recurrence occurred in 16 patients (44%), and the 3 and 5-year survival rates were 29.3% and 20.9%. Conclusion: The reported surgical results for cervical esophageal cancer showed somewhat high operative mortality, postoperative complication rates and recurrence rates and a low long-term survival rate. It is suggested that multimodality treatment including surgery is needed for the treatment of cervical esophageal cancer because radiotherapy or chemotherapy without surgery could not relieve dysphagia or resolve the tumor completely.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.3
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• pp.75-86
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• 2005

To investigate the fatigue characteristic of upper limbs, this study analyzed RMS(root mean square) and MPF(mean power frequency) value between initial and terminal stages of each experiment condition. And the effect of intermittent endurance time was evaluated using the Borg's CR10 value that was measured for the parts of upper limb. According to the results of ANOVA on RMS value, there were significant difference on the %MVC about push, pull, and down force exertion. Particularly the ANOVA of up force exertion was significant difference on shoulder flexion, elbow flexion and rest time as well as %MVC. The results of ANOVA for MPF value were significant difference on the %MVC in regard of the push and up force exertion. In case of up force exertion, MPF value tended to shift low frequency at all of the experiment conditions. According to the analysis of duty cycle, RMS value considerably increased over 50% duty cycle and as the %MVC increased, the duty cycle affected the increase of RMS value. MPF value for up and down force exertion decreased at 33%, 50% and 67% duty cycle for all of %MVC. Borg CR10 value of hand and forearm were below the 3-point to the 40% of endurance time at 30%MVC and to the 20% of endurance time at 50%MVC with the exception of up force exertion. But Borg CR10 values of upper arm and shoulder at up force exertion were more than 3-point to the 20% of endurance time at 30%MVC and in the start point of endurance time at 50%MVC.

• Journal of Gastric Cancer
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• v.7 no.4
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• pp.200-205
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• 2007

Purpose: The aim of this study was to analyze the post operative outcome of reconstruction with using the stomach after performing total pharyngolaryngoesophagectomy in patients with hypopharyngeal cancer or cervical esophageal cancer. Materials and Methods: We conducted a retrospective chart review of 23 patients who underwent gastric pull up for esophageal substitution at the Department of Surgery, Yonsei University College of Medicine, between January 1991 and December 2006. All the patients had transhiatal esophagectomy performed without thoracotomy. Results: There were seventeen males and six females with a median age of 58.1 years (range: 40-70 years). 19 cases were hypopharyngeal cancer, 13 cases had cancer in the pyriform sinus, 15 cases had cancer in the postcricoid area and one case had cancer in the glottic area. The rest were cervical esophageal cancers. The pathologic result was squamous cell carcinoma in all cases. The median total follow-up period was 33 months (range: 1-62 months) and there were two (8.6%) postoperative deaths: one was due to carotid rupture and the other was due to hepatic failure with liver metastasis. The complications were leakage in 1 patient (4.4%), pneumothorax in 1 patient (4.4%) and pneumonia in 1 patient (4.4%). Conclusion: The use of stomach for esophageal reconstruction has many benefits for treating hypopharyngeal cancer or cervical esophageal cancer, So, we made sure there was a sufficient length for the anastomosis after pharyngolaryngoesophagectomy and a rich blood supply from the stomach. There was a low incidence of the leakage at the anastomotic site, along with a low incidence of stenosis and bleeding.

• Journal of Chest Surgery
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• v.57 no.1
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• pp.62-69
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• 2024

Background: Cervical esophageal cancer is a rare malignancy that requires specialized care. While definitive chemoradiation is the standard treatment approach, surgery remains a valuable option for certain patients. This study examined the surgical outcomes of patients with cervical esophageal cancer. Methods: The study involved a retrospective review and analysis of 24 patients with cervical esophageal cancer. These patients underwent surgical resection between September 1994 and December 2018. Results: The mean age of the patients was 61.0±10.2 years, and 22 (91.7%) of them were male. Furthermore, 21 patients (87.5%) had T3 or T4 tumors, and 11 (45.8%) exhibited lymph node metastasis. Gastric pull-up with esophagectomy was performed for 19 patients (79.2%), while 5 (20.8%) underwent free jejunal graft with cervical esophagectomy. The 30-day operative mortality rate was 8.3%. During the follow-up period, complications included leakage at the anastomotic site in 9 cases (37.5%) and graft necrosis of the gastric conduit in 1 case. Progression to oral feeding was achieved in 20 patients (83.3%). Fifteen patients (62.5%) displayed tumor recurrence. The median time from surgery to recurrence was 10.5 months, and the 1-year recurrence rate was 73.3%. The 1-year and 3-year survival rates were 75% and 33.3%, respectively, with a median survival period of 17 months. Conclusion: Patients with cervical esophageal cancer who underwent surgical resection faced unfavorable outcomes and relatively poor survival. The selection of cases and decision to proceed with surgery should be made cautiously, considering the risk of severe complications.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.320-329
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• 2005

The use of diverse methods for the retaining system has been continuously increased in order to maintain the stability during excavation. However, ground anchor system occasionally may have the restriction in urban excavation sites nearby the existing structures because of space limitation. In this case, soil nailing system with relatively short length of nails could be efficiently useful as an alternative method. The general soil nailing support system, however, may result in excessive deformations particularly in excavating the zone of weak soils or nearby the existing structures. Therefore, applying the pretension force to the soil nails then could play important roles to reduce deformations mainly in an upper part of the nailed-soil excavation system as well as to improve the local slope stability. In this study, a newly modified soil nailing technology named as the PSN(Pretention Soil Nailing) is developed to reduce both facing displacements and ground surface settlements during top-down excavation process as well as to increase the global slope stability. Up to now, the PSN system has been investigated mainly focusing on an establishment of the design procedure. In the present study, the field tests including pull-out tests were fulfilled to investigate the behavior of characteristics for PSN system. All results of tests were also analyzed to provide a fundamental and efficient design.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.12 s.103
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• pp.1186-1193
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• 2005

In this paper, a new 3 dB branch line hybrid using asymmetric spiral-shaped defected ground structure(DGS) microstrip is proposed. The proposed branch line hybrid suppresses the 2nd and the 3rd harmonic component effectively. Also a DGS $\lambda$/4 bias line that can suppress high frequency harmonics as well as low frequency intermodulation component is proposed. With the harmonic termination tuner using the proposed hybrid and the harmonic blocking bias line, the 2nd and the 3rd harmonic components of the fabricated amplifier that operated in IMT-2000 basestation transmitting band were suppressed up 25 dB and 27 dB, respectively. The proposed harmonic load-pull setup of amplifier is more easily accomplished with proposed circuits than the previous.